diff --git a/lib/shared/message-utils.js b/lib/shared/message-utils.js
index 03cb22a11..8d6419b90 100644
--- a/lib/shared/message-utils.js
+++ b/lib/shared/message-utils.js
@@ -1,531 +1,546 @@
 // @flow
 
 import invariant from 'invariant';
 import _maxBy from 'lodash/fp/maxBy';
 import _orderBy from 'lodash/fp/orderBy';
+import * as React from 'react';
 
 import { useStringForUser } from '../hooks/ens-cache';
 import { userIDsToRelativeUserInfos } from '../selectors/user-selectors';
 import type { PlatformDetails } from '../types/device-types';
 import type { Media } from '../types/media-types';
 import {
   type MessageInfo,
   type RawMessageInfo,
   type RobotextMessageInfo,
   type RawMultimediaMessageInfo,
   type MessageData,
   type MessageTruncationStatus,
   type MultimediaMessageData,
   type MessageStore,
   type ComposableMessageInfo,
   messageTypes,
   messageTruncationStatus,
   type RawComposableMessageInfo,
   type ThreadMessageInfo,
 } from '../types/message-types';
 import type { ImagesMessageData } from '../types/messages/images';
 import type { MediaMessageData } from '../types/messages/media';
 import type {
   RawReactionMessageInfo,
   ReactionMessageInfo,
 } from '../types/messages/reaction';
 import { type ThreadInfo } from '../types/thread-types';
 import type { UserInfos } from '../types/user-types';
 import { type EntityText, entityTextToRawString } from '../utils/entity-text';
 import { codeBlockRegex, type ParserRules } from './markdown';
 import { messageSpecs } from './messages/message-specs';
 import { threadIsGroupChat } from './thread-utils';
 
 const localIDPrefix = 'local';
 
 // Prefers localID
 function messageKey(messageInfo: MessageInfo | RawMessageInfo): string {
   if (messageInfo.localID) {
     return messageInfo.localID;
   }
   invariant(messageInfo.id, 'localID should exist if ID does not');
   return messageInfo.id;
 }
 
 // Prefers serverID
 function messageID(messageInfo: MessageInfo | RawMessageInfo): string {
   if (messageInfo.id) {
     return messageInfo.id;
   }
   invariant(messageInfo.localID, 'localID should exist if ID does not');
   return messageInfo.localID;
 }
 
 function robotextForMessageInfo(
   messageInfo: RobotextMessageInfo,
   threadInfo: ?ThreadInfo,
 ): EntityText {
   const messageSpec = messageSpecs[messageInfo.type];
   invariant(
     messageSpec.robotext,
     `we're not aware of messageType ${messageInfo.type}`,
   );
   return messageSpec.robotext(messageInfo, { threadInfo });
 }
 
 function createMessageInfo(
   rawMessageInfo: RawMessageInfo,
   viewerID: ?string,
   userInfos: UserInfos,
   threadInfos: { +[id: string]: ThreadInfo },
 ): ?MessageInfo {
   const creatorInfo = userInfos[rawMessageInfo.creatorID];
   const creator = {
     id: rawMessageInfo.creatorID,
     username: creatorInfo ? creatorInfo.username : 'anonymous',
     isViewer: rawMessageInfo.creatorID === viewerID,
   };
 
   const createRelativeUserInfos = (userIDs: $ReadOnlyArray<string>) =>
     userIDsToRelativeUserInfos(userIDs, viewerID, userInfos);
   const createMessageInfoFromRaw = (rawInfo: RawMessageInfo) =>
     createMessageInfo(rawInfo, viewerID, userInfos, threadInfos);
 
   const messageSpec = messageSpecs[rawMessageInfo.type];
 
   return messageSpec.createMessageInfo(rawMessageInfo, creator, {
     threadInfos,
     createMessageInfoFromRaw,
     createRelativeUserInfos,
   });
 }
 
 type LengthResult = {
   +local: number,
   +realized: number,
 };
 function findMessageIDMaxLengths(
   messageIDs: $ReadOnlyArray<?string>,
 ): LengthResult {
   const result = {
     local: 0,
     realized: 0,
   };
   for (const id of messageIDs) {
     if (!id) {
       continue;
     }
     if (id.startsWith(localIDPrefix)) {
       result.local = Math.max(result.local, id.length - localIDPrefix.length);
     } else {
       result.realized = Math.max(result.realized, id.length);
     }
   }
   return result;
 }
 
 function extendMessageID(id: ?string, lengths: LengthResult): ?string {
   if (!id) {
     return id;
   }
   if (id.startsWith(localIDPrefix)) {
     const zeroPaddedID = id
       .substr(localIDPrefix.length)
       .padStart(lengths.local, '0');
     return `${localIDPrefix}${zeroPaddedID}`;
   }
   return id.padStart(lengths.realized, '0');
 }
 
