No upload · No size limit · No watermark · No signup
Compress video for email — fit the attachment limit, free
Email providers like Gmail and Outlook cap attachments around 25 MB total, and email actually encodes attachments in Base64, which adds roughly a third to their size — so a file that looks fine on disk can still get rejected once it's in a message. This tool compresses your clip locally in your browser — nothing is uploaded — and defaults to a 20 MB target with room to adjust if your provider is stricter.
How it works
- Drop a video file. It stays on your device the whole time.
- Adjust the target size if you need to — it starts at 20 MB, with headroom under the usual 25 MB attachment ceiling — then press compress.
- Watch the progress bar, check the under-the-limit indicator, then download it and attach it to your email. If it still bounces, lower the target a few MB further to cover Base64 overhead.
Frequently asked questions
Is my video uploaded to a server?
No. Decoding, re-encoding and muxing all happen inside your browser using WebCodecs and mediabunny — the video file never leaves your device, even for huge files, because it's read and written in small chunks instead of all at once.
Why 20 MB when Gmail and Outlook allow up to 25 MB?
25 MB is the ceiling most providers quote, but it isn't all headroom for your file: email attachments are Base64-encoded in transit, which inflates their size by roughly a third, and some providers count that inflated size against the limit rather than your raw file size. Targeting 20 MB keeps the encoded attachment comfortably under 25 MB instead of running right up against it.
My email still bounced back as too large — what now?
Some workplace mail servers set a stricter limit than 25 MB, or route through a gateway that adds its own overhead on top of Base64 encoding. Lower the target size field to 15 MB or even 10 MB and compress again — or switch to sharing a link from cloud storage instead of attaching the file directly, which sidesteps size limits entirely.
What if my video won't fit under the target even at the lowest quality?
Very long clips need a very low bitrate to fit a small target, and the tool refuses to go below a quality floor that would make the video unwatchable. If the result still comes back over your target, trim the clip shorter or lower the resolution by re-exporting a smaller version first.
Why does my browser say it isn't supported?
This tool needs WebCodecs, specifically a working H.264 video encoder, which current Chrome, Edge and Firefox on desktop or Android provide. Every browser on iPhone and iPad shares Apple's WebKit engine, which doesn't expose one yet, so the compressor is unavailable there.