Compress a video for Slack
Slack accepts large uploads (up to 1 GB per file at the time of writing), but workspaces on the free plan have limited visible history, and big videos are slow for teammates on VPNs or mobile. A demo or bug recording compressed to 25 MB previews inline in Slack and downloads in seconds — and since the file never leaves your browser during compression, internal footage stays internal.
Last updated September 2026
Compress for Slack (25 MB) →How to do it
- Open the compressor with a 25 MB target.
- Load your screen recording or clip (MOV from macOS, MP4 or MKV from OBS all work).
- Trim to the relevant part — the bug repro or the feature being demoed.
- Choose 1080p for screen recordings so text stays readable; 720p for camera footage.
- Compress, download and drop the MP4 into the Slack message box.
Tips
- Screen recordings compress very well because most of the screen doesn't change between frames.
- Text readability depends on resolution more than bitrate — avoid 480p for UI recordings.
- Useful for confidential material: compression happens locally, with no third-party upload site involved.
FAQ
What's Slack's file upload limit?
At the time of writing, Slack allows files up to 1 GB. Smaller files still load and preview much faster for everyone.
Will it play inline in Slack?
Slack previews common MP4 (H.264/AAC) files inline, which is the format this tool outputs.
Is my recording uploaded when compressing?
No. It's processed on your device; it only goes to Slack when you post it.