Threads and Bluesky Image Guide: Sizes That Do Not Get Cropped

Threads and Bluesky Image Guide: Sizes That Do Not Get Cropped

Threads and Bluesky reward text-first visuals: screenshots, quote cards, charts, and single-idea graphics. Crops hurt these formats more than photos because every lost line changes the meaning. Export the right shape and your posts survive intact.

What Sizes Work on Threads and Bluesky?

Verified 2026 targets:

Square 1080 x 1080 is the safest default when cross-posting. Portrait 1080 x 1350 earns more screen space for single-idea graphics.

Set exact pixels in the image resizer before posting.

Why Crops Happen Here

Both apps display images in constrained feed cards:

• Mixed aspect ratios get center-cropped in previews
• Wide screenshots lose left and right edges on phones
• Long screenshots get truncated with a tap-to-expand step many readers skip
• Text near edges disappears behind rounded corners and tap targets

The fix is composition plus format: safe zones for layout, PNG for text legibility, light compression for clean edges.

This workflow is privacy-focused and secure, with fast processing where no data leaves your device.

How to Export Images That Survive

1. Pick one ratio per idea

One idea, one card, one ratio. Do not pack four screenshots into one landscape collage and hope phones show it all. Split long threads into sequential square or portrait cards.

2. Protect text with PNG

Screenshots, code snippets, charts, and quote cards must stay readable:

• Export text-heavy cards as PNG
• Keep body text large enough to read without tapping
• Use high contrast and generous line spacing

Photos can stay JPG at quality 80-85. Convert web copies with JPG to WebP or PNG to WebP when publishing the same art to a site.

3. Respect safe zones

Keep headlines, faces, and key data at least 80-100 px inside every edge at 1080 px width. Center the punchline so center crops cannot remove it.

4. Compress lightly

Target 200-500 KB for feed cards. Use the image compressor and zoom to 100 percent on text edges before upload.

5. Clean before posting

Screenshots can carry device and location traces from originals. Check with view metadata and strip with the JPG metadata remover. Brand repostable cards with photo watermark or text watermark.

Best Practices

• Design mobile-first: if it only reads well on desktop, redesign it
• Limit cards to one claim plus one visual proof
• Number carousel frames so reposts keep the order clear
• Alt-text every chart with the core takeaway for accessibility
• Archive masters so you can re-export when feed layouts change
• Cross-check sizes in the social image sizes cheat sheet

Platform-Specific Notes

Threads

Portrait cards earn presence but demand discipline: short headlines, large type, minimal fine print. Link previews prefer 1200 x 630 art, so create a dedicated Open Graph crop instead of reusing the feed square.

Bluesky

Image handling is straightforward, but some clients show only a preview until tap. Front-load the message into the visible preview area. Quote-post screenshots perform well when text is large and attribution is visible.

Compare with larger networks: best image formats for Twitter, TikTok image sizes 2026.

Common Mistakes to Avoid

• Posting wide desktop screenshots without a mobile crop
• Saving quote cards as low-quality JPG
• Burying the headline near the edge where previews crop it
• Uploading 4 MB files expecting sharper results than clean 300 KB exports
• Reposting compressed downloads instead of exporting from masters

Conclusion

Threads and Bluesky reward clarity: square or portrait ratios, PNG for text, generous type, center-weighted composition, and light compression. Design for the preview, not the full-size tap.

Prep your next card: resize in the image resizer and finish in the image compressor.

Related Guides

• Social Image Sizes 2026: One Cheat Sheet
• How to Fix Blurry Social Uploads
• Why Are My Images Pixelated?