Compress Video for Slack
Slack caps uploads at Every plan 1 GB, Recorded clips 1 GB. VidSmaller compresses any video down to 200 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.
Slack’s file size cap is unusual: it does not change with your plan. Free, Pro, Business+ and Enterprise Grid all get 1 GB per file. What changes is how long the file stays visible, and that is the constraint most teams actually run into.
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
Slack file size limits, and what they really mean
The 1 GB per-file ceiling is generous enough that most screen recordings clear it without help. The reason to compress for Slack is different: a 900 MB demo video makes the channel slow to load, eats the workspace storage quota that is shared across everyone, and takes a colleague on hotel wifi four minutes to open.
| Plan / upload method | Maximum file size |
|---|---|
| Every plan | 1 GB Unusually, the per-file cap does not change with your plan. What changes is retention: on the Free plan you lose visibility of files older than 90 days. |
| Recorded clips | 1 GB Slack’s built-in audio and video clips are capped at 5 minutes regardless of file size. |
Limits verified 2026-09-06. Sources: Slack — Add files to Slack · Slack — Usage limits for free workspaces
What 200 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 200 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 |
|---|---|---|---|
| 1 min | 27,275 kbps | 4K | Looks fine |
| 5 min | 5,353 kbps | 1080p | Looks fine |
| 10 min | 2,612 kbps | 720p | Looks fine |
| 30 min | 785 kbps | 360p | Looks fine |
| 1 h | 329 kbps | 360p | Visibly rough |
Method: the bitrate column is arithmetic — 200 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.
200 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 Slack.
Source: Computed, not measured — no encoder was run to produce this figure · Method: 200 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 Slack
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 200 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 Slack will accept.
Slack compression FAQs
What is the Slack file upload limit?
1 GB per file, on every plan including Free — Slack is unusual in not gating file size behind a subscription. Slack’s own recorded clips are separately capped at 5 minutes of runtime regardless of size.
Why compress a video if Slack allows 1 GB?
Because the per-file cap is not the constraint that hurts. Workspace storage is pooled across your whole team, so one person posting 900 MB demos weekly burns through it for everybody. And a large file in a busy channel is a genuinely bad experience for anyone on a slow connection — Slack does not stream video, it downloads it.
What happens to my Slack files after 90 days on the free plan?
They stop being visible or searchable. The data is not deleted — upgrading restores access — but for practical purposes a file older than 90 days does not exist on a free workspace. If a recording matters, do not let Slack be the only copy of it.
What size should a screen recording be for Slack?
Around 100 to 200 MB is a good target for a ten-minute walkthrough. Screen content compresses extremely well because most of the frame does not change between frames, so you can be much more aggressive than you would be with camera footage and still keep text sharp. Keep the resolution at 1080p so code and UI stay readable — that matters far more here than bitrate does.