Compress Video for Email
Email caps uploads at Gmail 25 MB, Outlook.com 20 MB, Exchange / work mail 10 MB. VidSmaller compresses any video down to 18 MB so it fits on the first attempt — H.264 MP4 out, no watermark, nothing to install, no account needed to try it. Source files up to 500 MB without an account, 1.5 GB on a paid plan.
Almost every page about emailing a video tells you Gmail’s limit is 25 MB. That is true and it is misleading, and it is why people compress to exactly 25 MB and watch the message bounce anyway.
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
Email file size limits, and what they really mean
Email attachments are base64-encoded in transit, which inflates them by about 37%. Gmail measures the encoded size. So a 25 MB video arrives at Google as roughly 34 MB and is refused. The real ceiling for a raw file is around 18 MB — which is the number we pre-set, and the number nobody else tells you.
| Plan / upload method | Maximum file size |
|---|---|
| Gmail | 25 MB Gmail measures the base64-encoded attachment, which is about 1.37x the raw file. A 25 MB video is roughly 34 MB on the wire and bounces. The real ceiling for a raw file is about 18 MB. |
| Outlook.com | 20 MB |
| Exchange / work mail | 10 MB Microsoft ships a 10 MB default for Exchange accounts. Your administrator may have raised it; you cannot assume they did. |
Limits verified 2026-09-06. Sources: Google — Send attachments with your Gmail message · Microsoft — Reduce attachment size
What 18 MB actually buys you
Every other page tells you the limit and stops there. The limit is the easy half. Here is the half that decides whether your video is watchable: at a 18 MB target, this is exactly how much bitrate is left for each duration, and the largest resolution that bitrate can carry without falling apart.
| Video length | Bitrate left for video | Resolution it carries | Verdict |
|---|---|---|---|
| 30s | 4,805 kbps | 1080p | Looks fine |
| 1 min | 2,338 kbps | 720p | Looks fine |
| 2 min | 1,105 kbps | 480p | Looks fine |
| 5 min | 365 kbps | 360p | Visibly rough |
| 10 min | 119 kbps | — | Visibly rough |
| 30 min | — | — | Not realistic |
Method: the bitrate column is arithmetic — 18 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.
18 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 email.
Source: Computed, not measured — no encoder was run to produce this figure · Method: 18 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.
How to compress a video for email
Drop your video in
MP4, MOV, MKV, AVI, WebM and 33 formats in all. Nothing to install — your browser uploads over a one-time link and the file never touches a third party.
The target is already 18 MB
We pre-set it below the hard ceiling on purpose: a two-pass encode lands within a couple of percent, and landing two percent over a hard limit means the upload fails. Change it if you want a different number.
Download and upload
Encoding runs on our servers, so you can close the tab. The result comes back with no watermark on any plan, in an MP4 that email will accept.
Email compression FAQs
What size video can I attach to an email?
About 18 MB of actual video, if you want it to work everywhere. Gmail’s advertised limit is 25 MB and Outlook.com’s is 20 MB, but both measure the base64-encoded attachment, which is roughly 1.37x the file on your disk. Work email is often worse: Microsoft ships a 10 MB default for Exchange accounts, and plenty of administrators never change it.
Why did my email bounce when the video was under 25 MB?
Base64 encoding. Email cannot carry raw binary, so attachments are re-encoded into text, and that costs about 37% in size. Your 24 MB video is a 33 MB message. Gmail checks the message, not the file. Compress to 18 MB and the encoded message lands around 24.7 MB, just inside.
Should I use a Drive or Dropbox link instead?
For anything long, yes — and Gmail will do it for you automatically above 25 MB. But a link is worse for the recipient in real ways: it needs a second click, it can be blocked by corporate security, it expires, and it leaks who opened it and when. For a clip that genuinely fits in 18 MB, an attachment is the better experience.
How long a video fits in 18 MB?
At 720p, comfortably around two minutes. At 1080p, closer to one. Past about five minutes you are into territory where 480p is the honest answer — see the table above for the exact arithmetic at each length. If the recording is a screen capture rather than camera footage, you will do considerably better than these numbers, because screen content compresses far more efficiently than moving scenery.
The reasoning behind these numbers
- Why 25 MB is the wrong target for emailThe size page for the number Gmail documents, and the 37% that makes it fail.
- Gmail says 25 MB. It means about 18.Attachments are base64-encoded in transit, so the number on the label is not the number you can send.
- Losing 70% of the file and none of the qualityMost phone recordings carry enough slack to fit an inbox without a visible change.