Compress Video for Slack
Slack caps a single file at 1GB. Large videos still upload slowly and are cumbersome for teammates to download, so compressing first can make sharing faster — and the source file never leaves your device during processing.
Slack upload limits
Slack's documented per-file limit is 1GB. On the free plan, access is governed by message and file history retention rather than the old 5GB workspace storage rule, so the main reason to compress is faster transfer and easier playback.
Sources: Slack file upload limits · Slack free plan limitations · Reviewed 2026-06-13
Frequently asked questions
- What is Slack's file upload limit?
- Slack documents a 1GB maximum per file. Free-plan file availability is affected by Slack's retention policy, not the former 5GB shared-storage rule.
- Why are my Slack uploads slow?
- Upload time is bound by file size and your connection's upload speed (usually far slower than download). A 300MB clip compressed to 40MB uploads roughly 7× faster.