Compress AVIF Images for Slack
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. Next-generation image format based on the AV1 video codec. Offers superior compression to both WebP and JPEG. Use ImageSmith to compress your AVIF images to the ideal file size for Slack — target under 1,000,000KB for optimal performance. Processing is fully browser-based — no server uploads.
Recommended format
JPEG
Max file size
1,000,000KB
Dimensions
800×600 or smaller for inline chat images
✓Slack generates automatic thumbnails — keep shared images under 1MB
✓PNG for screenshots and diagrams, JPEG for photographs
✓GIFs animate automatically in Slack — keep under 10MB for smooth playback
✓Avoid oversized images in channel history — they slow channel loading
Compress AVIF for Other Platforms
Compress AVIF for Slack — FAQ
Slack works best with images under 1,000,000KB. Recommended dimensions: 800×600 or smaller for inline chat images. ImageSmith can compress AVIF images to any target size in seconds.
Slack primarily supports JPEG, PNG, GIF, WEBP. Converting to JPEG is recommended for best compatibility.
Upload your AVIF image to ImageSmith, set a target size under 1,000,000KB, and compress. Slack generates automatic thumbnails — keep shared images under 1MB
Slack supports files up to 1GB on paid plans. However, for smooth inline image loading in channels, keep images under 1MB. Very large images require a click to preview.