Specs and limits

Mastodon specs and limits

Mastodon text is limited to 500 characters, counted by code points. This page lists every text, media and posting rule 1Post checks for Mastodon: counts, sizes, lengths, threads and the daily cap. Where Mastodon publishes a figure on its own page we cite it with the date we read it.

Also:Schedule Mastodon posts Social media posting limits by network Social media posting limits table

Updated 2026-10-23

What 1Post checks for Mastodon

Rule	What 1Post checks
Text limit	500 characters, counted by code points
Media accepted	Images, GIFs, Video
Images per post	4
Videos per post	1
Images and video together	Not in one post
Threads	Yes, as a chain of replies
First comment	Yes
Polls	2 to 4 options; not together with media
Posts per day, per connected account (1Post)	100

These are the limits 1Post applies in the composer, so a post that passes is not refused for them when it is sent. A network can still refuse a post for reasons outside these rules, such as its content policies.

What Mastodon publishes

Fact	Source
On the instance read, a post holds 500 characters and up to 4 attachments, each URL counts 23 characters, and a poll has up to 4 options of 50 characters. Every instance sets its own values.	Mastodon documentation: Instance entity, read 2026-10-22

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Questions

How is Mastodon text counted?

Mastodon text is counted by code points. The character counter applies the same rule.

Where do these Mastodon limits come from?

They are the limits 1Post checks before a post is sent. Figures the network publishes on its own page are cited above with the date read; the rest are checks 1Post sets.

How often is this page updated?

When a network changes a rule or we read a newer figure, the page changes with it. The date at the top shows the last change.