Copyleaks vs ZeroGPT

Decision matrix - who fits which side

Check = clear edge. Tilde = capable but not the stronger pick. Cross = outside the model.

Strengths & tradeoffs

Both tools flag likely AI-generated text as their core function, but each was built for a different buyer, and each wins rows the other doesn’t.

Ratings & track record

Both tools carry rating uncertainty, and the same uncertainty in the same direction. Copyleaks’ G2 presence is internally inconsistent, with two separate product pages reporting 4.3 to 4.5/5 across 24 to 41 reviews for what appears to be the same underlying product line, and G2 blocks automated verification, so neither its figures nor ZeroGPT’s 4.1/5 could be independently confirmed for this comparison. Treat every G2 number on this page as reported rather than checked.

The verified numbers tell a more useful story, and it is not the flattering one for either vendor. On software directories, where buyers evaluate features, Copyleaks holds 4.4/5 from 91 Capterra reviews and ZeroGPT is reported at 4.1/5 on G2. On Trustpilot, where end users land after a verdict goes against them, Copyleaks sits at 2.3/5 from 333 reviews and ZeroGPT at 1.3/5 from 107. ZeroGPT’s score is the worse of the two, but Copyleaks’ is poor in absolute terms and rests on three times the sample, so the “Copyleaks has the clean reputation” framing does not survive contact with the data. Both review pools are dominated by the same complaint: human-written work flagged as AI.

Neither vendor’s accuracy positioning survives independent testing either. Copyleaks advertises over 99% accuracy and a .03% false-positive rate; independent runs measured 90.7% accuracy on a 3,000-sample benchmark (77% to 96% across other studies) with false positives of 5.26% to roughly 9%, and University of Adelaide research found detection probability falling from 85.2% to 73.1% once a human edited the text. ZeroGPT publishes no accuracy figure at all on its current site, and the 98%-plus number circulated by review aggregators does not appear there; independent testing puts it at 67% to 85% accuracy with false-positive rates of 14.6% to 33%, including 26.4% across 37,874 verified human essays. One of the Copyleaks benchmarks cited here is published by GPTZero, a direct competitor to both products, and should be read with that bias in mind.

The honest read: Copyleaks is the more verifiable company and the more accurate detector on the tests available, with real compliance certification and a real education footprint. ZeroGPT is cheaper at every tier, ships far more bundled tools, and gives away a usable free check with no card. Both should be treated as advisory signals rather than evidence, especially in any setting where a false positive carries a consequence for a student or a writer.

Both tools’ data is sourced from publicly available information as of 29 July 2026. All pricing, compliance, LMS and Trustpilot figures above were read off the primary source directly. G2 ratings for both products could not be verified because G2 blocks automated access, and are labelled reported wherever they appear. Prices and ratings move, so re-check copyleaks.com/pricing and zerogpt.com/pricing before purchase. This comparison is independent; we take no affiliate or referral fees from either vendor.