diff --git a/app/assets/javascripts/admin/addon/controllers/admin-api-keys-new.js b/app/assets/javascripts/admin/addon/controllers/admin-api-keys-new.js
index 8d56042a67..c90316369a 100644
--- a/app/assets/javascripts/admin/addon/controllers/admin-api-keys-new.js
+++ b/app/assets/javascripts/admin/addon/controllers/admin-api-keys-new.js
@@ -3,6 +3,7 @@ import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { isBlank } from "@ember/utils";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { get } from "@ember/object";
 import showModal from "discourse/lib/show-modal";
 
 export default Controller.extend({
@@ -30,6 +31,10 @@ export default Controller.extend({
   },
 
   actions: {
+    updateUsername(selected) {
+      this.set("model.username", get(selected, "firstObject"));
+    },
+
     changeUserMode(value) {
       if (value === "all") {
         this.model.set("username", null);
diff --git a/app/assets/javascripts/admin/addon/controllers/admin-email-preview-digest.js b/app/assets/javascripts/admin/addon/controllers/admin-email-preview-digest.js
index 4210f9cff2..1a6fbf2184 100644
--- a/app/assets/javascripts/admin/addon/controllers/admin-email-preview-digest.js
+++ b/app/assets/javascripts/admin/addon/controllers/admin-email-preview-digest.js
@@ -2,6 +2,7 @@ import { empty, notEmpty, or } from "@ember/object/computed";
 import Controller from "@ember/controller";
 import EmailPreview from "admin/models/email-preview";
 import bootbox from "bootbox";
+import { get } from "@ember/object";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 
 export default Controller.extend({
@@ -14,6 +15,10 @@ export default Controller.extend({
   htmlEmpty: empty("model.html_content"),
 
   actions: {
+    updateUsername(selected) {
+      this.set("username", get(selected, "firstObject"));
+    },
+
     refresh() {
       const model = this.model;
 
diff --git a/app/assets/javascripts/admin/addon/controllers/modals/admin-merge-users-prompt.js b/app/assets/javascripts/admin/addon/controllers/modals/admin-merge-users-prompt.js
index 2a088dff31..98f60d2395 100644
--- a/app/assets/javascripts/admin/addon/controllers/modals/admin-merge-users-prompt.js
+++ b/app/assets/javascripts/admin/addon/controllers/modals/admin-merge-users-prompt.js
@@ -1,6 +1,6 @@
 import Controller, { inject as controller } from "@ember/controller";
 import ModalFunctionality from "discourse/mixins/modal-functionality";
-import { action } from "@ember/object";
+import { action, get } from "@ember/object";
 import { alias } from "@ember/object/computed";
 import discourseComputed from "discourse-common/utils/decorators";
 
@@ -27,4 +27,9 @@ export default Controller.extend(ModalFunctionality, {
   close() {
     this.send("closeModal");
   },
+
+  @action
+  updateUsername(selected) {
+    this.set("targetUsername", get(selected, "firstObject"));
+  },
 });
diff --git a/app/assets/javascripts/admin/addon/templates/api-keys-new.hbs b/app/assets/javascripts/admin/addon/templates/api-keys-new.hbs
index 7d6219ffac..a8957262df 100644
--- a/app/assets/javascripts/admin/addon/templates/api-keys-new.hbs
+++ b/app/assets/javascripts/admin/addon/templates/api-keys-new.hbs
@@ -25,10 +25,14 @@
 
     {{#if showUserSelector}}
       {{#admin-form-row label="admin.api.user"}}
-        {{user-selector single="true"
-          usernames=model.username
-          placeholderKey="admin.api.user_placeholder"
-          }}
+        {{email-group-user-chooser
+          value=model.username
+          onChange=(action "updateUsername")
+          options=(hash
+            maximum=1
+            filterPlaceholder="admin.api.user_placeholder"
+          )
+        }}
       {{/admin-form-row}}
     {{/if}}
 
diff --git a/app/assets/javascripts/admin/addon/templates/email-preview-digest.hbs b/app/assets/javascripts/admin/addon/templates/email-preview-digest.hbs
index 8d10ac3a8b..c93d048ba6 100644
--- a/app/assets/javascripts/admin/addon/templates/email-preview-digest.hbs
+++ b/app/assets/javascripts/admin/addon/templates/email-preview-digest.hbs
@@ -5,7 +5,13 @@
     <label for="last-seen">{{i18n "admin.email.last_seen_user"}}</label>
     {{date-picker-past value=lastSeen id="last-seen"}}
     <label>{{i18n "admin.email.user"}}:</label>
-    {{user-selector single="true" usernames=username canReceiveUpdates=true}}
+    {{email-group-user-chooser
+      value=username
+      onChange=(action "updateUsername")
+      options=(hash
+        maximum=1
+      )
+    }}
     {{d-button
       class="btn-primary digest-refresh-button"
       action=(action "refresh")
diff --git a/app/assets/javascripts/admin/addon/templates/modal/admin-merge-users-prompt.hbs b/app/assets/javascripts/admin/addon/templates/modal/admin-merge-users-prompt.hbs
index 71f7a404bc..6fea5ee4f0 100644
--- a/app/assets/javascripts/admin/addon/templates/modal/admin-merge-users-prompt.hbs
+++ b/app/assets/javascripts/admin/addon/templates/modal/admin-merge-users-prompt.hbs
@@ -1,10 +1,15 @@
 <div>
   {{#d-modal-body rawTitle=(i18n "admin.user.merge.prompt.title" username=username)}}
     <p>{{html-safe (i18n "admin.user.merge.prompt.description" username=username)}}</p>
-    {{user-selector single=true
-                    placeholderKey="admin.user.merge.prompt.target_username_placeholder"
-                    usernames=targetUsername
-                    autocomplete="discourse"}}
+    {{email-group-user-chooser
+      value=targetUsername
+      autocomplete="discourse"
+      onChange=(action "updateUsername")
+      options=(hash
+        maximum=1
+        filterPlaceholder="admin.user.merge.prompt.target_username_placeholder"
+      )
+    }}
   {{/d-modal-body}}
 
