Slack Green ブログ

Every Slack canvas already has a table of contents: hover the short lines at the left edge and a list of all headings opens. For a contents list inside the canvas, copy a link to each heading and paste them as a list. We tested both on October 28, 2026.

Slack shows a normal message in full, however long it is: a 40-line message and a 3,900-character message both showed with no Show more link in our October 28, 2026 test. Show more appears only on legacy attachments from apps, at 6 lines or about 700 characters.

Slack's Forward dialog sends a message to one channel at a time; after the first channel it offers no second one. To post the same message to several channels, forward it once per channel or use a short API script. We tested both on October 28, 2026.

You can change the image in a Slack message you already sent: open Edit message, remove the old image with its X, add a new one with the + button, and save. We tested every step in the Slack web app on October 28, 2026, including adding an image to a text-only message.

Workspace owners and admins turn off join and leave messages in Settings & permissions, Channel Join & Leave Messages. It works on the Free plan. We switched it on and off on October 28, 2026: with it off, leaves posted nothing, but joins in a small channel still showed.

Slack has no mute button for a person across all of Slack. You can mute your DM with them, which stops notifications but still shows a number badge, or use Hide person. We muted a DM and tested what still came through on October 28, 2026.

To stop huddles in one channel, open the channel's Settings and set Huddles to No. To stop huddle alerts for yourself, untick New huddles in Preferences > Notifications. We tested both in a Free workspace on October 28, 2026.

Slack has no button to edit or clear Frequently Used emoji; the list follows what you pick. You can set the three one-click reactions in Preferences > Messages & media. We tested both on October 28, 2026.

Every Slack canvas keeps a version history, even on the Free plan. Open the canvas menu, choose View version history, pick a version and click Restore this version. We edited a canvas three times and restored the first version on October 28, 2026.

In the Slack web app, a thread opens in the side panel. Its menu offers Open in split view, which keeps the thread on screen while you move to other channels. We tested every option on October 28, 2026.

Slackのメッセージにカーソルを合わせてリアクションを追加するか、+:emoji:を送って直前のメッセージにリアクションします。測った上限(1人1メッセージ23種類)と、Slack自身のリアクションの意味もまとめました。

Slackにはネタバレを隠す書式がありません。2026年9月29日にDiscordの||text||、Redditの>!text!<、//text//を送ると、3つとも丸見えでした。答えを隠せる回避策はスレッドの返信です。

Slackの不在は🌴 :palm_tree:、移動中は✈️ :airplane:、予定した休みは🗓️で表します。Slackには:ooo:の絵文字がないので、実際のステータスで試したOOO、PTO、BACK MONの絵文字6つを無料で配布します。

Slack has no urgent or priority flag on messages. On October 27, 2026 we checked every menu in the Free plan's message box and message menu and found none. What works instead: a DM, @here or @channel, a reminder on the message, and the reader's VIP and keyword settings.

Slack has no delete-thread button. Deleting the first message leaves 'This message was deleted.' with the replies still attached; the thread only disappears once every reply is deleted too. We tested both in the app and through the API on October 27, 2026.

Delete a Slack file from Files or from the file's own menu with Delete file. In our October 27, 2026 test, Delete message on a file post removed the post but left the file on Slack's servers. We also deleted files in bulk with a short script.

Files you share in Slack are stored on Slack's servers under files.slack.com, not on your computer. Inside Slack you find them in Files and in each channel's Files tab, and downloads go wherever your app or browser saves them. We tested where each one shows up.

A channel canvas shows up as a tab at the top of the channel, in Files > Canvases, and in search under the Canvases filter. We made one on the Free plan on October 27, 2026 and timed how long search took to find a word from its body.

Change Slack's display language in Preferences > Language & region > Language. We switched our test account to Spanish and back on October 27, 2026 and recorded what changed: menus, the clock format, and not your messages.

Change your Slack email under Account > Settings > Email Address: enter your current password and the new address, then confirm it from the new inbox. Admins can change a member's email only on Pro and Business+.

Slack's built-in Translate message is a Slack AI feature on Business+ and Enterprise+. On our Free workspace the message menu had no Translate item, but Slackbot translated a Spanish and a Japanese message when asked.

Current Slack has no way to hide the channel sidebar: no shortcut, no menu item. You can drag it down to 180 pixels and switch the left tab rail to icons only. We checked the web app and the desktop menus.

Slack's Copy message puts four versions of a message on the clipboard: plain text, HTML, markdown and Slack's own HTML. Which one you get depends on where you paste. We read all four.

Cmd+Z or Ctrl+Z undoes typing in the message box and, right after you send, can unsend the message. Deletes, removed reactions and channel leaves have no undo. We tested 8 actions.

Slack search usually fails for one of a few reasons: the message is too new, a date filter excludes it, an operator has a typo, or Free hides older history. We timed the search index and tested each cause.

わかります。参加者の一覧に表示され、サイドバーにも誰が入っているかが出ます。マイクをミュートにし、カメラをオフにして参加することはできますが、見えないように参加する方法はありません。

環境設定のアクセシビリティでAllow animationsを確認します。1回だけ再生されるGIF、アニメーションをオフにしたときの表示、標準でオフになっているワークスペースのGIFピッカーを、実際に試しました。

Slackに貼り付けた標準のマークダウンは、今は表も含めて貼り付けた時点で書式になります。入力したチルダ2つの取り消し線とリンクの記法はならず、マークアップモードはアスタリスクを残し、ボットにはmrkdwnが必要です。10月27日のテスト結果です。

A Slack export is a ZIP of JSON files. We exported our Free workspace, looked inside the ZIP, and opened it with slack-export-viewer and slackdump view to compare how each shows threads, reactions and apps.

On a Free workspace, Admin > Analytics shows one overview page and an Export button with daily message counts. Channel, file and member analytics need a paid plan. We opened every tab and read the CSV.