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Signal says the attachment is too large? Get a video under 100 MB

Signal does not publish its attachment limit on its support site. About 100 MB is the long-standing figure, and one recent report says it was raised to 200 MB, which we could not confirm. Staying under 100 MB is safe either way.

  • Nothing is uploaded. Your browser does the compression, so the file stays on your device.
  • Lands under the real limit. We aim a little below it, so the upload goes through first time.
  • Fast. A 30 second 1080p clip fits into 10 MB in about two seconds on a desktop.
Where are you sending it?

Custom size 100 MB. We aim for 97.00 MB, a small safety margin so the file never lands just over.

Sent to our servers: 0 bytes. It all happens in this tab.

When you need 100 MB

A private messenger deserves a private compressor: this one runs inside your browser, so the clip is never sent to us or anyone else before you send it on Signal.

What to expect

Several minutes of 720p or a couple of minutes of 1080p, depending on motion.

How much video fits in 100 MB

Worked out with the same maths the compressor uses, for a typical 1080p phone or screen clip with sound. Fast motion needs more room, still scenes and screen recordings need less.

Clip lengthResolution we pickHow it looks
10 seconds1080pSharp
30 seconds1080pSharp
1 minute1080pSharp
2 minutes1080pSharp
5 minutes720pSharp
10 minutes540pGood on a phone

How we hit the number

We work out how many bits each second of video can use: the target size, minus a safety margin, divided by the length, minus the audio. Then we pick the largest resolution that still looks clean at that rate and encode with your browser's built-in video encoder. If the result is still over, we automatically try once more at a lower rate.

The target we aim for is 97.00 MB, which is 3.00 MB under 100 MB, so the file is not turned away over a few bytes.

Questions people ask

Why does a smaller file also help on Signal?

Encrypted files upload and download as one piece, so a smaller file means less waiting and less mobile data for the person receiving it.

Is this size official?

No, it is a typical figure. Signal does not state it on its help pages.

Related

Limits change. We link the official page wherever there is one, and the safety margin means a small change is unlikely to matter. Last updated 2026-11-09.