Check which Slack editor is active
Slack has a normal visual composer with a formatting toolbar and an optional preference called Format messages with markup. They do not treat pasted content the same way. Slack says that when markup mode is enabled, pasted messages appear as plain text and automatic formatting for bulleted, numbered and indented lists is disabled.
That distinction explains many inconsistent results. A paste that becomes a formatted list in one workspace can remain literal text in another because the editor preference, desktop client or clipboard payload is different.
Slack: visual message formatting · Slack: markup preference and paste behaviour
Standard Markdown, Slack markup and the API are different outputs
Standard Markdown commonly uses two asterisks for bold. Slack markup uses one. Slack's API-oriented mrkdwn has additional rules for links and escaping, while the normal composer can receive rich clipboard content. A string prepared for a webhook is therefore not automatically the best string to paste into the visual editor.
- Visual composer: prefer formatted clipboard content with a readable plain-text fallback
- Markup preference: use Slack's documented markers and visible list characters
- Slack API or workflow: use an API-specific mrkdwn or rich_text renderer, not a composer paste
Nested lists are a recurring, client-sensitive failure
Users have reported nested bullets collapsing to one level, including a cluster of reports after a Slack editor change in early 2026. An older, highly discussed thread also documents people routing text through Slack Canvas, Word or Notes to keep bullets. These reports are anecdotal, but the same loss pattern appears across different years and workarounds, so nested-list fidelity deserves explicit testing.
For an important message, paste a two-level sample before sending the full note. If the hierarchy flattens, use short section headings plus one list level, or keep literal indentation in a code block when exact spacing matters more than rich formatting.
January 2026 Slack nested-list reports · Long-running Slack copy and paste thread
A reliable Slack paste workflow
Paste the source into Pasteful, choose Slack and use the formatted-copy action for the normal visual composer. In Slack, check one heading, one link and the deepest list before sending. If Slack shows literal Markdown, make sure you did not choose raw mrkdwn by mistake and check whether markup mode is enabled.
Slack also documents an Apply markdown formatting shortcut: Command-Shift-F on macOS or Control-Shift-F on Windows and Linux. It can be useful for a pasted draft, but it does not turn unsupported structures such as tables into native Slack features.
What Slack cannot preserve
Slack's documented composer tools do not include tables. Convert a small table to labelled rows; use a code block only when fixed-width alignment remains readable. A pasted @name is also not a guaranteed notification because real mentions depend on workspace identity data.
Keep the meaning and make any loss of formatting clear. Trying to imitate every source feature usually leaves literal syntax in the message.
Paste it into Pasteful. It stays in this tab.