QuillBot's own plan pages read first-party

QuillBot AI humanizer and its free word limit, what Premium costs and the QuillBot humanizer alternative

The free tier is capped twice, and the second cap is the one QuillBot no longer puts a number on. Here is what its own plan table says, and how that wording has changed since August.

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The short answer

QuillBot's AI humanizer is free at quillbot.com/ai-humanizer, and its free tier carries two limits rather than one. Each free paste is capped at 125 words in QuillBot's US plan table through September and at 100 words in the copy served to us on October 6, and the number of uses is described only as "limited usage". The August copy gave a fixed daily count of uses, and QuillBot dropped that number in September. Premium starts at $8.33 a month billed annually and removes both, in QuillBot's words: "No word or usage limit". QuillBot makes no claim that its humanizer beats AI detectors, and it sells a detector of its own that reads up to 1,200 words per scan. So a free account will tell you a 1,200-word essay looks AI-written, then let you rewrite a paragraph of it at a time.

Every quotation below was read on the vendor's own page on the date shown beside it.

The plan table, not the marketing

What the QuillBot humanizer gives you, by tier

Six things worth knowing before you decide, read on QuillBot's own pages between August 22 and October 6, 2026.

What does the free QuillBot humanizer actually give you?

A paragraph at a time, and an allowance it no longer quantifies. In August the plan table on quillbot.com/premium gave a fixed number of uses per day alongside the 125-word cap. By late September the US copy read "125 words, limited usage", and the copy served to us on October 6 read "Humanize up to 100 words, limited usage". The per-paste cap is published. The daily allowance is not.

What does Premium remove?

The cap, in QuillBot's own words: "No word or usage limit". It also unlocks advanced humanizing, humanize history, and the ability to humanize inside ChatGPT and Gemini rather than tab-switching to the website.

What does Premium cost?

In US dollars, $8.33 a month billed annually ($99.95 a year), $19.95 billed monthly, or $39.95 billed quarterly. The annual plan is the one QuillBot pushes, labelled "Pay annually 58% off" on the copy served to us on October 6, 2026.

Does QuillBot also sell a detector?

Yes, at quillbot.com/ai-content-detector, free with a ceiling of "Up to 1,200 words per scan" and a stated "minimum of 80 words is required to scan". The same company sells you the rewrite and the checker.

How many languages does the humanizer handle?

Its page lists Spanish, German, French, Portuguese and four dialects of English (US, UK, AU and CA). That is a narrower spread than Grammarly offers but wider than most standalone humanizers in this market.

Is the basic and advanced split a real difference?

It is a paywall. QuillBot's own comparison lists "Basic humanizing" on Free and "Advanced humanizing" on Premium, and the tone-insight feature is labelled a Premium feature on the humanizer page itself.

Most write-ups of this tool quote the 125-word cap and stop there, which misses half the constraint. The word limit is per paste, and it has moved: 125 words in the US copies of QuillBot's plan table through September, 100 words in the copy served to us on October 6. The usage limit sits in the same row, and it used to be a fixed daily count until QuillBot replaced it with "limited usage" in September. So a free account rewrites a paragraph at a time, with no memory carried between passes, and an allowance you only discover by hitting it. For a paragraph in an email that is fine. For a 2,000-word article it is 16 or more separate pastes and a lot of stitching.

The same engine also turns up outside QuillBot. Scribbr's free humanizer embeds it with a 125-word box and no sign-up, which we cover in the Scribbr AI humanizer review.

QuillBot is careful about what it promises, and it deserves credit for that. There is no bypass claim anywhere on the humanizer page. What it advertises is that the tool was "trained on tens of thousands of human texts" and removes AI tells, and it lists concrete uses: resumes and cover letters that "feel generic", stiff phrasing in "emails, reports, or proposals", and content for search, where it notes that "Search engines can flag text that looks mass-produced by AI". That last one is the pitch closest to a business budget, and it is also the one where the free caps bite hardest.

The company is also unusually direct about the ethics, in a sentence buried under the tool: trying to pass off someone else's idea as your own, it says, is just as unethical when it has been reworded as when it was copied outright. We agree, and it is why every page here is aimed at making your own writing read as yours rather than at faking anybody else's.

1,200 words in, a paragraph out

QuillBot will scan more of your essay than it will rewrite

The same free account, two products, two very different ceilings.

Put the two free tiers side by side and the shape of the offer becomes obvious. The AI detector at quillbot.com/ai-content-detector accepts up to 1,200 words per scan and asks for at least 80, because short passages produce unreliable readings. The humanizer accepts 100 to 125 words per pass, with a usage allowance QuillBot does not quantify. One product is sized to read a whole essay. The other is sized to rewrite a paragraph of it.