 function sortMessageInfoList<T: MessageInfo | RawMessageInfo>(
   messageInfos: $ReadOnlyArray<T>,
 ): T[] {
   const lengths = findMessageIDMaxLengths(
     messageInfos.map(message => message?.id),
   );
   return _orderBy([
     'time',
     (message: T) => extendMessageID(message?.id, lengths),
   ])(['desc', 'desc'])(messageInfos);
 }
 
 const sortMessageIDs: (messages: { +[id: string]: RawMessageInfo }) => (
   messageIDs: $ReadOnlyArray<string>,
 ) => string[] = messages => messageIDs => {
   const lengths = findMessageIDMaxLengths(messageIDs);
   return _orderBy([
     (id: string) => messages[id].time,
     (id: string) => extendMessageID(id, lengths),
   ])(['desc', 'desc'])(messageIDs);
 };
 
 function rawMessageInfoFromMessageData(
   messageData: MessageData,
   id: ?string,
 ): RawMessageInfo {
   const messageSpec = messageSpecs[messageData.type];
   invariant(
     messageSpec.rawMessageInfoFromMessageData,
     `we're not aware of messageType ${messageData.type}`,
   );
   return messageSpec.rawMessageInfoFromMessageData(messageData, id);
 }
 
 function mostRecentMessageTimestamp(
   messageInfos: $ReadOnlyArray<RawMessageInfo>,
   previousTimestamp: number,
 ): number {
   if (messageInfos.length === 0) {
     return previousTimestamp;
   }
   return _maxBy('time')(messageInfos).time;
 }
 
 function usersInMessageInfos(
   messageInfos: $ReadOnlyArray<MessageInfo | RawMessageInfo>,
 ): string[] {
   const userIDs = new Set();
   for (const messageInfo of messageInfos) {
     if (messageInfo.creatorID) {
       userIDs.add(messageInfo.creatorID);
     } else if (messageInfo.creator) {
       userIDs.add(messageInfo.creator.id);
     }
   }
   return [...userIDs];
 }
 
 function combineTruncationStatuses(
   first: MessageTruncationStatus,
   second: ?MessageTruncationStatus,
 ): MessageTruncationStatus {
   if (
     first === messageTruncationStatus.EXHAUSTIVE ||
     second === messageTruncationStatus.EXHAUSTIVE
   ) {
     return messageTruncationStatus.EXHAUSTIVE;
   } else if (
     first === messageTruncationStatus.UNCHANGED &&
     second !== null &&
     second !== undefined
   ) {
     return second;
   } else {
     return first;
   }
 }
 
 function shimUnsupportedRawMessageInfos(
   rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   platformDetails: ?PlatformDetails,
 ): RawMessageInfo[] {
   if (platformDetails && platformDetails.platform === 'web') {
     return [...rawMessageInfos];
   }
   return rawMessageInfos.map(rawMessageInfo => {
     const { shimUnsupportedMessageInfo } = messageSpecs[rawMessageInfo.type];
     if (shimUnsupportedMessageInfo) {
       return shimUnsupportedMessageInfo(rawMessageInfo, platformDetails);
     }
     return rawMessageInfo;
   });
 }
 
 type MediaMessageDataCreationInput = $ReadOnly<{
   threadID: string,
   creatorID: string,
   media: $ReadOnlyArray<Media>,
   localID?: ?string,
   time?: ?number,
   ...
 }>;
 function createMediaMessageData(
   input: MediaMessageDataCreationInput,
 ): MultimediaMessageData {
   let allMediaArePhotos = true;
   const photoMedia = [];
   for (const singleMedia of input.media) {
     if (singleMedia.type === 'video') {
       allMediaArePhotos = false;
       break;
     } else {
       photoMedia.push(singleMedia);
     }
   }
 
   const { localID, threadID, creatorID } = input;
   const time = input.time ? input.time : Date.now();
   let messageData;
   if (allMediaArePhotos) {
     messageData = ({
       type: messageTypes.IMAGES,
       threadID,
       creatorID,
       time,
       media: photoMedia,
     }: ImagesMessageData);
   } else {
     messageData = ({
       type: messageTypes.MULTIMEDIA,
       threadID,
       creatorID,
       time,
       media: input.media,
     }: MediaMessageData);
   }
   if (localID) {
     messageData.localID = localID;
   }
   return messageData;
 }
 