   <div class="modal-footer">
diff --git a/app/assets/javascripts/discourse/app/components/composer-user-selector.js b/app/assets/javascripts/discourse/app/components/composer-user-selector.js
index dc0bc42cfe..1633794f1f 100644
--- a/app/assets/javascripts/discourse/app/components/composer-user-selector.js
+++ b/app/assets/javascripts/discourse/app/components/composer-user-selector.js
@@ -1,13 +1,12 @@
-import discourseComputed, { observes } from "discourse-common/utils/decorators";
 import Component from "@ember/component";
-import I18n from "I18n";
+import discourseComputed from "discourse-common/utils/decorators";
 import putCursorAtEnd from "discourse/lib/put-cursor-at-end";
-import { schedule } from "@ember/runloop";
 
 export default Component.extend({
-  showSelector: true,
-  shouldHide: false,
-  defaultUsernameCount: 0,
+  init() {
+    this._super(...arguments);
+    this.set("_groups", []);
+  },
 
   didInsertElement() {
     this._super(...arguments);
@@ -17,78 +16,34 @@ export default Component.extend({
     }
   },
 
-  @observes("usernames")
-  _checkWidth() {
-    let width = 0;
-    const $acWrap = $(this.element).find(".ac-wrap");
-    const limit = $acWrap.width();
-    this.set("defaultUsernameCount", 0);
-
-    $acWrap
-      .find(".item")
-      .toArray()
-      .forEach((item) => {
-        width += $(item).outerWidth(true);
-        const result = width < limit;
-
-        if (result) {
-          this.incrementProperty("defaultUsernameCount");
-        }
-        return result;
-      });
-
-    if (width >= limit) {
-      this.set("shouldHide", true);
-    } else {
-      this.set("shouldHide", false);
-    }
+  @discourseComputed("recipients")
+  splitRecipients(recipients) {
+    return recipients ? recipients.split(",").filter(Boolean) : [];
   },
 
-  @observes("shouldHide")
-  _setFocus() {
-    const selector =
-      "#reply-control #reply-title, #reply-control .d-editor-input";
-
-    if (this.shouldHide) {
-      $(selector).on("focus.composer-user-selector", () => {
-        this.set("showSelector", false);
-        this.appEvents.trigger("composer:resize");
-      });
-    } else {
-      $(selector).off("focus.composer-user-selector");
-    }
-  },
-
-  @discourseComputed("usernames")
-  splitUsernames(usernames) {
-    return usernames.split(",");
-  },
-
-  @discourseComputed("splitUsernames", "defaultUsernameCount")
-  limitedUsernames(splitUsernames, count) {
-    return splitUsernames.slice(0, count).join(", ");
-  },
-
-  @discourseComputed("splitUsernames", "defaultUsernameCount")
-  hiddenUsersCount(splitUsernames, count) {
-    return `${splitUsernames.length - count} ${I18n.t("more")}`;
+  _updateGroups(selected, newGroups) {
+    const groups = [];
+    this._groups.forEach((existing) => {
+      if (selected.includes(existing)) {
+        groups.addObject(existing);
+      }
+    });
+    newGroups.forEach((newGroup) => {
+      if (!groups.includes(newGroup)) {
+        groups.addObject(newGroup);
+      }
+    });
+    this.setProperties({
+      _groups: groups,
+      hasGroups: groups.length > 0,
+    });
   },
 
   actions: {
-    toggleSelector() {
-      this.set("showSelector", true);
-
-      schedule("afterRender", () => {
-        $(this.element).find("input").focus();
-      });
-    },
-
-    triggerResize() {
-      this.appEvents.trigger("composer:resize");
-      const $this = $(this.element).find(".ac-wrap");
-      if ($this.height() >= 150) {
-        $this.scrollTop($this.height());
-      }
+    updateRecipients(selected, content) {
+      const newGroups = content.filterBy("isGroup").mapBy("id");
+      this._updateGroups(selected, newGroups);
+      this.set("recipients", selected.join(","));
     },
   },
 });
diff --git a/app/assets/javascripts/discourse/app/components/invite-panel.js b/app/assets/javascripts/discourse/app/components/invite-panel.js
index 0578836b38..949ce17842 100644
--- a/app/assets/javascripts/discourse/app/components/invite-panel.js
+++ b/app/assets/javascripts/discourse/app/components/invite-panel.js
@@ -20,9 +20,9 @@ export default Component.extend({
   isStaff: readOnly("currentUser.staff"),
   isAdmin: readOnly("currentUser.admin"),
 
-  // If this isn't defined, it will proxy to the user topic on the preferences
-  // page which is wrong.
-  emailOrUsername: null,
+  // invitee is either a user, group or email
+  invitee: null,
+  isInviteeGroup: false,
   hasCustomMessage: false,
   customMessage: null,
   inviteIcon: "envelope",
@@ -41,7 +41,7 @@ export default Component.extend({
 
   @discourseComputed(
     "isAdmin",
-    "emailOrUsername",
+    "invitee",
     "invitingToTopic",
     "isPrivateTopic",
     "groupIds",
@@ -50,7 +50,7 @@ export default Component.extend({
   )
   disabled(
     isAdmin,
-    emailOrUsername,
+    invitee,
     invitingToTopic,
     isPrivateTopic,
     groupIds,
@@ -60,24 +60,22 @@ export default Component.extend({
     if (saving) {
       return true;
     }
-    if (isEmpty(emailOrUsername)) {
+    if (isEmpty(invitee)) {
       return true;
     }
 
-    const emailTrimmed = emailOrUsername.trim();
-
     // when inviting to forum, email must be valid
-    if (!invitingToTopic && !emailValid(emailTrimmed)) {
+    if (!invitingToTopic && !emailValid(invitee)) {
       return true;
     }
 
