HumanizeAI vs Undetectable AI: Feature Facts, No Spin

The short version

Undetectable.ai is the established name in this niche: single-purpose, long track record, published API. HumanizeAI's case rests on three verifiable things: a live AI-detection score with every rewrite, a larger free tier (150 uses a month with a free account, 3 a day with none), and grammar, plagiarism, and citation tools inside the same subscription.

If you arrived here looking for a replacement rather than a side-by-side, the undetectable AI alternative page covers that angle, including who should stay put.

Who should pick Undetectable.ai

Pick Undetectable.ai if track record is your deciding factor. It has been the category's reference brand for years, it publishes an API with an established integration ecosystem, and a tool that many people have already vetted carries real value when you have no time to test.

Teams already paying for it and satisfied with results have no urgent reason to switch. Switching costs are real, and 'works fine' is a legitimate state to stay in.

Who should pick HumanizeAI

Pick HumanizeAI if you want to see scores while you work instead of submitting and hoping. Every rewrite shows an AI-likelihood number broken into burstiness, vocabulary diversity, and perplexity, so a weak rewrite is visible before it costs you anything.

Pick it for free-tier volume: 3 anonymous uses a day, or 150 a month with an email signup - enough to humanize several full articles monthly without paying. Pro is $19/month for 3,000 uses with Frozen Keywords and Writing Style.

And pick it if you currently pay separately for grammar, plagiarism, or citation tools: all three are bundled, which can retire a second subscription. There is an API as well, documented at api docs, if you integrate rather than paste.

The numbers we can publish

On June 11, 2026 we ran three ChatGPT-written passages through HumanizeAI in balanced mode and scored each on our built-in detector before and after. An essay paragraph fell from 99/100 to 1/100. A blog intro went 99 to 15. A marketing email went 99 to 14.

Method and settings live on the methodology page, and the same protocol produced the dated per-detector runs on our Turnitin and GPTZero pages.

We have not run Undetectable.ai's output through our detector or any other, so this page contains no numbers for it. That is deliberate. Invented benchmarks are how comparison pages lie, and a benchmark we didn't run is invented by definition.

Pricing structure, without competitor numbers

HumanizeAI's prices are ours to quote: free tier as above, then Pro at $19/month for 3,000 uses, Business at $49/month for 10,000, Enterprise at $199/month for 100,000.

We are not quoting Undetectable.ai's prices. Competitor pricing shifts with promotions, word-count tiers, and annual-versus-monthly toggles, and a stale number on our page would mislead you in whichever direction it is wrong. Open undetectable.ai's pricing page and compare against the numbers above on the same day you decide.

Limitations of this comparison

• No output benchmark. The honest head-to-head - identical passages through both engines, scored on third-party detectors - is a test we have not run.
• Our published scores (99 to 1, 15, and 14) are from our own detector and dated June 11, 2026. Engines and detectors both update; the tested rankings page carries our current test log.
• Feature lists drift. Undetectable.ai ships changes like anyone. Verify anything load-bearing on its own pages before deciding.