Grammarly AI Humanizer Review: What It Does, and What Our Test Showed
Grammarly now sells a humanizer, an AI detector, and, through its parent company, GPTZero. We tested its free humanizer on September 24, 2026 and published the unedited scores. Want to compare on your own text? Humanit's humanizer is right above.
Grammarly's AI humanizer is a free web tool that rewrites AI text to sound more natural; a free account adds four preset voices, a custom voice and six languages. Grammarly says it is not intended to bypass AI detectors. In our one-paragraph test its rewrite scored as human on ZeroGPT but was still flagged by our own detector.
How it works
- 1Paste your text. Drop in AI output from ChatGPT, Gemini, or Claude.
- 2Pick a tone. Choose from 10 modes — Casual to Ultra.
- 3Humanize. Get natural, human-sounding writing in seconds.
- 4Verify. Check the result with the built-in AI detector.
What Grammarly's AI humanizer is
The humanizer on grammarly.com is free and runs without an account, offering what Grammarly calls basic humanization. Signing up for a free Grammarly account unlocks the Humanizer agent: four preset voices, a custom voice profile built from a sample of your writing, and humanizing in six languages — English, Spanish, French, German, Portuguese and Italian. Grammarly Pro unlocks what it calls the full Humanizer experience. It sits inside the same product family as Grammarly's grammar checker, plagiarism checker, AI detector and Authorship.
Grammarly says it is not for bypassing detectors
Grammarly is unusually direct about this. Its own FAQ says the humanizer is not intended to bypass AI detectors; it is meant to make AI-assisted writing clearer and more natural, and Grammarly encourages clearly acknowledging AI assistance in academic or professional work. It points users towards its transparency features — Authorship, which records how text entered a document — for situations where the source of the writing matters. That stance is worth taking at face value: a humanizer from the company that also sells an AI detector and owns GPTZero is not positioned as a way around them.
How we tested it
On September 24, 2026 we took one 124-word paragraph about remote work, written by an AI model in the stock style detectors look for, and ran it once through Grammarly's free humanizer with no account. We then scored the original and Grammarly's rewrite on every detector we could use for free without signing up. Each tool ran once; nothing was retried, cherry-picked or edited. Grammarly's detector and GPTZero each allowed one free scan before asking us to sign up, so they scored only the original. One paragraph on one day is an anecdote, not a benchmark — treat the table below that way.
What the results do and do not show
Grammarly's rewrite scored 0% AI on ZeroGPT, the only independent detector we could run on it, while the original scored 100% there. That is a real result. The same rewrite was 38% longer (124 words became 171), switched to British spelling, and kept stock transitions such as 'Furthermore' and 'It should, however, be pointed out' — which is why Humanit's detector still rated it likely AI at 75, the same as the original, and named those exact phrases. Two detectors, opposite verdicts on the same text: that disagreement is the most useful finding here, and it is why no single score tells you what Turnitin, which nobody outside an institution can run, would say.
Can Grammarly's detector catch its own humanizer?
We could not test it: Grammarly's detector asked us to sign up after one free scan, which went to the original paragraph. It is the obvious open question about a company selling both tools, and Grammarly's answer, in effect, is that it does not intend the humanizer to be used that way. If you have a Grammarly account, scanning your humanized draft with its detector takes seconds — and whatever it says, Authorship still records how the text entered your document.
Who should use it, and where Humanit is different
Grammarly's humanizer suits people already writing in Grammarly who want AI-assisted drafts to read more naturally, in one of six languages, with Authorship available if they need to show their process. Humanit is built the other way round: the humanizer and the detector sit side by side, and the detector tells you why a passage reads as AI, phrase by phrase, instead of handing you one number. That is the part a humanizer on its own cannot give you. Humanit's humanizer has ten modes, from Casual to Ultra, rewrites in your own voice with Match my style, and is priced in words: 300 free words a month, plans from $9.99, and one-time top-ups that never expire.
Try it on your own paragraph
The fairest test is the one you run on your own writing. Paste a paragraph into the Humanit humanizer at the top of this page, pick a mode, then check the result with the free AI detector — no account needed for checks up to 300 words — and read which phrases it still flags. Rewrite those in your own words, re-check, and keep your drafts either way. Whatever tool you use, the goal Grammarly describes is the right one: writing that reflects your own thinking and voice.