     // normal users (not admin) can't invite users to private topic via email
-    if (!isAdmin && isPrivateTopic && emailValid(emailTrimmed)) {
+    if (!isAdmin && isPrivateTopic && emailValid(invitee)) {
       return true;
     }
 
     // when inviting to private topic via email, group name must be specified
-    if (isPrivateTopic && isEmpty(groupIds) && emailValid(emailTrimmed)) {
+    if (isPrivateTopic && isEmpty(groupIds) && emailValid(invitee)) {
       return true;
     }
 
@@ -90,7 +88,7 @@ export default Component.extend({
 
   @discourseComputed(
     "isAdmin",
-    "emailOrUsername",
+    "invitee",
     "inviteModel.saving",
     "isPrivateTopic",
     "groupIds",
@@ -98,7 +96,7 @@ export default Component.extend({
   )
   disabledCopyLink(
     isAdmin,
-    emailOrUsername,
+    invitee,
     saving,
     isPrivateTopic,
     groupIds,
@@ -110,24 +108,22 @@ export default Component.extend({
     if (saving) {
       return true;
     }
-    if (isEmpty(emailOrUsername)) {
+    if (isEmpty(invitee)) {
       return true;
     }
 
-    const email = emailOrUsername.trim();
-
     // email must be valid
-    if (!emailValid(email)) {
+    if (!emailValid(invitee)) {
       return true;
     }
 
     // normal users (not admin) can't invite users to private topic via email
-    if (!isAdmin && isPrivateTopic && emailValid(email)) {
+    if (!isAdmin && isPrivateTopic && emailValid(invitee)) {
       return true;
     }
 
     // when inviting to private topic via email, group name must be specified
-    if (isPrivateTopic && isEmpty(groupIds) && emailValid(email)) {
+    if (isPrivateTopic && isEmpty(groupIds) && emailValid(invitee)) {
       return true;
     }
 
@@ -179,7 +175,7 @@ export default Component.extend({
   // Show Groups? (add invited user to private group)
   @discourseComputed(
     "isGroupOwnerOrAdmin",
-    "emailOrUsername",
+    "invitee",
     "isPrivateTopic",
     "isPM",
     "invitingToTopic",
@@ -187,7 +183,7 @@ export default Component.extend({
   )
   showGroups(
     isGroupOwnerOrAdmin,
-    emailOrUsername,
+    invitee,
     isPrivateTopic,
     isPM,
     invitingToTopic,
@@ -197,20 +193,20 @@ export default Component.extend({
       isGroupOwnerOrAdmin &&
       canInviteViaEmail &&
       !isPM &&
-      (emailValid(emailOrUsername) || isPrivateTopic || !invitingToTopic)
+      (emailValid(invitee) || isPrivateTopic || !invitingToTopic)
     );
   },
 
-  @discourseComputed("emailOrUsername")
-  showCustomMessage(emailOrUsername) {
-    return this.inviteModel === this.currentUser || emailValid(emailOrUsername);
+  @discourseComputed("invitee")
+  showCustomMessage(invitee) {
+    return this.inviteModel === this.currentUser || emailValid(invitee);
   },
 
   // Instructional text for the modal.
   @discourseComputed(
     "isPM",
     "invitingToTopic",
-    "emailOrUsername",
+    "invitee",
     "isPrivateTopic",
     "isAdmin",
     "canInviteViaEmail"
@@ -218,7 +214,7 @@ export default Component.extend({
   inviteInstructions(
     isPM,
     invitingToTopic,
-    emailOrUsername,
+    invitee,
     isPrivateTopic,
     isAdmin,
     canInviteViaEmail
@@ -236,9 +232,9 @@ export default Component.extend({
         return I18n.t("topic.invite_reply.to_username");
       } else {
         // when inviting to a topic, display instructions based on provided entity
-        if (isEmpty(emailOrUsername)) {
+        if (isEmpty(invitee)) {
           return I18n.t("topic.invite_reply.to_topic_blank");
-        } else if (emailValid(emailOrUsername)) {
+        } else if (emailValid(invitee)) {
           this.set("inviteIcon", "envelope");
           return I18n.t("topic.invite_reply.to_topic_email");
         } else {
@@ -257,18 +253,18 @@ export default Component.extend({
     return isPrivateTopic ? "required" : "optional";
   },
 
-  @discourseComputed("isPM", "emailOrUsername", "invitingExistingUserToTopic")
-  successMessage(isPM, emailOrUsername, invitingExistingUserToTopic) {
-    if (this.hasGroups) {
+  @discourseComputed("isPM", "invitee", "invitingExistingUserToTopic")
+  successMessage(isPM, invitee, invitingExistingUserToTopic) {
+    if (this.isInviteeGroup) {
       return I18n.t("topic.invite_private.success_group");
     } else if (isPM) {
       return I18n.t("topic.invite_private.success");
     } else if (invitingExistingUserToTopic) {
       return I18n.t("topic.invite_reply.success_existing_email", {
-        emailOrUsername,
+        invitee,
       });
-    } else if (emailValid(emailOrUsername)) {
-      return I18n.t("topic.invite_reply.success_email", { emailOrUsername });
+    } else if (emailValid(invitee)) {
+      return I18n.t("topic.invite_reply.success_email", { invitee });
     } else {
       return I18n.t("topic.invite_reply.success_username");
     }
@@ -295,7 +291,8 @@ export default Component.extend({
   // Reset the modal to allow a new user to be invited.
   reset() {
     this.setProperties({
-      emailOrUsername: null,
+      invitee: null,
+      isInviteeGroup: false,
       hasCustomMessage: false,
       customMessage: null,
       invitingExistingUserToTopic: false,
@@ -346,9 +343,9 @@ export default Component.extend({
       model.setProperties({ saving: false, error: true });
     };
 
