What limits apply to the Matrix service?

Note: This article discusses technical limits, like file size limits, data retention periods, and rate limits. If you're looking for information about what is and isn't allowed on our Matrix server, please take a look at our getting started guide for Matrix and our Terms of Service and Code of Conduct.

Rate Limits

There is no overall limit on how frequently you can send messages, or how many messages you can send. If you send a very large number of messages or events in one of our public rooms in a very short period of time, our Abuse Management Bot (Draupnir) may detect this as spam and ban you from our public rooms. If this happens in error, send us a ticket to have the ban reversed.

It's good to keep in mind that sending a flood of messages in a row without waiting for a response may annoy admins or mods in other Matrix rooms, and possibly result in you being kicked or banned from those rooms.

File Size and Type Limits

You can post images, videos, and files of most other types in Matrix rooms. The maximum file upload size on our server is 150MiB. When posting media, be mindful of whether the room you're posting is encrypted. If it's not, media that you post will be visible to the admins of any Matrix server joined to the room, in addition to the users in the room. These admins may have varying privacy policies, or no privacy policy at all.

You shouldn't assume it's safe to post anyone's personal information, photos or videos, including your own. Posting others' personal information without their consent also violates our Terms of Service.

Overall Storage Limits

In order to perform well, Matrix media requires very fast local storage that's more expensive than typical "cloud storage". We don't currently place storage limits on individual Matrix users, but we expect that you'll be mindful of other users and make fair use of media uploads. In other words: it's absolutely fine every now and then to post a file to a "Notes to Self" room with only you in it. It's not OK to use Matrix as your personal cloud storage.

If we find that you're uploading many times more data than an average user, we'll reach out to you to discuss the situation and come up with a solution. For example, if you're exchanging gigabytes of videos every day in a room with a few of your friends, we might agree to set a shorter retention period on that specific room to keep resources available for others.

You won't be banned for being a high-volume uploader, except in cases of very obvious abuse.

Data Retention

Our current data retention periods for Matrix are as follows:

• Events, like joining and leaving a room, changing your display name, or posting a message, are retained indefinitely if created by 4d2.org users. For events from users on other servers, the retention period is 720 days. Past this point, whether you can reliably scroll back in the room history will depend on how long other servers are retaining their events, and whether those servers are still online.
• Media files uploaded to our server are retained for 720 days. After this, they are deleted and will no longer be available, unless they were cached by another server with a longer retention period.
• Media files uploaded to other servers are cached locally for 180 days from the last time they were accessed. After this, the files are purged from our cache. If the media is accessed again after this, and it's still available from the server where it was initially uploaded, it will be fetched again and our cache retention period will start over.

We may shorten these retention periods in the future to keep adequate storage available for everyone.