How to mark all messages as read in Slack on Mac: Unreads view for 2026

Start in the Unreads view

The Mark All button lives inside Unreads, not in a menu. Unreads is the list of conversations that have new messages for you. You can open it in two ways. Click Unreads at the top of the sidebar, or press ⌘ Shift A while Slack is the front app. Both take you to the same view.

Sorting and filtering are desktop-only, according to Slack's help article. If you use Slack in a browser, the Unreads view may not match these steps. Stay in the Mac app for this task, and the screen you see will line up with the instructions here.

Mark all, then check what stayed behind

Clicking Mark All Messages Read clears the unread state across the list. It changes what Slack shows as read. It does not delete messages or channels. You can still open any conversation afterward and read it in full.

Slack's help article offers Undo on desktop if you act too quickly. Treat that window as short. Read the list first, then click. A quick scan costs far less time than an undo, and it stops you from clearing a thread you still need to answer.

Mark one conversation instead of everything

Slack's article also offers Mark as Read for a single conversation. Use it when one thread matters and the rest does not. Open the conversation from Unreads, then look for the Mark as Read option. The important thread stays unread until you handle it.

Option plus click works in the other direction. Option Click marks a message as unread again. That helps when you read a message too fast and still owe a reply. Hold ⌥ and click the message, and it returns to unread.

Say a manager's thread sits in the list next to several channel updates. Open the manager's thread first and reply. Then go back to Unreads and mark everything else as read. This order keeps the important thread from getting cleared before you touch it.

Keyboard shortcuts that save clicks

Shortcuts help when your hands are already on the keyboard. Slack's keyboard article lists the ones below for Mac. Ctrl 3 opens Activity on Mac. On Windows and Linux, the same action is Ctrl Shift 3, so people who switch between machines often press the wrong combination.

• ⌘ Shift A opens Unreads.
• Ctrl 3 opens Activity.
• Esc marks a group of messages as read, but only when you are not typing a message and no menus are open.
• Option Click marks a message as unread again.
• R marks an Activity item as read.

Esc is the one that surprises people. If your cursor is in the message box, Esc will not mark anything as read. Click somewhere neutral, close any open menu, and try again. The rule is simple once you see it.

Slack mark all as read shortcut: what the other sites say

Search results for this topic often list ⇧Esc as the Mac shortcut to mark everything as read. Keyshortcut.com describes it as covering every conversation, and it says the shortcut removes bold text from the sidebar. That site names no dialog and no version, so treat the claim as something to test, not a fact from Slack.

One third-party test ran in the Slack web app on October 3, 2026. It reported a confirm dialog titled “Clear all unreads?” with Cancel and “Yes, Clear All!” buttons. The same test saw no Undo afterward. It also found that Esc did nothing in Unreads until the first conversation was clicked. The Mac dialog text has not been checked.

Slack's own help does not mention ⇧Esc. Use the Unreads button when you want the documented route, with its Undo window. Try ⇧Esc only when you have read the confirm box, and you are sure this workspace is the one you want to clear.

What the time figures do and do not tell you

The only verified time figure in this research is about email, not Slack. A survey Slack commissioned from OnePoll covered 8,000 small-business respondents in the US and UK. It found employees spend almost 11 hours a week writing emails. That result says nothing about how long unread messages take to work through.

No verified figure for time lost to unread Slack messages turned up, so this page does not offer one. The practical question is simpler. Does the list still show things you need to answer? If yes, read before you clear.

Why the Slack red dot stays on Mac after you clear everything

A badge is a count of things that still need your attention. Clearing Unreads does not clear every one of them. Some items live outside the Unreads list, so the badge stays. These are the usual places to check.

• Unread thread replies, which can sit in Threads
• @mentions in muted channels
• Due reminders
• Other workspaces you belong to
• A collapsed sidebar section that hides unread items
• A stale Dock badge that did not refresh

Check Threads, Activity, and To-dos before you assume a badge is wrong. Open Activity with Ctrl 3. Find To-dos in the app. Slack renamed Later to To-dos in October 2026, so older guides may still say Later. The item you missed is usually in one of those three places.

Third-party fixes when nothing else works

The fixes in this section come from third-party troubleshooting guides, not from Slack's help center. Try them only after the simpler checks above did not work. Read each step before you run it, especially the Terminal command.

1. Press ⌘R to reload the Slack window.
2. Open Help > Troubleshooting > Clear Cache and Restart. Slack restarts with its cache cleared.
3. Quit Slack, then run killall Dock in Terminal. The Dock restarts, and open apps stay open.

Run killall Dock only when the Dock badge is the problem. It refreshes the Dock, and nothing else. Do not run it to fix a sidebar count, because that count lives inside Slack.

Check your Slack version and release notes

Slack's Mac release notes list the builds you can compare against. The late October and early November 2026 entries include 4.53.269 on Oct 26, 4.53.276 on Oct 29, and 4.53.280 on Nov 3, 2026, a security release. None of those entries mention unreads, shortcuts, or menus.

The unread-related fixes in the release notes are from 2018 and 2019. So these steps should match current builds of the Mac app. If your menu looks different, check your version under the Slack menu, then About Slack, and compare it with the release list.

Common mistakes people make

• Looking for Mark All in the sidebar. It lives in the Unreads view, at the bottom of the list.
• Pressing Esc while the cursor sits in the message box, then wondering why nothing changed.
• Trusting a shortcut from a random list without checking Slack's help first.
• Using Ctrl Shift 3 on Mac. On Mac, Activity is Ctrl 3.
• Clearing everything before checking Threads and To-dos for replies you still owe.
• Assuming a badge is broken when another workspace still has unread items.

Get Lazur to point at the Unreads button

Lazur is a voice assistant for the Mac. Hold ⌥ ⌘, which is Option and Command, to ask about anything on your screen. Lazur answers out loud. It listens and looks at the screen only while you hold the shortcut.

Ask where something is, and Lazur draws a circle and a label around it. Ask how to do something, and Lazur guides you one click at a time. It waits for each click before it names the next control. Lazur does not click buttons for you.

Audio and the screenshot go to AI providers to answer your question. They are not stored, and content is never used to train AI models. Lazur has a 3-day Pro trial with no credit card. The trial starts when you first open the app. Plans are on the pricing page.

A simple routine for busy Slack days

Start your day with Unreads. Read the threads that need a reply, and mark the ones you handled as read. Then use Mark All Messages Read for the rest. Check Threads and To-dos once before you clear the list, so no reply gets lost.

Finish your day in a different order. Open Activity with Ctrl 3 and look at mentions first. Then go back to Unreads and clear what is left. Reading mentions before the bulk clear means you do not miss one buried in a long list.

If you spend much of the day in Slack, the Lazur Slack page covers catching up on threads and drafting replies. The steps on this page work without it. Lazur only adds a voice guide on top.