-    if (this.hasGroups) {
+    if (this.isInviteeGroup) {
       return this.inviteModel
-        .createGroupInvite(this.emailOrUsername.trim())
+        .createGroupInvite(this.invitee.trim())
         .then((data) => {
           model.setProperties({ saving: false, finished: true });
           this.get("inviteModel.details.allowed_groups").pushObject(
@@ -359,7 +356,7 @@ export default Component.extend({
         .catch(onerror);
     } else {
       return this.inviteModel
-        .createInvite(this.emailOrUsername.trim(), groupIds, this.customMessage)
+        .createInvite(this.invitee.trim(), groupIds, this.customMessage)
         .then((result) => {
           model.setProperties({ saving: false, finished: true });
           if (!this.invitingToTopic && userInvitedController) {
@@ -379,7 +376,7 @@ export default Component.extend({
             this.appEvents.trigger("post-stream:refresh", { force: true });
           } else if (
             this.invitingToTopic &&
-            emailValid(this.emailOrUsername.trim()) &&
+            emailValid(this.invitee.trim()) &&
             result &&
             result.user
           ) {
@@ -407,7 +404,7 @@ export default Component.extend({
     }
 
     return model
-      .generateInviteLink(this.emailOrUsername.trim(), groupIds, topicId)
+      .generateInviteLink(this.invitee.trim(), groupIds, topicId)
       .then((result) => {
         model.setProperties({
           saving: false,
@@ -465,7 +462,23 @@ export default Component.extend({
   @action
   searchContact() {
     getNativeContact(this.capabilities, ["email"], false).then((result) => {
-      this.set("emailOrUsername", result[0].email[0]);
+      this.set("invitee", result[0].email[0]);
     });
   },
+
+  @action
+  updateInvitee(selected, content) {
+    const invitee = content.findBy("id", selected[0]);
+    if (invitee) {
+      this.setProperties({
+        invitee: invitee.id.trim(),
+        isInviteeGroup: invitee.isGroup || false,
+      });
+    } else {
+      this.setProperties({
+        invitee: null,
+        isInviteeGroup: false,
+      });
+    }
+  },
 });
diff --git a/app/assets/javascripts/discourse/app/templates/components/composer-user-selector.hbs b/app/assets/javascripts/discourse/app/templates/components/composer-user-selector.hbs
index 8b4170f9f2..cb6198778b 100644
--- a/app/assets/javascripts/discourse/app/templates/components/composer-user-selector.hbs
+++ b/app/assets/javascripts/discourse/app/templates/components/composer-user-selector.hbs
@@ -1,22 +1,14 @@
-{{#if showSelector}}
-  {{user-selector
+{{email-group-user-chooser
+  id="private-message-users"
+  tabindex="1"
+  autocomplete="discourse"
+  value=splitRecipients
+  onChange=(action "updateRecipients")
+  options=(hash
     topicId=topicId
-    onChangeCallback=(action "triggerResize")
-    id="private-message-users"
-    includeMessageableGroups="true"
-    placeholderKey="composer.users_placeholder"
-    tabindex="1"
-    usernames=usernames
-    hasGroups=hasGroups
-    allowEmails="true"
-    autocomplete="discourse"
-    canReceiveUpdates=true
-  }}
-{{else}}
-  <a href {{action "toggleSelector"}}>
-    <div class="ac-wrap composer-user-selector-limited">
-      <span>{{limitedUsernames}}</span>
-      <span class="btn btn-primary">{{hiddenUsersCount}}</span>
-    </div>
-  </a>
-{{/if}}
+    filterPlaceholder="composer.users_placeholder"
+    includeMessageableGroups=true
+    allowEmails=true
+    autoWrap=true
+  )
+}}
diff --git a/app/assets/javascripts/discourse/app/templates/components/invite-panel.hbs b/app/assets/javascripts/discourse/app/templates/components/invite-panel.hbs
index 8a655640e9..fa808f6ac8 100644
--- a/app/assets/javascripts/discourse/app/templates/components/invite-panel.hbs
+++ b/app/assets/javascripts/discourse/app/templates/components/invite-panel.hbs
@@ -7,7 +7,7 @@
 <div class="body">
   {{#if inviteModel.finished}}
     {{#if inviteModel.inviteLink}}
-      {{generated-invite-link link=inviteModel.inviteLink email=emailOrUsername}}
+      {{generated-invite-link link=inviteModel.inviteLink email=invitee}}
     {{else}}
       <div class="success-message">
         {{html-safe successMessage}}
@@ -18,24 +18,23 @@
       <label class="instructions">{{inviteInstructions}}</label>
       <div class="invite-user-input-wrapper">
         {{#if allowExistingMembers}}
-          {{user-selector
-            fullWidthWrap=true
-            single=true
-            allowAny=true
-            excludeCurrentUser=true
-            includeMessageableGroups=isPM
-            hasGroups=hasGroups
-            usernames=emailOrUsername
-            placeholderKey=placeholderKey
-            allowEmails=canInviteViaEmail
+          {{email-group-user-chooser
             class="invite-user-input"
             autocomplete="discourse"
-            value=emailOrUsername
+            value=invitee
+            onChange=(action "updateInvitee")
+            options=(hash
+              maximum=1
+              allowEmails=canInviteViaEmail
+              excludeCurrentUser=true
+              includeMessageableGroups=isPM
+              filterPlaceholder=placeholderKey
+            )
           }}
         {{else}}
           {{text-field
             class="email-or-username-input"
-            value=emailOrUsername
+            value=invitee
             placeholderKey="topic.invite_reply.email_placeholder"}}
         {{/if}}
         {{#if capabilities.hasContactPicker}}
diff --git a/app/assets/javascripts/discourse/app/templates/composer.hbs b/app/assets/javascripts/discourse/app/templates/composer.hbs
index 0d53c253b1..dac189f589 100644
--- a/app/assets/javascripts/discourse/app/templates/composer.hbs
+++ b/app/assets/javascripts/discourse/app/templates/composer.hbs
@@ -52,11 +52,13 @@
             {{#if model.canEditTitle}}
               {{#if model.creatingPrivateMessage}}
                 <div class="user-selector">
-                  {{composer-user-selector topicId=topicModel.id
-                                           usernames=model.targetRecipients
-                                           hasGroups=model.hasTargetGroups
-                                           focusTarget=focusTarget
-                                           class="users-input"}}
+                  {{composer-user-selector
+                    topicId=topicModel.id
+                    recipients=model.targetRecipients
+                    hasGroups=model.hasTargetGroups
+                    focusTarget=focusTarget
+                    class="users-input"
+                  }}
                   {{#if showWarning}}
                     <label class="add-warning">
                       {{input type="checkbox" checked=model.isWarning tabindex="3"}}
diff --git a/app/assets/javascripts/discourse/tests/acceptance/composer-actions-test.js b/app/assets/javascripts/discourse/tests/acceptance/composer-actions-test.js
index 95c3585143..a9f4ff0cf7 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/composer-actions-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/composer-actions-test.js
@@ -62,7 +62,9 @@ acceptance("Composer Actions", function (needs) {
     await composerActions.selectRowByValue("reply_as_private_message");
 