That asymmetry is not a criticism, it is a business model, and it is a perfectly rational one. Diagnosis is cheap to give away because it creates the problem the paid product solves. It is worth naming because it changes how you should use the free tier: scan the entire document in one go, note which paragraphs come back flagged, and spend your free passes only on those. People who work the other way around, rewriting from the top and rescanning after every pass, run out of allowance somewhere around paragraph three.

The detector page carries two more lines worth keeping. QuillBot says that "when the result is unclear, our model tends to classify texts as human written, which reduces false positives", which is an honest description of a deliberate bias and a rare thing to publish. And it advertises a "99% detection rate, according to independent evaluations from RAID". RAID is a real benchmark, published at ACL in 2024 over more than six million generations, and its own paper concludes that detectors are easily fooled by adversarial attacks. Both statements can be true at once: high accuracy on clean machine text, much weaker performance on text somebody has since rewritten. That distinction runs through every number in this market, and we set it out in full in how AI detectors work and the AI detector false positive rate.

Six humanizers, honestly compared

QuillBot humanizer against the alternatives

Prices and quotations were read on each vendor's own page on the date in the first column. Where a vendor does not publish a number, this table says so rather than guessing.

Tool	Price and limits	What it says about detectors	Where it runs	Worth knowing
QuillBot AI Humanizer (Free)Checked Oct 6, 2026	$0. Each paste is capped at 100 to 125 words, and the number of uses is "limited usage", a figure QuillBot no longer prints.	Makes no bypass claim. It returns a human score rather than a promise.	quillbot.com/ai-humanizer in a browser.	Advanced humanizing, tone insights, humanize history and the ChatGPT and Gemini integrations are all withheld from this tier.
QuillBot PremiumChecked Oct 6, 2026	$8.33 a month billed annually ($99.95 a year), $19.95 monthly or $39.95 quarterly. The humanizer becomes "No word or usage limit".	Same as free. QuillBot sells the detector too, and does not claim one beats the other.	Web, apps, browser extensions, and inside ChatGPT and Gemini.	Bundles paraphrasing, grammar, summarizing, citations and a plagiarism check capped at 25,000 words a month.
Grammarly HumanizerChecked Aug 20, 2026	Free tier with an allowance Grammarly does not publish as a number, then "Upgrade to Grammarly Pro to unlock the full Humanizer experience".	States on its own page: "This tool is not intended to bypass AI detectors."	grammarly.com/ai-humanizer, plus an agent inside Grammarly docs and Superhuman Go.	Six languages and a custom voice built from "a writing sample of 200 words or more".
OpenAI AI HumanizerChecked Aug 19, 2026	Bundled with a ChatGPT account.	Makes no detector claim at all. Three modes: "Shorten text", "Improve clarity", "Make it original".	chatgpt.com/writing/ai-humanizer.	Carries the notice "Chats may be reviewed and used to improve our AI models", which rules it out for confidential drafts.
Undetectable.aiChecked Aug 19, 2026	$5.00 a month billed yearly ($60/yr) for 10,000 words, $9.50 a month yearly for 20,000.	Sells directly on clearing detectors and runs its own multi-detector check.	Web app, browser extension, and a REST API on every paid tier.	Cheapest annual entry price here, and the only one with API access on the entry plan. That genuinely beats us.
Undetected.ai (us)Checked Aug 22, 2026	From $24 a month yearly for 100,000 words, $49 for 300,000, $99 for 1,000,000. Accounts are open.	One rewrite of your own text, with our AI-pattern score before and after and the reasons behind it. No promise about any outside detector.	Web app. No public REST API on the self-serve plans.	Runs are saved to your account history so you can come back to them, and you can delete any of them. See the privacy page for what our AI model provider does with the text in transit.

Read the table by column rather than by row. The price column separates free-with-caps from paid, and in this category the caps decide more purchases than the accuracy claims do. QuillBot publishes its limit precisely, which is more than Grammarly does: Grammarly gives its humanizer a free tier and never says how much of it you get. Precision is worth something even when the number is small.

The detector column is the one that decides purchases for anyone whose work gets scored. Three of the six explicitly decline to promise anything, one makes no claim at all, and two sell on clearing checkers. If you are choosing between free options, that column is telling you they are solving a readability problem rather than a scoring one, and they are saying so themselves. The full head-to-head between the two free giants is on QuillBot humanizer vs Grammarly humanizer, and the Grammarly side in depth on the Grammarly AI humanizer page.

The last column carries what each vendor would rather you skimmed. For OpenAI it is the data notice. For Undetectable.ai it is genuinely in their favor: cheaper than us annually, with a REST API on every paid tier where ours comes with Scale only, and if programmatic access on a small budget is the requirement they are the honest recommendation. Their full ladder is on Undetectable.ai pricing. The wider paid field is compared on the best AI humanizer page, and the direct swap on the QuillBot alternative page.

