Quick Answer
Slack messages allow up to 40,000 characters. Channel names are limited to 80 characters. Status text allows 100 characters.
Check Your Character Count
Draft long Slack messages in our free word counter tool to check character count and reading time before sending.
Frequently Asked Questions
What is the Slack message character limit?
Slack messages can be up to 40,000 characters long. This applies to both channel messages and direct messages.
What is the Slack channel name character limit?
Slack channel names are limited to 80 characters. They can only contain lowercase letters, numbers, hyphens, and underscores.
What is the Slack status character limit?
Slack custom status text is limited to 100 characters, plus one optional emoji.
Is there a limit on Slack Canvas?
Slack Canvas documents have no character limit. They are designed for longer-form content and documentation.
Where this data comes from
The sources and check dates in this table come from one versioned data file — the place we record every check we make. The rest of this page, and the limits built into our tools, are still separate copies, so when we correct a figure we correct it in each place. This table is how we keep ourselves honest while we do.
We've checked some of these figures, not all of them yet
Some figures on this page have been checked against the platform's own documentation — those show a source and the date we checked. The rest came across from our older pages and haven't been checked yet, so they say so. We'd rather show you which is which than print a date we haven't earned.
Still to be checked against: Slack Help Centre (slack.com/help) and the Slack API documentation
| Field |
Limit |
Notes |
Source |
Last checked |
| Message |
40,000 |
Extremely generous — one of the highest limits. VERIFIED 2026-09-19. Note: api.slack.com now redirects to docs.slack.dev (a documentation domain migration). |
https://docs.slack.dev/changelog/2018-truncating-really-long-messages/ |
2026-09-19 |
| Channel Name |
80 |
Lowercase letters, numbers, hyphens, underscores |
No source recorded |
Not yet verified against the platform’s own documentation |
| Channel Topic |
250 |
Short description shown at the top of a channel |
No source recorded |
Not yet verified against the platform’s own documentation |
| Channel Purpose |
250 |
Longer description in channel details |
No source recorded |
Not yet verified against the platform’s own documentation |
| Display Name |
80 |
Your visible name in the workspace |
No source recorded |
Not yet verified against the platform’s own documentation |
| Status Text |
100 |
Your custom status message |
No source recorded |
Not yet verified against the platform’s own documentation |
| Status Emoji |
1 |
Single emoji alongside your status |
No source recorded |
Not yet verified against the platform’s own documentation |
| Profile Title |
100 |
Job title in your Slack profile |
No source recorded |
Not yet verified against the platform’s own documentation |
| Thread Reply |
40,000 |
Same as standard messages — VERIFIED 2026-09-19, same source and figure as the message field. |
https://docs.slack.dev/changelog/2018-truncating-really-long-messages/ |
2026-09-19 |
| Canvas |
Unlimited |
Slack Canvas documents have no character limit |
No source recorded |
Not yet verified against the platform’s own documentation |