     assert.equal(
-      queryAll(".users-input .item:nth-of-type(1)").text(),
+      queryAll("#private-message-users .selected-name:nth-of-type(1)")
+        .text()
+        .trim(),
       "codinghorror"
     );
     assert.ok(
@@ -164,7 +166,7 @@ acceptance("Composer Actions", function (needs) {
     await composerActions.selectRowByValue("reply_as_new_group_message");
 
     const items = [];
-    queryAll(".users-input .item").each((_, item) =>
+    queryAll("#private-message-users .selected-name").each((_, item) =>
       items.push(item.textContent.trim())
     );
 
@@ -348,7 +350,9 @@ acceptance("Composer Actions", function (needs) {
     await composerActions.selectRowByValue("reply_as_private_message");
 
     assert.equal(
-      queryAll(".users-input .item:nth-of-type(1)").text(),
+      queryAll("#private-message-users .selected-name:nth-of-type(1)")
+        .text()
+        .trim(),
       "uwe_keim"
     );
     assert.ok(
diff --git a/app/assets/javascripts/discourse/tests/acceptance/composer-test.js b/app/assets/javascripts/discourse/tests/acceptance/composer-test.js
index 1514688695..993d2cf80a 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/composer-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/composer-test.js
@@ -713,7 +713,9 @@ acceptance("Composer", function (needs) {
       await click(".modal .btn-default");
 
       assert.equal(
-        queryAll(".users-input .item:nth-of-type(1)").text(),
+        queryAll("#private-message-users .selected-name:nth-of-type(1)")
+          .text()
+          .trim(),
         "codinghorror"
       );
     } finally {
diff --git a/app/assets/javascripts/discourse/tests/acceptance/group-test.js b/app/assets/javascripts/discourse/tests/acceptance/group-test.js
index 5164cd920d..2091dab9e7 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/group-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/group-test.js
@@ -215,7 +215,7 @@ acceptance("Group - Authenticated", function (needs) {
 
     assert.ok(count("#reply-control") === 1, "it opens the composer");
     assert.equal(
-      queryAll(".ac-wrap .item").text(),
+      queryAll("#private-message-users .selected-name").text().trim(),
       "discourse",
       "it prefills the group name"
     );
diff --git a/app/assets/javascripts/discourse/tests/acceptance/new-message-test.js b/app/assets/javascripts/discourse/tests/acceptance/new-message-test.js
index 764c1abd0a..b5ef162d4f 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/new-message-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/new-message-test.js
@@ -36,7 +36,9 @@ acceptance("New Message - Authenticated", function (needs) {
       "it pre-fills message body"
     );
     assert.equal(
-      queryAll(".users-input .item:nth-of-type(1)").text().trim(),
+      queryAll("#private-message-users .selected-name:nth-of-type(1)")
+        .text()
+        .trim(),
       "charlie",
       "it selects correct username"
     );
diff --git a/app/assets/javascripts/discourse/tests/acceptance/topic-test.js b/app/assets/javascripts/discourse/tests/acceptance/topic-test.js
index 29b8d6d8c2..68f80fd134 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/topic-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/topic-test.js
@@ -67,22 +67,25 @@ acceptance("Topic", function (needs) {
       "it fills composer with the ring string"
     );
 
-    const targets = queryAll(".item span", ".composer-fields");
+    const targets = queryAll(
+      "#private-message-users .selected-name",
+      ".composer-fields"
+    );
 
     assert.equal(
-      $(targets[0]).text(),
+      $(targets[0]).text().trim(),
       "someguy",
       "it fills up the composer with the right user to start the PM to"
     );
 
     assert.equal(
-      $(targets[1]).text(),
+      $(targets[1]).text().trim(),
       "test",
       "it fills up the composer with the right user to start the PM to"
     );
 
