Hi! I'm Aryan, and I'm a high school student. I made Optimal because I kept seeing students run ChatGPT essays through "humanizers" so AI detectors wouldn't catch them. Normal detectors miss a lot of these, so I built a free tool that looks for the stuff humanizers leave behind.
Check an Essay for Free See an Example Result
Just paste an essay (at least 40 words) into the box on the home page and click Check Text. You don't need an account. Without one you get 5 free checks a day. If you make a free account, you get 10 a day, you can check up to 2,500 words at once, and your results get saved so you can come back to them.
You get a score from 0 to 100% for how likely it is that the essay went through a humanizer. But honestly, I think the more useful part is the highlights. Optimal marks everything it noticed right in the essay, like hidden characters, letters from other alphabets, mixed British and American spelling, stiff phrases humanizers like to use, and spots its AI review thought seemed off. You can hover over each highlight to see why it got flagged, so you can decide for yourself if it makes sense.
I ran 50 essays through humanizeai.pro. I used 4 of them to teach Optimal what that humanizer's writing looks like, then tested it on the other 46, and it caught 43 of the 46. It also caught every Grammarly-humanized essay I tried. It's weaker on personal stories like college essays, and some human writing that sounds really generic can score high too. I put every test result on the Test Results page, including the misses, because I think teachers should know that before trusting any detector.
A high score is a reason to look closer, not proof that a student cheated. If something gets flagged, I'd look at the student's earlier drafts (Google Docs keeps a version history), compare it to their other writing, or just talk to them about it. Someone who actually wrote their essay can usually explain it pretty easily.
I wrote a few guides that might help:
If you have feedback or ideas, I'd really love to hear them. My contact info is on the About page.