The limits
The 25 MB ceiling counts the encoded size of the attachment, which is roughly a third larger than the file on disk — mail attachments are Base64-encoded in transit. A 24 MB file can therefore still be refused. Checked 19 September 2026.
- Sending — 25 MB total per message, attachments and message combined.
- Receiving — 50 MB total, so someone can send you more than you can send them.
- Over 25 MB — Gmail does not refuse it. It uploads the file to Google Drive and sends a link instead.
- Other providers differ: Outlook caps at 20 MB for many accounts, and some corporate mail servers are stricter still.
Why the Drive fallback is often not what you want
When Gmail converts an oversized attachment into a Drive link, the file lands in your Drive and counts against your storage. The recipient needs permission to open it, which is a common failure when they are outside your organisation or not signed in to a Google account at all. And the link can stop working later if you move or delete the file.
A 20 MB attachment arrives in the message, opens on any mail client, and keeps working forever. For anything you actually want the recipient to just watch, fitting under the limit is worth the minute it takes.
Why your video is over 25 MB
Because modern phones record at very high bitrates. A minute of 4K from a recent handset is commonly 300–500 MB, so even ten seconds can exceed the cap. Screen recordings are large too, though they compress far better than camera footage because most of the frame never changes.
Dropping the resolution does most of the work. Going from 4K to 1080p removes about three quarters of the pixels before any quality setting is touched, which shrinks the file far more than turning the quality down ever will.
Getting under the limit
The email preset targets roughly 20–25 MB: H.264 in an MP4 container at a bitrate and resolution chosen to land under the cap with headroom for the Base64 overhead. MP4/H.264 also matters for the recipient — it is the combination that plays inline in essentially every mail client and on every phone.
If the clip is long enough that 25 MB means visible mush, trim it first. Thirty watchable seconds beat three minutes of smeared blocks.
Nothing is uploaded to compress it
The compression happens inside your browser using ffmpeg compiled to WebAssembly. We serve the code; your machine does the work. There is no upload step, so there is no cap on the size of the video you start with, and the footage never reaches anyone else's server on its way to your recipient.