 type MediaMessageInfoCreationInput = $ReadOnly<{
   ...$Exact<MediaMessageDataCreationInput>,
   id?: ?string,
 }>;
 function createMediaMessageInfo(
   input: MediaMessageInfoCreationInput,
 ): RawMultimediaMessageInfo {
   const messageData = createMediaMessageData(input);
   const createRawMessageInfo =
     messageSpecs[messageData.type].rawMessageInfoFromMessageData;
   invariant(
     createRawMessageInfo,
     'multimedia message spec should have rawMessageInfoFromMessageData',
   );
   const result = createRawMessageInfo(messageData, input.id);
   invariant(
     result.type === messageTypes.MULTIMEDIA ||
       result.type === messageTypes.IMAGES,
     `media messageSpec returned MessageType ${result.type}`,
   );
   return result;
 }
 
 function stripLocalID(
   rawMessageInfo: RawComposableMessageInfo | RawReactionMessageInfo,
 ) {
   const { localID, ...rest } = rawMessageInfo;
   return rest;
 }
 
 function stripLocalIDs(
   input: $ReadOnlyArray<RawMessageInfo>,
 ): RawMessageInfo[] {
   const output = [];
   for (const rawMessageInfo of input) {
     if (rawMessageInfo.localID) {
       invariant(
         rawMessageInfo.id,
         'serverID should be set if localID is being stripped',
       );
       output.push(stripLocalID(rawMessageInfo));
     } else {
       output.push(rawMessageInfo);
     }
   }
   return output;
 }
 
 // Normally we call trim() to remove whitespace at the beginning and end of each
 // message. However, our Markdown parser supports a "codeBlock" format where the
 // user can indent each line to indicate a code block. If we match the
 // corresponding RegEx, we'll only trim whitespace off the end.
 function trimMessage(message: string): string {
   message = message.replace(/^\n*/, '');
   return codeBlockRegex.exec(message) ? message.trimEnd() : message.trim();
 }
 
 function createMessageQuote(message: string): string {
   // add `>` to each line to include empty lines in the quote
   return message.replace(/^/gm, '> ');
 }
 
 function createMessageReply(message: string): string {
   return createMessageQuote(message) + '\n\n';
 }
 
 function getMostRecentNonLocalMessageID(
   threadID: string,
   messageStore: MessageStore,
 ): ?string {
   const thread = messageStore.threads[threadID];
   return thread?.messageIDs.find(id => !id.startsWith(localIDPrefix));
 }
 
 export type GetMessageTitleViewerContext =
   | 'global_viewer'
   | 'individual_viewer';
 
 function getMessageTitle(
   messageInfo:
     | ComposableMessageInfo
     | RobotextMessageInfo
     | ReactionMessageInfo,
   threadInfo: ThreadInfo,
   markdownRules: ParserRules,
   viewerContext?: GetMessageTitleViewerContext = 'individual_viewer',
 ): string {
   let entityText;
   const { messageTitle } = messageSpecs[messageInfo.type];
   if (!messageTitle) {
     invariant(
       messageInfo.type !== messageTypes.TEXT &&
         messageInfo.type !== messageTypes.IMAGES &&
         messageInfo.type !== messageTypes.MULTIMEDIA &&
         messageInfo.type !== messageTypes.REACTION,
       'messageTitle can only be auto-generated for RobotextMessageInfo',
     );
     entityText = robotextForMessageInfo(messageInfo, threadInfo);
   } else {
     entityText = messageTitle({ messageInfo, threadInfo, markdownRules });
   }
   return entityTextToRawString(entityText, {
     threadID: threadInfo.id,
     ignoreViewer: viewerContext === 'global_viewer',
   });
 }
 
 function mergeThreadMessageInfos(
   first: ThreadMessageInfo,
   second: ThreadMessageInfo,
   messages: { +[id: string]: RawMessageInfo },
 ): ThreadMessageInfo {
   let firstPointer = 0;
   let secondPointer = 0;
   const mergedMessageIDs = [];
   let firstCandidate = first.messageIDs[firstPointer];
   let secondCandidate = second.messageIDs[secondPointer];
   while (firstCandidate !== undefined || secondCandidate !== undefined) {
     if (firstCandidate === undefined) {
       mergedMessageIDs.push(secondCandidate);
       secondPointer++;
     } else if (secondCandidate === undefined) {
       mergedMessageIDs.push(firstCandidate);
       firstPointer++;
     } else if (firstCandidate === secondCandidate) {
       mergedMessageIDs.push(firstCandidate);
       firstPointer++;
       secondPointer++;
     } else {
       const firstMessage = messages[firstCandidate];
       const secondMessage = messages[secondCandidate];
       invariant(
         firstMessage && secondMessage,
         'message in messageIDs not present in MessageStore',
       );
       if (
         (firstMessage.id &&
           secondMessage.id &&
           firstMessage.id === secondMessage.id) ||
         (firstMessage.localID &&
           secondMessage.localID &&
           firstMessage.localID === secondMessage.localID)
       ) {
         mergedMessageIDs.push(firstCandidate);
         firstPointer++;
         secondPointer++;
       } else if (firstMessage.time < secondMessage.time) {
         mergedMessageIDs.push(secondCandidate);
         secondPointer++;
       } else {
         mergedMessageIDs.push(firstCandidate);
         firstPointer++;
       }
     }
     firstCandidate = first.messageIDs[firstPointer];
     secondCandidate = second.messageIDs[secondPointer];
   }
   return {
     messageIDs: mergedMessageIDs,
     startReached: first.startReached && second.startReached,
     lastNavigatedTo: Math.max(first.lastNavigatedTo, second.lastNavigatedTo),
     lastPruned: Math.max(first.lastPruned, second.lastPruned),
   };
 }
 
