Compress Video to 25 MB
25 MB holds about 49 seconds of comfortable 1080p, or 88 seconds at 720p. It is Gmail’s documented attachment limit — and a video compressed to exactly 25 MB will bounce.
Free, no watermark, no account needed. The compressor below is preset to 24 MB so the output lands under 25 MB rather than a couple of percent over it.
Drag and drop a video file to start
Max file size: 500 MB free, up to 1.5 GB with a paid plan
Supported: mp4, webm, mov, mkv, avi, wmv and 33 formats in all
No watermark · files are processed in the cloud and auto-deleted
Where 25 MB comes from
Gmail documents a 25 MB attachment limit, which is where this number comes from and why it is the most-searched size of the six. It is also the one number on this site that is misleading as published.
- Email — Gmail25 MB
The documented figure this size is named after, and the one that does not survive contact with base64.
How long a video fits in 25 MB
The longest clip each resolution can carry inside 25 MB. “Comfortable” means the bitrate clears what that frame size wants; “watchable” means it is soft but holds together. Both columns are arithmetic on the size and the duration; the thresholds they are compared against are recommendations, documented under the table below.
| Resolution | Comfortable up to | Watchable up to | Needs |
|---|---|---|---|
| 4K | 10s | 16s | 20,000 kbps |
| 1440p | 22s | 36s | 9,000 kbps |
| 1080p | 49s | 96s | 4,000 kbps |
| 720p | 88s(1 min) | 167s | 2,200 kbps |
| 480p | 182s(3 min) | 327s | 1,000 kbps |
| 360p | 282s(5 min) | 480s | 600 kbps |
Method: 25 MB spread over the duration, minus 128 kbps of audio and 2% container overhead, then compared against H.264 thresholds derived from published bitrate ladders and reduced by about a third for re-encoded source. A minute inside 25 MB leaves 3297 kbps for video, which is exact. Which resolution that is enough for is a recommendation, not a measurement.
What 25 MB buys at each length
The table above reads by resolution; this one reads by duration. Same arithmetic, the other way round — pick your clip length and see what is left to spend.
| Video length | Bitrate left for video | Resolution it carries | Verdict |
|---|---|---|---|
| 30s | 6,723 kbps | 1080p | Looks fine |
| 1 min | 3,297 kbps | 720p | Looks fine |
| 2 min | 1,585 kbps | 480p | Looks fine |
| 5 min | 557 kbps | 480p | Watchable |
| 10 min | 215 kbps | — | Visibly rough |
| 30 min | — | — | Not realistic |
Method: the bitrate column is arithmetic — 25 MB spread across the duration, minus 128 kbps for stereo audio and 2% for container overhead. It is a hard ceiling, not an estimate. The resolution and verdict columns are a recommendation, derived from published H.264 bitrate ladders and pulled down about a third, because re-encoding footage that has already been compressed once survives lower bitrates than encoding a clean master does. Deliberately conservative — we would rather under-promise than tell you a video will look fine when it will not.
25 MB across lengths and resolutions
The left column is what you have to spend at each length; the cells are what each resolution needs. Green means you clear it comfortably, amber means it is watchable but soft, grey means pick a smaller frame. Reading down a column tells you how long a clip can get before that resolution stops being worth it on a 25 MB limit.
Source: Computed, not measured — no encoder was run to produce this figure · Method: 25 MB spread over the duration, minus 128 kbps audio and 2% container overhead. Thresholds from published H.264 bitrate ladders, reduced by about a third for re-encoded source.
What goes wrong at 25 MB
Email cannot carry binary, so attachments are base64-encoded into text on the way out — which inflates them by about 37%. Providers enforce the limit on the encoded message, not on your file. A 25 MB video becomes a roughly 34 MB message and is refused. The real ceiling for a raw file is about 18 MB. So: compress to 25 MB when a form or an upload dialog asks for 25 MB, and do not compress to 25 MB for email. Almost every guide on the internet repeats Gmail’s figure without this correction, which is why the failure is so common and so confusing — the file matches the stated limit and still bounces.
How to compress a video to 25 MB
Drop the video in
The compressor above is already set to 24 MB — just under 25 MB, so the result lands inside the limit rather than a percent over it.
Trim first if it is long
At 25 MB, length costs more than any quality setting. Cutting a clip in half doubles the bitrate available to every frame that is left.
Download and check the hard frames
Look at motion, faces and gradients rather than the average. Those are where compression fails first, and where a preview at full size tells you something a thumbnail cannot.
25 MB questions
Why did my 25 MB video bounce when Gmail says 25 MB?
Because Gmail measures the encoded message, not your file. Attachments are base64-encoded in transit, which adds about 37%, so a 25 MB video arrives as roughly 34 MB and is refused. The largest raw file that reliably fits a 25 MB limit is about 18 MB.
What size should I actually target for email?
About 18 MB for a Gmail recipient. Less if you do not know what they are on: Outlook.com documents 20 MB and a default Exchange mailbox is 10 MB, and the same base64 inflation applies to both.
So when is 25 MB the right target?
Whenever the limit is measured on the file itself rather than on an email message — web forms, upload dialogs, content management systems, ticketing tools. In those cases 25 MB means 25 MB, and this page’s arithmetic applies directly.
Does zipping the video help?
No. Video is already compressed, so a zip archive of an MP4 is within a percent or two of the original size — and it still gets base64-encoded, so the 37% inflation applies to the archive as well. Compressing the video itself is the only thing that moves the number.
How long a video fits in 25 MB?
About 49 seconds at 1080p, 88 seconds at 720p, and three minutes at 480p. The table above shows the lengths in between and what each one leaves you to spend.
The reasoning behind these numbers
- Gmail says 25 MB. It means about 18.The full arithmetic behind the one number on this site that is misleading as published.
- Base64 encoding, and the 37% it addsWhy the limit is enforced on the message rather than on your file.
- Compress for email insteadPreset to 18 MB, which is the figure that actually sends.
Other target sizes
Not one of these? Work out any size and length in the calculator — same arithmetic, plus what we measured at the bitrate it gives you.