How to use it properly

Four steps, in the order that actually works

Step 1

Count the words before you count the tools

A 1,500-word piece is 12 or more separate passes on the free tier, at 100 to 125 words each, against a usage allowance QuillBot does not publish. If that describes your normal week, the free tier is not a cheaper option, it is a different product.

Step 2

Scan the whole document, rewrite the flagged part

QuillBot's detector reads up to 1,200 words at a time and asks for at least 80. Scan first, find the paragraphs that score high, and spend your short free passes there rather than rewriting text that already reads fine.

Step 3

Watch the seams between passes

Stitching a long piece out of separate short rewrites is where tone drifts. Each pass has no memory of the last one, so paragraph four can come back in a register that paragraph three never used. Read the joins out loud.

Step 4

Decide what the document is actually for

A newsletter nobody scores and a paper going into Turnitin are different jobs. If a checker sits at the end of the pipeline, size your tool to that, and be clear about what any vendor can honestly promise.

Step three is where most of the complaints about this tool come from. Search the product name alongside the phrase "doesn't work" and you find people describing a rewrite that reads worse than the original, and the usual cause is stitching. Each short free pass is independent. Paragraph one comes back conversational, paragraph four comes back formal, and the piece as a whole ends up less consistent than the machine draft it started as. Uniformity is what classifiers measure most reliably, but a document that lurches between registers reads badly to humans, which is the audience that actually matters. The mechanism behind both halves of that is set out in whether humanized text can still be detected.

Who should use which

Six situations, and the right tool for each

If the first one describes you, stop reading and go use the subscription you already have.

You already pay for QuillBot Premium

Then use it. At $8.33 a month billed annually it bundles paraphrasing, grammar, summarizing, citations, a plagiarism check and an unlimited humanizer. Paying twice for overlapping rewrites makes no sense.

You paste short passages occasionally

The free tier is genuinely useful at 100 to 125 words a pass. An email, an abstract, a LinkedIn post, a paragraph that reads stiff: all of those fit inside one pass with room to spare.

You write long documents every week

This is where the free tier stops being free in any useful sense. A 2,000-word draft is 16 or more separate pastes against an allowance QuillBot does not publish, which means rationing your own writing around somebody else's counter.

Your work gets scored by a detector

QuillBot does not claim its humanizer beats detectors, and neither does Grammarly, which says so in one sentence on its own page. The free tools are solving a readability problem. Say that out loud before you pick one.

The text is confidential

Read each vendor's data notice before the price. OpenAI's humanizer states that chats may be reviewed and used to improve its models. For a client deliverable or unreleased research, that notice is the whole decision.

You need programmatic access

QuillBot does not publish a self-serve humanizer API. Undetectable.ai puts a REST API on every paid tier and WriteHuman prices one by word. Ours is part of the Scale plan only, so on a small budget the other two are cheaper routes in.

Students sit in the hardest position on this list, because the checker their work meets is one they cannot run and whose output they never see. Turnitin shows its AI writing indicator to instructors and administrators, not to students, and suppresses any reading between 1 and 19 percent entirely. That is a governance problem before it is a writing problem, and it has its own page in the AI humanizer for students. Whether QuillBot's own paraphraser survives that checker is covered in does Turnitin detect QuillBot.

Teams publishing at volume have the opposite problem, which is consistency across several writers rather than a limit on one account, and that is covered on the AI humanizer for content teams page. Anyone working from a ChatGPT or Claude draft specifically will find the model-level tells in the ChatGPT humanizer and the Claude AI detector page.

Before you switch tools

Three things we will not tell you

That QuillBot's humanizer is bad. It is not. It is a competent rewriter inside a suite that also covers paraphrasing, grammar, summarizing, citations and plagiarism, for $8.33 a month billed annually, and it is honest about what it does not promise. If you already pay for Premium, the correct answer to this entire page is to keep using what you have.

That any tool guarantees a detector score. Not us, not QuillBot, not the vendors publishing bypass percentages. GPTZero states that its classifier "is not trained to identify AI-generated text after it has been heavily modified after generation", and that sentence is the entire honest case for this category: heavy editing changes what a classifier sees, and nobody can convert that into a promise about your specific document.

That a rewrite fixes a weak draft. A humanizer changes rhythm and register. It does not add evidence, repair a thin argument or check a fact. If the draft contains an invented citation, the rewritten version contains the same invented citation in better prose, which is worse, because it now reads convincingly.