     assert.equal(
-      $(targets[2]).text(),
+      $(targets[2]).text().trim(),
       "Group",
       "it fills up the composer with the right group to start the PM to"
     );
diff --git a/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser-header.js b/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser-header.js
new file mode 100644
index 0000000000..b25bb6edef
--- /dev/null
+++ b/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser-header.js
@@ -0,0 +1,76 @@
+import MultiSelectHeaderComponent from "select-kit/components/multi-select/multi-select-header";
+import { computed } from "@ember/object";
+import { gt } from "@ember/object/computed";
+import { isTesting } from "discourse-common/config/environment";
+import layout from "select-kit/templates/components/email-group-user-chooser-header";
+
+export default MultiSelectHeaderComponent.extend({
+  layout,
+  classNames: ["email-group-user-chooser-header"],
+  hasHiddenItems: gt("hiddenItemsCount", 0),
+
+  shownItems: computed("hiddenItemsCount", function () {
+    if (
+      this.selectKit.noneItem === this.selectedContent ||
+      this.hiddenItemsCount === 0
+    ) {
+      return this.selectedContent;
+    }
+    return this.selectedContent.slice(
+      0,
+      this.selectedContent.length - this.hiddenItemsCount
+    );
+  }),
+
+  hiddenItemsCount: computed(
+    "selectedContent.[]",
+    "selectKit.options.autoWrap",
+    "selectKit.isExpanded",
+    function () {
+      if (
+        !this.selectKit.options.autoWrap ||
+        this.selectKit.isExpanded ||
+        this.selectedContent === this.selectKit.noneItem ||
+        this.selectedContent.length <= 1 ||
+        isTesting()
+      ) {
+        return 0;
+      } else {
+        const selectKitHeaderWidth = this.element.offsetWidth;
+        const choices = this.element.querySelectorAll(".selected-name.choice");
+        const input = this.element.querySelector(".filter-input");
+        const alreadyHidden = this.element.querySelector(".x-more-item");
+        if (alreadyHidden) {
+          const hiddenCount = parseInt(
+            alreadyHidden.getAttribute("data-hidden-count"),
+            10
+          );
+          return (
+            hiddenCount +
+            (this.selectedContent.length - (choices.length + hiddenCount))
+          );
+        }
+        if (choices.length === 0 && this.selectedContent.length > 0) {
+          return 0;
+        }
+        let total = choices[0].offsetWidth + input.offsetWidth;
+        let shownItemsCount = 1;
+        let shouldHide = false;
+        for (let i = 1; i < choices.length - 1; i++) {
+          const currentWidth = choices[i].offsetWidth;
+          const nextWidth = choices[i + 1].offsetWidth;
+          const ratio =
+            (total + currentWidth + nextWidth) / selectKitHeaderWidth;
+          if (ratio >= 0.95) {
+            shouldHide = true;
+            break;
+          } else {
+            shownItemsCount++;
+            total += currentWidth;
+          }
+        }
+        return shouldHide ? choices.length - shownItemsCount : 0;
+      }
+    }
+  ),
+});
diff --git a/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser-row.js b/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser-row.js
new file mode 100644
index 0000000000..5426c82fb7
--- /dev/null
+++ b/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser-row.js
@@ -0,0 +1,7 @@
+import SelectKitRowComponent from "select-kit/components/select-kit/select-kit-row";
+import layout from "select-kit/templates/components/email-group-user-chooser-row";
+
+export default SelectKitRowComponent.extend({
+  layout,
+  classNames: ["email-group-user-chooser-row"],
+});
diff --git a/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser.js b/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser.js
new file mode 100644
index 0000000000..03a940c4fd
--- /dev/null
+++ b/app/assets/javascripts/select-kit/addon/components/email-group-user-chooser.js
@@ -0,0 +1,46 @@
+import UserChooserComponent from "select-kit/components/user-chooser";
+
+export default UserChooserComponent.extend({
+  pluginApiIdentifiers: ["email-group-user-chooser"],
+  classNames: ["email-group-user-chooser"],
+  valueProperty: "id",
+  nameProperty: "name",
+
+  modifyComponentForRow() {
+    return "email-group-user-chooser-row";
+  },
+
+  selectKitOptions: {
+    headerComponent: "email-group-user-chooser-header",
+    autoWrap: false,
+  },
+
+  search() {
+    const superPromise = this._super(...arguments);
+    if (!superPromise) {
+      return;
+    }
+    return superPromise.then((results) => {
+      if (!results || results.length === 0) {
+        return;
+      }
+      return results.map((item) => {
+        const reconstructed = {};
+        if (item.username) {
+          reconstructed.id = item.username;
+          if (item.username.includes("@")) {
+            reconstructed.isEmail = true;
+          } else {
+            reconstructed.isUser = true;
+            reconstructed.name = item.name;
+          }
+        } else if (item.name) {
+          reconstructed.id = item.name;
+          reconstructed.name = item.full_name;
+          reconstructed.isGroup = true;
+        }
+        return Object.assign({}, item, reconstructed);
+      });
+    });
+  },
+});
diff --git a/app/assets/javascripts/select-kit/addon/components/select-kit.js b/app/assets/javascripts/select-kit/addon/components/select-kit.js
index 5432a60295..175a88e890 100644
--- a/app/assets/javascripts/select-kit/addon/components/select-kit.js
+++ b/app/assets/javascripts/select-kit/addon/components/select-kit.js
@@ -87,6 +87,7 @@ export default Component.extend(
           isHidden: false,
           isExpanded: false,
           isFilterExpanded: false,
+          enterDisabled: false,
           hasSelection: false,
           hasNoContent: true,
           highlighted: null,
@@ -570,64 +571,75 @@ export default Component.extend(
 
     _searchWrapper(filter) {
       this.clearErrors();
-      this.setProperties({ mainCollection: [], "selectKit.isLoading": true });
+      this.setProperties({
+        mainCollection: [],
+        "selectKit.isLoading": true,
+        "selectKit.enterDisabled": true,
+      });
       this._safeAfterRender(() => this.popper && this.popper.update());
 
       let content = [];
 
-      return Promise.resolve(this.search(filter)).then((result) => {
-        content = content.concat(makeArray(result));
-        content = this.selectKit.modifyContent(content).filter(Boolean);
+      return Promise.resolve(this.search(filter))
+        .then((result) => {
+          content = content.concat(makeArray(result));
+          content = this.selectKit.modifyContent(content).filter(Boolean);
 
