What are your Mastodon server's real limits?
Mastodon's default post limit is 500 characters, but every server sets its own and many raise it: hachyderm.io allows 2,263 and infosec.exchange allows 11,000. Servers also decide how much a link costs (usually 23 characters however long the URL is, though GoToSocial charges 25), how many images a post can carry, and how long alt text can be. This page reads those numbers from your own server's public API and counts your draft against them.
Public data only. No login, no token and never an app password — your browser asks your server directly and nothing is stored.
Three real servers, three different answers
| Server | Characters | Versus the default |
|---|---|---|
| mastodon.social | 500 | the default |
| hachyderm.io | 2,263 | 4.5× the default |
| infosec.exchange | 11,000 | 22× the default |
Checked 8 September 2026. Enter your own server above to read its current figures straight from its API.
Why the answer isn't 500
Mastodon ships with a 500-character default, and almost every guide repeats it as if it were a property of the network. It is not — it is a setting in a configuration file, and the person running your server can change it. Many have.
The same is true of the rest: how many images a post can carry, how long an image description can be, how large a video may be, and how much a link costs. That last one is the detail people miss most often. A link is charged a fixed number of characters however long the URL actually is, so a 200-character tracking link costs the same as a short one. On Mastodon that figure is 23. Servers running GoToSocial charge 25, which is why this page reads the number from your server rather than assuming it.
Every figure here comes from your server's own public API in your browser — the same endpoint any Mastodon client reads when it connects. Nothing is sent to us, and the count is deliberately a little conservative: it counts what remains after the link and mention discounts as code points, which is an upper bound on how your server counts. If this page says your draft fits, it fits.
Posting to more than one network? The limits differ everywhere — see the limit for each one.
Common questions
- What is the Mastodon character limit?
- It depends on the server you post from. Mastodon ships with a 500-character default, but each server can raise it and many do — hachyderm.io allows 2,263 characters and infosec.exchange allows 11,000. Enter your server above to see its real limit.
- Why does my server allow more than 500 characters?
- The limit is a server setting, not a property of Mastodon itself. Anyone running a server can raise it, and administrators often do to suit the community they host. Servers running other fediverse software, such as GoToSocial, ship with different defaults again.
- Do links count against the Mastodon character limit?
- A link costs a fixed number of characters however long the URL is — 23 on Mastodon, and 25 on GoToSocial. Servers publish this figure themselves, so this page reads it from yours rather than assuming. The server part of a remote mention like @you@example.social is free; only @you is counted.
- How long can Mastodon alt text be?
- Mastodon's default is 10,000 characters per image description, but like the post limit it is a per-server setting — GoToSocial defaults to 5,000. Your server's real figure appears above once you check it.
- How many images can one Mastodon post have?
- Four on a default Mastodon server. Other fediverse software differs — GoToSocial allows six. The number your server reports is shown above.
Post to Mastodon on a schedule
PostDaily publishes to Mastodon on a schedule you set once — threads, images and alt text included, with the same limits checked before anything goes out. Free plan, no credit card.
More free tools: Bluesky best time to post