3:1, such as 1500 × 500 or 3000 × 1000 pixels, as a PNG or JPEG under 1 MB.
Free tool by Mydrop, no signup
Free Bluesky image resizer
A Bluesky banner is 3:1 (1500 × 500 pixels), the avatar is square, and post images take any ratio under 2 MB: resize any photo here.
1Pick the network and size
2Add your photo
3Adjust and download
Post it to Bluesky at the right size
Mydrop shows each image in the real Bluesky preview and publishes on schedule, next to 9 more networks.
Your photo never leaves your device: it is resized in your browser and nothing is uploaded.
How to size images for Bluesky
Any ratio, under 2 MB
Bluesky enforces no ratio for post images. Each image must stay under 2 MB (the limit rose from 1 MB in April 2026), up to 4 per post.
Banner: 3:1, under 1 MB
The profile banner is 3:1, such as 1500 × 500 or 3000 × 1000, and must be a PNG or JPEG under 1 MB.
Avatar: square, under 1 MB
The avatar is shown as a circle. Upload a square of 1000 × 1000 or 400 × 400, under 1 MB.
Example: “A 4,032 × 3,024 photo for a Bluesky banner” = a 4,032 × 1,344 crop, saved at 1,500 × 500
Limits checked on October 10, 2026, against Bluesky's open protocol.
Bluesky size guide
Every Bluesky image size for 2026
Bluesky's limits come from its open protocol. Here is each one for posts and profiles.
| Format | Size (px) | Ratio | Good to know |
|---|---|---|---|
| Post image | 1,600 × 900 | 16:9 | Any ratio works; 16:9 is a safe choice. Up to 4 images, under 2 MB each. |
| Profile banner | 1,500 × 500 | 3:1 | Profile banner, 3:1, PNG or JPEG under 1 MB. |
| Profile picture | 1,000 × 1,000 | 1:1 | Profile picture, square, under 1 MB. |
Bluesky added a gallery post type of up to 10 items to its protocol in June 2026. Until the app shows it everywhere, plan posts of up to 4 images.
Sized, checked, published
Bluesky posts at the right size, in Mydrop
Mydrop shows every image in the real Bluesky preview and publishes text, images and video to Bluesky on time.
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Questions
Bluesky image sizes, answered
A square, such as 1000 × 1000 or 400 × 400 pixels, under 1 MB. Bluesky shows it as a circle.
Any ratio works; 16:9 (1600 × 900) and squares are safe choices. Each image must stay under 2 MB.
Up to 4 images. Bluesky's protocol added a 10-item gallery in June 2026, but plan for 4 until the app shows galleries everywhere.
Yes. No signup, no watermark, no limit, and your photo never leaves your device.
Size it here. Post it to Bluesky with Mydrop.
Preview, approve and publish every Bluesky post at the right size. Free to start.