Who it's for
| Grammarly AI humanizer | Humanit | |
|---|---|---|
| Free without an account | Yes, basic humanization | No: free account, 300 words a month |
| Styles | 4 preset voices + custom voice (free account) | 10 modes, Casual on the free plan |
| Languages | 6: EN, ES, FR, DE, PT, IT | English-first |
| Paired detector | Grammarly AI detector (up to 2,000 words a scan) | Built-in detector, 300 words a check without an account |
| What it says about detectors | "Not intended to bypass AI detectors" | No pass promised; check the result yourself |
| Process evidence | Authorship records how text was written | None |
| Version | Words | Grammarly detector | GPTZero | ZeroGPT | Humanit detector |
|---|---|---|---|---|---|
| Original (AI-written) | 124 | 100% AI | AI 100%, highly confident | 100% AI | 75, likely AI |
| Grammarly AI humanizer (free) | 171 | Sign-up required | Sign-up required | 0% AI | 75, likely AI |
| Version | Text |
|---|---|
| Original (AI-written) | Remote work has fundamentally transformed the way organizations operate in today's rapidly evolving landscape. By leveraging digital collaboration tools, companies can tap into a global talent pool while significantly reducing overhead costs. Moreover, employees often report improved work-life balance, as the elimination of daily commutes allows them to allocate more time to personal pursuits. However, it is important to note that remote work also presents unique challenges, including feelings of isolation and difficulties in maintaining clear communication across time zones. To address these issues, successful organizations prioritize regular virtual check-ins, foster a strong digital culture, and invest in robust project management platforms. Ultimately, the future of work will likely be hybrid, combining the flexibility of remote arrangements with the collaborative energy of in-person interaction. |
| Grammarly AI humanizer (free) | Remote work has completely changed the way organisations function in the quickly changing environment we now live in. Through the use of digital collaboration tools, businesses are able to draw on a global pool of talent at the same time as greatly cutting their overhead expenses. Furthermore, employees generally say that they have a better work-life balance since not having to make the daily commute enables them to spend more time on things related to their personal lives. It should, however, be pointed out that remote work also brings with it its own set of problems, such as a sense of isolation and difficulties in keeping communication clear when there are different time zones involved. In order to overcome these problems, effective organisations make it a priority to have regular virtual meetings, build a strong digital culture, and put money into reliable project management systems. In the end, the future of work is likely to be hybrid, mixing the flexibility of working from home with the collaborative atmosphere of face-to-face interaction. |
Frequently asked questions
Is Grammarly's AI humanizer free?
Yes. The humanizer on grammarly.com offers basic humanization without an account. A free Grammarly account adds the Humanizer agent with four voices, a custom voice and six languages, and Grammarly Pro unlocks the full version.
Does Grammarly's AI humanizer bypass AI detectors?
Grammarly says it is not intended to. In our one-paragraph test its rewrite scored 0% AI on ZeroGPT but was still rated likely AI by our detector. Detectors disagree, and no humanizer can promise a pass on every one — including Turnitin, which cannot be tested publicly.
Can Grammarly's AI detector detect its own humanizer?
We could not test that without an account, because Grammarly's detector asked us to sign up after one free scan. Grammarly positions the humanizer for clarity rather than evasion, and Authorship records how text entered a document regardless of rewriting.
Does Grammarly's humanizer make text longer?
In our test, yes: a 124-word paragraph came back at 171 words, about 38% longer, with British spelling. One test is not a rule, so check the length of your own output.
Is using Grammarly's AI humanizer cheating?
It depends on your institution's rules. Grammarly itself encourages clearly acknowledging AI assistance in academic or professional work, and points to its Authorship feature for showing how a document was written.
What languages does Grammarly's humanizer support?
Six with a free account: English, Spanish, French, German, Portuguese and Italian.
What is a good alternative to Grammarly's AI humanizer?
Humanit pairs a humanizer with ten modes with a free AI detector that shows which phrases read as AI, so you can see what to fix rather than trusting one score. A free account includes 300 words a month, and the detector needs no account for checks up to 300 words.
Will my text be used to train AI?
No. Your text is sent to the model only to produce your result and is never used to train any AI. No content is stored beyond the request.
Does it keep my original meaning?
Yes. Humanit preserves your facts, numbers, names, and citations while changing the phrasing and structure. It never invents new claims.