Compress Video for Email
The "25 MB limit" actually fits about 18 MB of video. Aim there.
Runs entirely in your browser. Your videos never leave this device.
Gmail caps attachments at 25 MB and Outlook at 20 MB — but the limit applies to the encoded message, and email encoding inflates attachments by roughly a third. That's why a 24 MB video bounces from Gmail. Compress to about 18 MB for Gmail or 14 MB for Outlook with exact target-size mode, and the file goes through as an ordinary attachment.
Why did my 24 MB video fail to send in Gmail?
Because email encodes attachments in Base64, which inflates them by about a third — your 24 MB video became roughly 32 MB in transit, and Gmail's 25 MB limit applies to that encoded size. Keep the actual file at about 18 MB or less and it fits. Target-size mode here can hit that number exactly.
The facts that matter
| Gmail attachment limit | 25 MB (measured after encoding) |
|---|---|
| Outlook attachment limit | 20 MB |
| Encoding overhead | Base64 adds ~33% to every attachment in transit |
| Real safe size for Gmail | ~18 MB |
| Real safe size for Outlook | ~14 MB |
| If you go over | Gmail swaps the file for a Google Drive link; Outlook suggests OneDrive |
Get a better result
- Rule of thumb: safe attachment size is roughly the stated limit times 0.75 — Gmail's 25 MB means ~18 MB, Outlook's 20 MB means ~14 MB.
- Sending to a work address? Aim for 10 MB — corporate mail servers frequently reject messages the big providers would accept.
- Body text, signatures, and inline images count toward the same message limit, so leave a little headroom below your target.
- Sending several clips? Split them across separate emails so the combined attachments don't blow the per-message cap.
- Use exact target-size mode when you're close to the line; the automatic retry re-encodes if the first pass lands over.
Frequently asked questions
What are the attachment limits for Gmail and Outlook?
25 MB for Gmail and 20 MB for Outlook — but both measure the encoded message, not the raw file. After Base64's ~33% overhead, the practical ceilings are about 18 MB and 14 MB of actual video.
What size should I compress my video to?
18 MB for Gmail, 14 MB for Outlook, or 10 MB if you don't know the recipient's provider — corporate mail servers are often stricter than either. Type the number into target-size mode and the bitrate is computed from your video's length automatically.
Isn't it easier to just send a Drive or OneDrive link?
Sometimes — but links can expire, require sign-ins, or get blocked by corporate filters. A real attachment lands in the inbox and stays there. For a short video, compressing to attachment size is usually less hassle for both of you.
Will the recipient be able to play it?
Yes — output is MP4 with H.264 video and AAC audio, which opens in mail-client previews, on every phone, and in every desktop player. Aspect ratio and frame rate are preserved.
How much quality survives at 18 MB?
It depends entirely on length: 18 MB spread over one minute of video is a healthy bitrate, while 18 MB over twenty minutes is not. For long footage, expect visible softening — or share a link instead and use a quality preset here just to make the download smaller.
Is the video uploaded anywhere to compress it?
No — everything runs locally in your browser via ffmpeg.wasm, so the file never leaves your device. No signup, no watermark, and no limit on how many videos you compress.