-        if (this.selectKit.valueProperty) {
-          content = content.uniqBy(this.selectKit.valueProperty);
-        } else {
-          content = content.uniq();
-        }
-
-        if (this.selectKit.options.limitMatches) {
-          content = content.slice(0, this.selectKit.options.limitMatches);
-        }
-
-        const noneItem = this.selectKit.noneItem;
-        if (
-          this.selectKit.options.allowAny &&
-          filter &&
-          this.getName(noneItem) !== filter
-        ) {
-          filter = this.createContentFromInput(filter);
-          if (this.validateCreate(filter, content)) {
-            this.selectKit.set("newItem", this.defaultItem(filter, filter));
-            content.unshift(this.selectKit.newItem);
+          if (this.selectKit.valueProperty) {
+            content = content.uniqBy(this.selectKit.valueProperty);
+          } else {
+            content = content.uniq();
           }
-        }
 
-        const hasNoContent = isEmpty(content);
+          if (this.selectKit.options.limitMatches) {
+            content = content.slice(0, this.selectKit.options.limitMatches);
+          }
 
-        if (
-          this.selectKit.hasSelection &&
-          noneItem &&
-          this.selectKit.options.autoInsertNoneItem
-        ) {
-          content.unshift(noneItem);
-        }
+          const noneItem = this.selectKit.noneItem;
+          if (
+            this.selectKit.options.allowAny &&
+            filter &&
+            this.getName(noneItem) !== filter
+          ) {
+            filter = this.createContentFromInput(filter);
+            if (this.validateCreate(filter, content)) {
+              this.selectKit.set("newItem", this.defaultItem(filter, filter));
+              content.unshift(this.selectKit.newItem);
+            }
+          }
 
-        this.set("mainCollection", content);
+          const hasNoContent = isEmpty(content);
 
-        this.selectKit.setProperties({
-          highlighted:
-            this.singleSelect && this.value
-              ? this.itemForValue(this.value, this.mainCollection)
-              : this.mainCollection.firstObject,
-          isLoading: false,
-          hasNoContent,
+          if (
+            this.selectKit.hasSelection &&
+            noneItem &&
+            this.selectKit.options.autoInsertNoneItem
+          ) {
+            content.unshift(noneItem);
+          }
+
+          this.set("mainCollection", content);
+
+          this.selectKit.setProperties({
+            highlighted:
+              this.singleSelect && this.value
+                ? this.itemForValue(this.value, this.mainCollection)
+                : this.mainCollection.firstObject,
+            isLoading: false,
+            hasNoContent,
+          });
+
+          this._safeAfterRender(() => {
+            this.popper && this.popper.update();
+            this._focusFilter();
+          });
+        })
+        .finally(() => {
+          if (this.isDestroyed || this.isDestroying) {
+            return;
+          }
+          this.set("selectKit.enterDisabled", false);
         });
-
-        this._safeAfterRender(() => {
-          this.popper && this.popper.update();
-          this._focusFilter();
-        });
-      });
     },
 
     _safeAfterRender(fn) {
@@ -854,11 +866,12 @@ export default Component.extend(
                   }
 
                   const popperElement = data.state.elements.popper;
-                  if (
+                  const topPlacement =
                     popperElement &&
-                    popperElement.getAttribute("data-popper-placement") ===
-                      "top-start"
-                  ) {
+                    popperElement
+                      .getAttribute("data-popper-placement")
+                      .startsWith("top-");
+                  if (topPlacement) {
                     this.element.classList.remove("is-under");
                     this.element.classList.add("is-above");
                   } else {
@@ -868,6 +881,20 @@ export default Component.extend(
 
                   wrapper.style.width = `${this.element.offsetWidth}px`;
                   wrapper.style.height = `${height}px`;
+                  if (placementStrategy === "fixed") {
+                    const rects = this.element.getClientRects()[0];
+                    const bodyRects = body && body.getClientRects()[0];
+                    wrapper.style.position = "fixed";
+                    wrapper.style.left = `${rects.left}px`;
+                    if (topPlacement && bodyRects) {
+                      wrapper.style.top = `${rects.top - bodyRects.height}px`;
+                    } else {
+                      wrapper.style.top = `${rects.top}px`;
+                    }
+                    if (isDocumentRTL()) {
+                      wrapper.style.right = "unset";
+                    }
+                  }
                 }
               },
             },
diff --git a/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-filter.js b/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-filter.js
index 5224dcb2fd..9135a95fff 100644
--- a/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-filter.js
+++ b/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-filter.js
@@ -56,6 +56,16 @@ export default Component.extend(UtilsMixin, {
       return true;
     },
 
+    onKeyup(event) {
+      if (event.keyCode === 13 && this.selectKit.enterDisabled) {
+        this.element.querySelector("input").focus();
+        event.preventDefault();
+        event.stopPropagation();
+        return false;
+      }
+      return true;
+    },
+
     onKeydown(event) {
       if (!this.selectKit.onKeydown(event)) {
         return false;
@@ -93,8 +103,15 @@ export default Component.extend(UtilsMixin, {
         return false;
       }
 
-      if (event.keyCode === 13 && !this.selectKit.highlighted) {
+      if (
+        event.keyCode === 13 &&
+        (!this.selectKit.highlighted || this.selectKit.enterDisabled)
+      ) {
         this.element.querySelector("input").focus();
+        if (this.selectKit.enterDisabled) {
+          event.preventDefault();
+          event.stopPropagation();
+        }
         return false;
       }
 
