What "free" means here
- No sign-up and no limit. There is no counter. Add a folder if you like (up to 200 pictures on a page).
- It runs on your device. The detector model is downloaded once (57 MB) and your browser does the work, so there is no per-picture cost that would force a limit.
- We are paid by ads, and, like every tool on this site, the page sends a copy of each picture and its result to our server (see the privacy policy). Do not add pictures you would not want stored.
What you get for free
More than a score. The page first reads what the file says (prompt, ComfyUI workflow, Content Credentials, AI labels, the Stable Diffusion watermark), then camera records, then a detector model, the size and the noise. The first of these that settles the question decides the answer, so most "yes, AI" answers do not rest on a guess at all.
How to judge any free detector
Many free detectors show one confident number. Ask three things of any of them, including this one:
- Was it tested on pictures it did not train on? We held out whole generators and kinds of real picture.
- Does it say how often it is wrong? Ours: of the pictures scoring 80 or more, 89% were AI; under 35, 14% still were.
- Does it use the file? A pixel-only detector throws away the strongest evidence.
What free cannot fix
Nobody can read Google's SynthID or OpenAI's marks without their own tools, stripped files say nothing, and drawings fool detectors (ours called all five real anime pictures AI, so it gives no number for flat-color art). On our 249 test pictures the detector flagged 85% of AI and 25% of real. See the guide to free detector accuracy.
Frequently asked questions
Is there a catch?
The page shows ads, and it sends a copy of each picture and result to our server, as every tool here does. The detector itself costs nothing to run for you or for us.
Is a free detector as good as a paid one?
We have not tested paid ones. What we can say is how this one did: AUC 0.90 on our test pictures, against 0.63 to 0.72 for four other public models.
Why does it ask me to download 57 MB?
That is the detector model. It is saved in your browser, so it downloads once. A picture whose file already says an AI made it needs no download.