Compress video to 20 MB
The attachment ceiling of classic Outlook and plenty of company portals — compressed on your own device, guaranteed to land under 20 MB.
Drop your video here
or
MP4, MOV, WebM, MKV, AVI and more — any size, no upload
🔒 Files never leave your device — everything runs in your browser.
20 MB is the corporate upload wall: it is the long-standing default attachment cap in Outlook, and the same number shows up across intranet portals, applicant-tracking systems and older document-management tools. Mail servers make it stricter still — attachments are re-encoded for transport and can grow by a third, so a 19.9 MB file may bounce even where 20 MB is the official cap.
That transport overhead is why this page's preset does not aim "just under 20" — the compressor targets the byte count with margin, so what you attach is what arrives. Twenty megabytes is a comfortable budget for a few minutes of screen recording or a meeting excerpt; for longer recordings the tool steps resolution down before it ever lets the picture smear.
How it works
- Drop your file
Any common format, any size. Nothing is uploaded — the tool runs in your browser.
- Pick your target
Use the presets above — this page's defaults are tuned for compress video to 20mb — or type any size.
- Download
Your converted file is ready on your device — nothing to wait for, nothing to delete from a server.
Frequently asked questions
Why did my 19 MB attachment still bounce?
Email transport encodes attachments in a format that inflates them by roughly a third, and many servers check the inflated size. If a recipient's server enforces 20 MB strictly, aim for the 16 MB preset — the compressed result survives the inflation with room to spare.
What fits comfortably in 20 MB?
Several minutes of screen recording or a couple of minutes of camera footage at readable quality. The compressor always picks the highest resolution the bitrate can sustain — text in screen recordings stays legible longer than you might expect.
Is there a better way than email for bigger videos?
Above the attachment caps, a link beats an attachment: compress to a manageable size here, then share via your drive of choice. The compression still pays off — uploads finish sooner and previews load instead of buffering.
Is my file uploaded to a server?
No. ConvertUno runs entirely in your browser on your own device. Your file never leaves your computer or phone — there is no upload at all.
Is it really free, with no watermark?
Yes. Processing happens on your device, so serving you costs us almost nothing — no watermark, no account, no file-size limit, no daily quota.