AI image detector by platform

Bluesky AI image detector: re-encoded uploads and labeler labels

The Bluesky app re-encodes images as JPEG before upload, which removes EXIF, XMP, C2PA and saved prompts, so an image saved from Bluesky normally carries no records and any AI label comes from a moderation labeler on the post, not from the file.

Platform behaviour as documented or widely reported in October 2026. Updated 2026-10-15.

Check the downloaded image Frequently asked questions

Code-drawn illustration for Bluesky — AI source type declared: where this record sits inside a PNG file and what the isGenAI report says about it. The picture is a code-drawn illustration.

What Bluesky strips and adds

A Bluesky developer wrote in the app’s GitHub issues in 2023 that EXIF is stripped whenever a photo is cropped or compressed, and an open 2026 issue states that all images are re-encoded as JPEG on upload, with metadata stripping as a side effect. The AT Protocol guide adds that CDNs may serve resized or transcoded versions of the stored blob. Other clients that post to Bluesky may handle files differently.

Labels on Bluesky come from moderation services: Bluesky’s own and independent labelers that users subscribe to, some of which, as widely reported, label AI-generated imagery. We found no Bluesky documentation of a built-in AI-generated label or of C2PA support as of October 2026.

What isGenAI shows for a Bluesky image

The AI image detector reads the file you upload: a C2PA manifest if one survived, the IPTC DigitalSourceType in XMP, AI statements in metadata, saved prompts in the AUTOMATIC1111, ComfyUI and InvokeAI formats, and matching copies by hash and perceptual fingerprint. A platform copy with none of these returns “no evidence found”, and the report says plainly that absence proves nothing about the author.

Record any labeler label on the post separately; it is a judgment by the labeling service you subscribe to, not a record inside the file.

What to do instead

Ask the poster for the original file, or trace the image to its first publication. The matching-copy check can tie a stripped Bluesky copy to an earlier file that still carried records.

Keep the post link with your check so a reviewer can see the labels you saw.

How to check an image from this platform

Note the platform’s own label or credential icon on the post before you download anything; it does not travel with the file.
Ask the poster for the original file, or trace the first upload. A platform download is a re-encoded copy on most services.
Upload what you have to the AI image detector and read the report. A stripped copy returns “no evidence found” honestly.
Use the matching-copy check: a hash or perceptual fingerprint match can tie the stripped copy to an original that still carried records.

Check the downloaded image

Frequently asked questions

Does Bluesky remove image metadata?

Yes, in the official app: images are re-encoded as JPEG on upload, which strips EXIF and other metadata, per Bluesky’s GitHub issues. Other clients may differ.

Does Bluesky label AI-generated images?

We found no built-in AI label documented as of October 2026. Independent labelers you subscribe to can add labels, and some label AI imagery, as widely reported.

Can isGenAI detect AI in an image saved from Bluesky?

Only through a matching copy, since the re-encoded file normally carries no records. Check the original file when you can get it.

Does Bluesky keep Content Credentials?

We found no Bluesky documentation of C2PA support as of October 2026, and re-encoding removes an embedded manifest.

Sources

Where a platform documents its behaviour, the vendor page is linked. Where it does not, the page says the behaviour is reported, not documented.