Compress Images for Slack — Free & Instant
Slack displays images inline in messages and generates previews for shared links. Smaller images load faster in busy channels and improve performance for remote teams. Use ImageSmith's free image optimizer to compress your Slack images directly in your browser — no account needed, no watermarks, and no ads. Target under 1,000,000KB per image for best results on Slack.
Max File Size
1,000,000 KB
Recommended Format
JPEG
Dimensions
800×600 or smaller for inline chat images
Slack Compression Tips
- 1.Slack generates automatic thumbnails — keep shared images under 1MB
- 2.PNG for screenshots and diagrams, JPEG for photographs
- 3.GIFs animate automatically in Slack — keep under 10MB for smooth playback
- 4.Avoid oversized images in channel history — they slow channel loading