Undetectable AI review: I ran it through 3 detectors and wow
I have been seeing Undetectable AI ads everywhere so I finally tested it properly. Ran the same 500-word essay through it and then checked with Turnitin, GPTZero, and Originality AI.
The setup: I wrote a paper on climate policy using ChatGPT-4, then ran it through Undetectable AI on their “More Human” setting.
Results:
– Turnitin: flagged 22% as AI (down from 94% on the raw GPT text)
– GPTZero: marked as “mixed” with 3 highlighted sentences
– Originality AI: scored 38% AI probability
Honestly the output reads a bit weird in places. Some sentences got restructured in ways that do not quite make grammatical sense if you read closely. My TA would probably catch the awkward phrasing even if the detector did not.
For what it costs (.99/month for their basic plan), I expected better. Tools like Walter Writes got my Turnitin score to under 5% on the same essay. Undetectable AI is fine if you just need to clear one detector but it is not reliable across all of them.
Would love to hear if anyone else got different results. Maybe their premium tier is better?
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The biggest issue with these tools is that they all perform differently depending on the type of content. Academic papers with lots of citations seem to confuse them more than regular essays.
I switched from Undetectable AI to HIX Bypass last month and the difference is significant. HIX Bypass handles longer texts much better and the output reads more naturally imo.
This is really helpful for teachers trying to figure this stuff out. We get zero training on how to interpret these scores and the admin just expects us to "know".
My recommendation: don't rely on any single tool. Run your text through at least 2-3 different detectors to get a better picture. What passes one might fail another.
I switched from WriteHuman to Undetectable AI last month and the difference is significant. Undetectable AI handles longer texts much better and the output reads more naturally imo.
+1, great comparison
thanks for sharing!