Compress Video for Gmail (25 MB Limit)

Gmail caps uploads at Message total 25 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. Cloud encoding keeps running if the tab closes. The no-account trial accepts videos up to 3 minutes and 200 MB; paid plans accept files up to 1.5 GB.

Gmail’s 25 MB number applies to the complete encoded message, not the video on your disk. The 18 MB preset leaves room for base64 and MIME overhead instead of producing a file Gmail immediately turns into a Drive link.

Drag and drop a video file to startTap to choose a video

Checking your file limits…

Supported: mp4, webm, mov, mkv, avi, wmv and 33 formats in all

Output file size:

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Gmail file size limits, and what they really mean

A raw attachment grows by roughly 37% in transit. Aim for 18 MB when you need a real attachment; larger files sent through Gmail on the web are normally replaced with a Google Drive link.

Plan / upload method	Maximum file size
Message total	25 MB Gmail measures the whole encoded message, not the raw video. Base64 and MIME overhead add about 37%, so a 25 MB file does not fit inside a 25 MB message. Gmail on the web replaces oversized attachments with a Drive link.

Limits verified 2026-10-30. Sources: Google — Send attachments with your Gmail message

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

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, and grey means pick a smaller frame. Reading down a column shows how long a clip can get before that resolution stops being worthwhile on Gmail.

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 come from published H.264 bitrate ladders, reduced by about a third for re-encoded source.

How to compress a video for Gmail

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 target-size encode usually lands within a couple of percent of the number you gave it, but we have measured footage that overshoots by up to a tenth — and landing 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 Gmail will accept.

Gmail compression FAQs

Why does a 25 MB video not fit in Gmail’s 25 MB limit?

Gmail measures the whole encoded message. Base64 and MIME formatting make the transmitted attachment larger than the file on disk, so a raw 25 MB video crosses the message ceiling.

What video size should I target for a Gmail attachment?

Use about 18 MB. After encoding overhead, that lands close to 25 MB while keeping safety margin for the message body and headers.

What happens when a Gmail attachment is too large?

Gmail on the web uploads the file to Google Drive and inserts a link instead of attaching the video directly.