 type MessagePreviewPart = {
   +text: string,
   // unread has highest contrast, followed by primary, followed by secondary
   +style: 'unread' | 'primary' | 'secondary',
 };
 type MessagePreviewResult = {
   +message: MessagePreviewPart,
   +username: ?MessagePreviewPart,
 };
 function useMessagePreview(
   originalMessageInfo: ?MessageInfo,
   threadInfo: ThreadInfo,
   markdownRules: ParserRules,
 ): ?MessagePreviewResult {
   let messageInfo;
   if (
     originalMessageInfo &&
     originalMessageInfo.type === messageTypes.SIDEBAR_SOURCE
   ) {
     messageInfo = originalMessageInfo.sourceMessage;
   } else {
     messageInfo = originalMessageInfo;
   }
 
   const hasUsername =
     threadIsGroupChat(threadInfo) ||
     threadInfo.name !== '' ||
     messageInfo?.creator.isViewer;
+  const shouldDisplayUser =
+    messageInfo?.type === messageTypes.TEXT && hasUsername;
 
   const stringForUser = useStringForUser(
-    messageInfo?.type === messageTypes.TEXT && hasUsername
-      ? messageInfo?.creator
-      : null,
+    shouldDisplayUser ? messageInfo?.creator : null,
   );
-  if (!messageInfo) {
-    return messageInfo;
-  }
 
-  let username = null;
-  if (messageInfo.type === messageTypes.TEXT && hasUsername) {
+  const { unread } = threadInfo.currentUser;
+  const username = React.useMemo(() => {
+    if (!shouldDisplayUser) {
+      return null;
+    }
     invariant(
       stringForUser,
       'useStringForUser should only return falsey if pass null or undefined',
     );
-    username = {
+    return {
       text: stringForUser,
-      style: 'secondary',
+      style: unread ? 'unread' : 'secondary',
     };
-  }
+  }, [shouldDisplayUser, stringForUser, unread]);
 
-  const messageTitle = getMessageTitle(messageInfo, threadInfo, markdownRules);
-  const message = {
-    text: messageTitle,
-    style: messageInfo.type === messageTypes.TEXT ? 'primary' : 'secondary',
-  };
+  const message = React.useMemo(() => {
+    if (!messageInfo) {
+      return messageInfo;
+    }
+    const messageTitle = getMessageTitle(
+      messageInfo,
+      threadInfo,
+      markdownRules,
+    );
 
-  if (threadInfo.currentUser.unread) {
-    message.style = 'unread';
-    if (username) {
-      username.style = 'unread';
+    let style;
+    if (unread) {
+      style = 'unread';
+    } else if (messageInfo.type === messageTypes.TEXT) {
+      style = 'primary';
+    } else {
+      style = 'secondary';
     }
-  }
 
-  return { message, username };
+    return { text: messageTitle, style };
+  }, [messageInfo, threadInfo, markdownRules, unread]);
+
+  return React.useMemo(() => {
+    if (!message) {
+      return message;
+    }
+    return { message, username };
+  }, [message, username]);
 }
 
 export {
   localIDPrefix,
   messageKey,
   messageID,
   robotextForMessageInfo,
   createMessageInfo,
   sortMessageInfoList,
   sortMessageIDs,
   rawMessageInfoFromMessageData,
   mostRecentMessageTimestamp,
   usersInMessageInfos,
   combineTruncationStatuses,
   shimUnsupportedRawMessageInfos,
   createMediaMessageData,
   createMediaMessageInfo,
   stripLocalIDs,
   trimMessage,
   createMessageQuote,
   createMessageReply,
   getMostRecentNonLocalMessageID,
   getMessageTitle,
   mergeThreadMessageInfos,
   useMessagePreview,
 };