@@ -109,6 +126,7 @@ export default Component.extend(UtilsMixin, {
         this.selectKit.close(event);
         return;
       }
+      this.selectKit.set("highlighted", null);
     },
   },
 });
diff --git a/app/assets/javascripts/select-kit/addon/components/user-chooser.js b/app/assets/javascripts/select-kit/addon/components/user-chooser.js
index 6bf7257bad..a98fb559fd 100644
--- a/app/assets/javascripts/select-kit/addon/components/user-chooser.js
+++ b/app/assets/javascripts/select-kit/addon/components/user-chooser.js
@@ -24,6 +24,7 @@ export default MultiSelectComponent.extend({
     includeMessageableGroups: false,
     allowEmails: false,
     groupMembersOf: undefined,
+    excludeCurrentUser: false,
   },
 
   content: computed("value.[]", function () {
diff --git a/app/assets/javascripts/select-kit/addon/templates/components/email-group-user-chooser-header.hbs b/app/assets/javascripts/select-kit/addon/templates/components/email-group-user-chooser-header.hbs
new file mode 100644
index 0000000000..4d5f6a2f68
--- /dev/null
+++ b/app/assets/javascripts/select-kit/addon/templates/components/email-group-user-chooser-header.hbs
@@ -0,0 +1,22 @@
+<div class="choices">
+  {{#each shownItems as |item|}}
+    {{component selectKit.options.selectedNameComponent
+      tabindex=tabindex
+      item=item
+      selectKit=selectKit
+    }}
+  {{/each}}
+  {{#if hasHiddenItems}}
+    <div class="x-more-item" data-hidden-count={{hiddenItemsCount}}>
+      {{i18n "x_more" count=hiddenItemsCount}}
+    </div>
+  {{/if}}
+
+  {{#unless hasReachedMaximumSelection}}
+    <div class="choice input-wrapper">
+      {{component selectKit.options.filterComponent
+        selectKit=selectKit
+      }}
+    </div>
+  {{/unless}}
+</div>
diff --git a/app/assets/javascripts/select-kit/addon/templates/components/email-group-user-chooser-row.hbs b/app/assets/javascripts/select-kit/addon/templates/components/email-group-user-chooser-row.hbs
new file mode 100644
index 0000000000..4169de194c
--- /dev/null
+++ b/app/assets/javascripts/select-kit/addon/templates/components/email-group-user-chooser-row.hbs
@@ -0,0 +1,12 @@
+{{#if item.isUser}}
+  {{avatar item imageSize="tiny"}}
+  <span class="identifier">{{format-username item.id}}</span>
+  <span class="name">{{item.name}}</span>
+{{else if item.isGroup}}
+  {{d-icon "users"}}
+  <span class="identifier">{{item.id}}</span>
+  <span class="name">{{item.full_name}}</span>
+{{else}}
+  {{d-icon "envelope"}}
+  <span class="identifier">{{item.id}}</span>
+{{/if}}
diff --git a/app/assets/javascripts/select-kit/addon/templates/components/select-kit/select-kit-filter.hbs b/app/assets/javascripts/select-kit/addon/templates/components/select-kit/select-kit-filter.hbs
index d50302e7b2..57e1d3efcf 100644
--- a/app/assets/javascripts/select-kit/addon/templates/components/select-kit/select-kit-filter.hbs
+++ b/app/assets/javascripts/select-kit/addon/templates/components/select-kit/select-kit-filter.hbs
@@ -11,6 +11,7 @@
     input=(action "onInput")
     paste=(action "onPaste")
     keyDown=(action "onKeydown")
+    keyUp=(action "onKeyup")
   }}
 
   {{#if selectKit.options.filterIcon}}
diff --git a/app/assets/stylesheets/common/admin/api.scss b/app/assets/stylesheets/common/admin/api.scss
index 3ba34a2972..b7e19b6665 100644
--- a/app/assets/stylesheets/common/admin/api.scss
+++ b/app/assets/stylesheets/common/admin/api.scss
@@ -100,7 +100,8 @@ table.api-keys {
 
         .value-list,
         .select-kit,
-        input[type="text"] {
+        input[type="text"],
+        input[type="text"].filter-input {
           width: 100%;
           margin: 0;
         }
diff --git a/app/assets/stylesheets/common/select-kit/_index.scss b/app/assets/stylesheets/common/select-kit/_index.scss
index 21219bdcb8..26789b351c 100644
--- a/app/assets/stylesheets/common/select-kit/_index.scss
+++ b/app/assets/stylesheets/common/select-kit/_index.scss
@@ -7,6 +7,7 @@
 @import "combo-box";
 @import "composer-actions";
 @import "dropdown-select-box";
+@import "email-group-user-chooser";
 @import "future-date-input-selector";
 @import "icon-picker";
 @import "list-setting";
diff --git a/app/assets/stylesheets/common/select-kit/email-group-user-chooser.scss b/app/assets/stylesheets/common/select-kit/email-group-user-chooser.scss
new file mode 100644
index 0000000000..4b136c1750
--- /dev/null
+++ b/app/assets/stylesheets/common/select-kit/email-group-user-chooser.scss
@@ -0,0 +1,37 @@
+.select-kit.email-group-user-chooser {
+  .select-kit-row.email-group-user-chooser-row {
+    .identifier {
+      color: var(--primary);
+      white-space: nowrap;
+    }
+    .name {
+      color: var(--primary-high);
+      font-size: $font-down-1;
+      margin-left: 0.5em;
+      overflow: hidden;
+      white-space: nowrap;
+      text-overflow: ellipsis;
+    }
+    .avatar,
+    .d-icon {
+      margin-left: 0;
+      margin-right: 0.5em;
+    }
+  }
+  .select-kit-header {
+    .x-more-item {
+      background: var(--primary-low);
+      padding: 0.25em;
+      flex: 1;
+      align-items: center;
+      display: flex;
+      justify-content: space-between;
+      box-sizing: border-box;
+      margin: 2px 0 0px 3px;
+      float: left;
+      height: 30px;
+      color: inherit;
+      outline: none;
+    }
+  }
+}
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 15057877a7..65a8c55f8e 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -245,6 +245,9 @@ en:
     now: "just now"
     read_more: "read more"
     more: "More"
+    x_more:
+      one: "%{count} More"
+      other: "%{count} More"
     less: "Less"
     never: "never"
     every_30_minutes: "every 30 minutes"