Compress Video for Outlook (20 MB Limit)

Outlook caps uploads at Outlook.com / internet email account 20 MB, Exchange account default 10 MB. VidSmaller compresses any video down to 14 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.

Outlook limits depend on the account behind the app. Outlook.com commonly uses a 20 MB total-message ceiling, while an Exchange administrator can keep the lower 10 MB default or set a different policy.

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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Outlook file size limits, and what they really mean

The limit covers the encoded message, so the raw video must be smaller. The 14 MB preset is a practical Outlook.com target; for a work Exchange account, confirm the organization’s policy.

Plan / upload method	Maximum file size
Outlook.com / internet email account	20 MB Microsoft documents 20 MB as the default total message size for internet email accounts in Outlook. Encoding overhead means the raw attachment must be smaller.
Exchange account default	10 MB Microsoft documents a 10 MB default for Exchange accounts. An administrator can raise it, but senders cannot assume they did.

Limits verified 2026-10-30. Sources: Microsoft — Reduce attachment size to send large files with Outlook

What 14 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 14 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	3,708 kbps	720p	Looks fine
1 min	1,790 kbps	480p	Looks fine
2 min	831 kbps	360p	Looks fine
5 min	256 kbps	—	Visibly rough
10 min	64 kbps	—	Visibly rough

Method: the bitrate column is arithmetic — 14 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.

14 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 Outlook.

Source: Computed, not measured — no encoder was run to produce this figure · Method: 14 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 Outlook

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 14 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 Outlook will accept.

Outlook compression FAQs

Is the Outlook attachment limit 20 MB or 10 MB?

Both numbers can be correct. Microsoft documents 20 MB for internet email accounts in Outlook, while Exchange accounts commonly start with a 10 MB default that administrators can change.

Why is the preset 14 MB instead of 20 MB?

Attachments expand when email encodes them. A 14 MB raw video leaves room for that overhead and the rest of the message.

Will compressing guarantee delivery to a work Outlook inbox?

No tool can see the recipient organization’s Exchange policy. A company can enforce a smaller custom limit or block video attachments.