What it costs to move

Sizing a paid plan against what you actually publish

Start from the per-paste cap, because it converts cleanly into a decision. At 100 to 125 words a pass, a 1,500-word essay is 12 or more separate passes on the free tier, each one rewritten without knowing what came before, and QuillBot no longer says how many passes you get. Count the words you rewrite in a normal week. If it is the odd paragraph, the free tier will hold. If it is whole documents, you are already paying in tab-switching and split paragraphs rather than in dollars.

QuillBot Premium at $8.33 a month billed annually is the obvious first upgrade, and it buys an uncapped humanizer plus five other tools. It is also the only mainstream humanizer that publishes no word limit at all, which is rarer than the marketing in this category suggests. Undetectable.ai starts lower at $5.00 a month billed annually for 10,000 words and puts a REST API on every tier, so on entry price alone they win. Our own plans are set at $24 a month for 100,000 words, $49 for 300,000 and $99 for 1,000,000, billed annually, which is ten times their entry allowance on Starter and $0.24 per 1,000 words. Accounts are open and free to create, and the humanizer works today. You pick a plan on our pricing page and pay by card in a couple of clicks. Where we differ is our own AI-pattern score on screen, with the reasons behind both numbers.

Frequently asked

QuillBot humanizer questions, answered

Is QuillBot humanizer free?

There is a free tier and it is capped twice over. Each paste is limited to 125 words in QuillBot's US plan table through September and to 100 words in the copy served to us on October 6, and the number of uses is "limited usage". The August copy of that table gave a fixed daily count of uses, and QuillBot stopped printing it in September. Premium removes both limits, which QuillBot describes as "No word or usage limit", from $8.33 a month billed annually.

Does QuillBot humanizer bypass Turnitin?

QuillBot does not claim it does, and nobody outside Turnitin can verify a pass rate. Turnitin sells only to institutions, publishes no public API, and states that it trains against rewriting tools but will not name them. Treat every specific Turnitin bypass percentage in this market as a number the seller produced on a test nobody else can repeat.

Can QuillBot humanizer be detected?

Rewritten text is still scored like any other text, so yes, it can still be flagged. GPTZero states that its classifier "is not trained to identify AI-generated text after it has been heavily modified after generation", which is the honest mechanism behind this whole category. Light polishing rarely moves a score; heavy rewriting sometimes does.

Why is the QuillBot humanizer not working?

Almost always one of three limits rather than a fault. You have passed the 100 to 125 word cap in a single paste, you have used up the free allowance QuillBot calls "limited usage", or you are trying to use advanced humanizing, humanize history or the ChatGPT and Gemini integrations, which QuillBot reserves for Premium.

What is the difference between QuillBot basic and advanced humanizing?

Access, set by plan. QuillBot's own feature comparison lists "Basic humanizing" against Free and "Advanced humanizing" against Premium, and the tone-insight check on the humanizer page is marked a Premium feature. QuillBot does not publish what changes in the model between the two.

How accurate is the QuillBot AI detector?

QuillBot advertises a "99% detection rate, according to independent evaluations from RAID". Worth knowing what RAID is: a 2024 benchmark of over six million generations whose own paper concludes that detectors are easily fooled by adversarial attacks. The benchmark measures clean AI text, not text somebody has rewritten.

Does QuillBot have a humanizer API?

Not a public self-serve one. QuillBot ships browser extensions, desktop and mobile apps and integrations into ChatGPT and Gemini on Premium, but publishes no humanizer REST endpoint you can buy. If programmatic access is your requirement, Undetectable.ai and WriteHuman both sell one, and Undetected.ai includes one on the Scale plan.

Is QuillBot Premium worth it?

It depends entirely on volume. If you regularly rewrite whole essays or articles, a 1,500-word piece is 12 or more separate free passes, and $8.33 a month billed annually for an uncapped humanizer plus paraphrasing, grammar, citations and a plagiarism check is good value. If you only polish the odd paragraph, the free tier does the job.

What is a QuillBot humanizer alternative?

They split by what you actually need. Grammarly is the closest free equivalent and states its humanizer is not meant to bypass detectors. OpenAI ships one inside ChatGPT with a data-use notice attached. Undetectable.ai is the cheapest paid option at $5.00 a month billed yearly. We show our own AI-pattern score before and after, with the reasons, and do not claim a result from any detector.

Does QuillBot store the text I paste?

QuillBot does not answer that in the plan table, so check its privacy policy for your own use case rather than trusting a summary. It is the question worth asking of every rewriter, ours included. Our answer: we save your run to your account history so it is there when you come back, you can delete it, and we delete it for you after 90 days. Our privacy page also states plainly what our AI model provider may do with the text while it is processing it.

Keep reading

When a paragraph at a time stops working

Paste a full paragraph and watch which parts change. If QuillBot's free tier already covers what you write, keep your money.

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