Bluesky Image Size Limit Checker
Drop up to 4 images. See which ones are over the limit, shrink them in your browser, and write alt text with a live count.
Bluesky image limits
Bluesky allows up to 4 images per post, each up to 2,000,000 bytes (about 2 MB), raised from 1 MB in April 2026. Alt text can run to 2,000 characters in the Bluesky app, double X's 1,000. Drop images below to check them. Oversized files are shrunk in your browser, and nothing is uploaded.
Drop up to 4 images here
The files stay on your device. There is no upload request in this page.
Bluesky image limits, and how X compares
Up to 4 images per Bluesky post, each up to 2,000,000 bytes. The size limit was 1 MB until April 2026.
| Limit | Bluesky | X |
|---|---|---|
| Alt text | 2,000 characters in the Bluesky app | 1,000 characters |
| Post text | 300 graphemes and 3,000 bytes | 280 weighted characters |
As of September 2026.
Post to Bluesky, X and LinkedIn from one draft
OpenTweet posts to X, Bluesky and LinkedIn from one draft or one API call. Bluesky connects over atproto OAuth, with no API key and no App Password.
7-day free trial, then from $11.99/mo. Bluesky and LinkedIn on every plan.
Bluesky Image FAQ
What is the Bluesky image size limit?
2,000,000 bytes per image, as of September 2026. Bluesky raised it from 1 MB in April 2026. A post can carry up to 4 images, and each one is checked against the limit on its own.
How many images can I add to a Bluesky post?
Up to 4. This checker takes 4 at a time for that reason, and ignores any extra files you drop.
What is the Bluesky alt text character limit?
Up to 2,000 characters per image in the Bluesky app. X's alt text limit is 1,000, so alt text written for Bluesky may need cutting before you reuse it on X. The counter under each image shows both.
Why does my file manager say the image is under 2 MB when this says it is over?
The limit is 2,000,000 bytes. Some file managers, Windows Explorer among them, count in units of 1,024 bytes, so they show a 2,050,000 byte file as about 1.96 MB. This checker compares the exact byte count.
How does this tool shrink an image?
It draws the image onto a canvas in your browser and re-encodes it as JPEG or WebP. It lowers the quality first, then scales the dimensions down, and keeps the first version that fits under 2,000,000 bytes. Transparent areas turn white in JPEG, an animated GIF becomes a still image, and metadata such as EXIF location is not carried over.
Is my image uploaded anywhere?
No. The file is read and re-encoded in this browser tab. There is no upload request in this page, which you can confirm in the network panel of your browser dev tools.
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