Undetectable AI vs Humanize AI

The two entry tiers are almost identical in price and pool, so the arithmetic is short. Price is reported on this site and never scored.

Undetectable AI figures read on its pricing page on 9 November 2026; Humanize AI Pro figures read on its pricing page the same day. Two caveats attach. Humanize AI Pro prints yearly savings of $60, $120 and $360 beside its plans, which implies a higher month-to-month rate it does not show, so a monthly comparison runs one way only: Undetectable AI's $9.99 against nothing. And the one-cent gap at the entry tier is noise; the real difference is that Humanize AI Pro's $9.99 tier buys 25,000 words where Undetectable AI's $9.99 buys 10,000 for a single month.

Undetectable AI's trial is 250 words in total, checked on 8 November 2026, which is one long paragraph before the paywall. Humanize AI Pro's tool runs without an account behind a captcha, and its home page describes the free use as unlimited, read 9 November 2026; no per-run word cap is stated on either page read. For a reader who wants to paste a 400-word section and read the result before entering a card, only one of these two allows it.

The free tool has a catch worth naming. Humanize AI Pro's pricing page says every paid plan has "all modes and settings", read 9 November 2026, which means the free output may not come from the mode a paying user would choose. The vendor does not say which mode the free tool runs. The published method records which mode each tool opens on and runs the strongest documented mode as a second row, so a published run will show whether the free output and the paid output differ.

Undetectable AI prices by a word slider with the yearly toggle on by default, and 10,000 words is the lowest point, read 9 November 2026; the pricing page states no request cap at any point on the slider and names no modes. Humanize AI Pro's ladder adds features as it adds words: Standard at $9.99 billed annually gives 25,000 humanizer words, 12,500 paraphraser words, no cap per process, re-humanizing and selective rephrase; Unlimited at $29.99 removes the word caps, read 9 November 2026.

Selective rephrase is the control that separates the two ladders. A tool that rewrites one highlighted sentence lets a writer repair one clumsy line instead of rerunning a whole page and re-checking every claim in it. Undetectable AI's pages describe no equivalent, read 9 November 2026. Whether the control is worth $4.00 a month more than Lite depends on how often a first pass needs a second.

No peer-reviewed study has tested either product by name in a way this site could cite, so the research here is about the category. Krishna and colleagues reported that a paraphrase model dropped DetectGPT's detection rate from 70.3 percent to 4.6 percent at a 1 percent false positive rate (Krishna et al. 2023, arXiv 2303.13408, read 9 November 2026). Weber-Wulff and colleagues tested 14 detectors and found every one below 80 percent accuracy, with accuracy falling further on paraphrased text (Weber-Wulff et al. 2023, International Journal for Educational Integrity, read 9 November 2026).

Humanize AI Pro's home page names Originality.ai, GPTZero and Turnitin as detectors its output clears, read 9 November 2026. Turnitin's detector is not available to the public, so no vendor can show a Turnitin reading a reader can reproduce, and this site reports only what Turnitin publishes. Undetectable AI's pricing page makes no detector claim at all, which is the more modest position and no evidence either way.

Those studies measured detector readings, not whether the rewritten text kept the writer's claims. The method on this site weights meaning kept at 35 points of 100, errors introduced at 20, detector pass rate at 30 and limits and access at 15, and two editors rate every output blind against its input. When a run is published, this page gains meaning, error and per-detector fields for both tools. No detector score should be the only evidence in a misconduct case.