AI Humanizer Pricing Compared: 8 Tools in 2026

Price is only half the decision. For features and how the tools differ, start with Best AI Humanizers 2026, then come back here for the cost-per-word math.

Most AI humanizer pricing pages are hard to compare, and not by accident. Some count words, some count "requests", one splits words into two types, and several show annual-billing prices by default, so the headline number is roughly half of what a month-to-month subscriber pays. We went through the pricing pages of eight popular humanizers in September 2026 and put the numbers side by side.

Full disclosure: I work on SupWriter, so read this with that bias in mind. Every competitor figure below comes from that vendor's own pricing page, checked in September 2026. Prices change often, so confirm on the vendor's page before you pay. SupWriter figures are US list prices; student, regional and promotional discounts exist. And where SupWriter comes out more expensive (it does, on raw cost per word), we say so.

The Complete AI Humanizer Price Table (2026)

Here's the side-by-side for each tool's entry plan.

Competitor figures: vendor pricing pages (Undetectable AI, Humbot, WriteHuman, Phrasly, JustDone, QuillBot, NaturalWrite), checked Sept 2026. Humbot's page opens on its Yearly toggle, so the $7.99 it shows first is the annual-billing rate; month to month, Basic is $11.99. QuillBot's page shows only the annual rate, which it labels 58% off. Phrasly's page shows the annual rate by default; see the Phrasly note under free tiers.

Three things jump out. First, most entry plans sit between about $8 and $20 a month, but what that money buys varies enormously. Second, allowances are counted differently: SupWriter, Undetectable AI and NaturalWrite count words per month, WriteHuman counts requests, Humbot splits "Basic" and "Advanced" words, and Phrasly advertises unlimited humanizations with a per-process cap. Third, several vendors lead with annual-billing rates, which roughly halves the number you see first.

That's why cost per word matters more than the sticker price.

Cost Per Word: The Real Metric That Matters

Monthly price is a vanity number. What matters is how much you pay per thousand words you can actually process. Here's that figure at list price, on monthly billing, for plans that publish an allowance:

On annual billing the order holds. SupWriter drops to $1.00 per 1,000 words on Basic and $0.67 on Pro or Ultra; Undetectable AI runs from $0.50 on its 10K plan to about $0.43 on its 50K plan.

So, plainly: SupWriter is not the cheapest humanizer per word. Undetectable AI costs about half as much per word at the entry tier and roughly 30% less at higher volumes, and WriteHuman's request-based plans can be cheaper still if your requests are long. NaturalWrite's first three tiers are priced identically to SupWriter's. Phrasly, JustDone and QuillBot don't publish a monthly word allowance for humanizing, so their cost per word depends entirely on how much you use them.

A few things the per-word number hides:

• Per-request caps. SupWriter Basic caps each request at 500 words (Pro 2,000, Ultra 5,000). Humbot's humanizer caps at 500 words and WriteHuman Basic at 600. If you routinely paste 2,000-word essays, a low cap means splitting the text into chunks and checking that the joins still read smoothly.
• What the allowance covers. On SupWriter, humanizing costs 1 credit per input word, paraphrasing and grammar cost 1 credit per output word, and AI detection in the web app is free on paid plans. Other tools bundle these differently. How SupWriter credits work has the details.
• Request-based limits cut both ways. WriteHuman's 80 requests are cheap per word only if you use most of the 600 words each time. Short requests burn through the allowance fast.
• Word types. Humbot's plans split "Basic" and "Advanced" words, so check which engine you'll actually use before comparing.
• Annual lock-in. Annual billing halves the price for most tools here, but you pay for the year upfront. Choose it once you're sure the tool fits.

SupWriter Pricing Breakdown

Alright, let's turn the microscope on ourselves. Here's what SupWriter's pricing looks like at list price:

Basic: $9.99/month, or $4.99/month billed annually ($59.88/year)

• 5,000 words per month, up to 500 words per request
• AI humanizer, paraphraser and grammar checker
• Built-in AI detector, free in the web app on paid plans
• Chrome extension and MCP access; no developer REST API

Pro: $19.99/month, or $9.99/month billed annually

• 15,000 words per month, up to 2,000 words per request
• Everything in Basic, plus the advanced humanization engine, Writing DNA voice matching and fine-tuning sliders
• Developer REST API access (which the sw command-line tool uses)
• Extra credits available to buy

Ultra: $39.99/month, or $19.99/month billed annually

• 30,000 words per month (annual plans get 360,000 words upfront), up to 5,000 words per request
• Everything in Pro, plus priority support

Annual billing halves the monthly price on every plan, and annual subscribers get their 12 months of credits upfront. At annual list prices, that's $1.00 per 1,000 words on Basic and $0.67 on Pro or Ultra. The editor works in 50+ languages.

The free tier is 300 words in total. It's a one-time allowance, not a monthly one, and it needs a free account (sign-in) but no credit card. That's enough to humanize a paragraph or two and decide whether you like the output. It won't cover a full essay, and we're not pretending otherwise.

Where SupWriter earns its price is the bundle, not the per-word rate. The humanizer, detector, paraphraser and grammar checker live in one editor, and the same account works in the Chrome extension, the iOS app and the MCP server. If you'd otherwise pay separately for a checker and a paraphraser, that matters. If you only need raw humanizing volume, it matters less.

One honest caveat on the detector: it's a pre-check based on one scoring model, not the detector your school or client uses. Results vary by detector, text length and topic, and no tool can guarantee an outcome. (How we test)

Undetectable AI: Cheaper Per Word Than SupWriter

Undetectable AI is probably the best-known name in this space. Its marketing is everywhere, its UI is clean, and on price it beats us.

Its pricing page lists four tiers from 10,000 to 50,000 words a month. The entry tier is $9.99 a month for 10,000 words, or $5.00 a month billed annually ($60 a year). The top tier is $42.50 a month, or $21.25 billed annually, for 50,000 words. That works out to $0.85–$1.00 per 1,000 words on monthly billing and roughly $0.43–$0.50 on annual billing: about half SupWriter's rate at the entry tier, and roughly 30% below it at higher volumes.

The free trial is limited to 250 words, a little less than SupWriter's 300. The pricing page also mentions a money-back guarantee; read its conditions on their site before you count on it.

If price per word is your deciding factor, Undetectable AI is the better deal on paper. The real choice is between a humanizer-first subscription and a bundle: SupWriter's plans include the grammar checker, paraphraser and in-app detector, and Pro and Ultra add an API. The fairest test is to run the same paragraph through both with their free allowances and judge the writing, not just the price.

The JustDone $2 Trial: Read the Renewal Price

This one is worth calling out, even though we're a competitor.

JustDone AI's pricing page leads with "7-day Access" for $2.00. The same card says it "auto-renews monthly $29.99". That's worth pausing on, because the same page lists JustDone's regular Pro Monthly plan at $19.99 a month and its Pro Annual plan at $9.99 a month ($119.88 a year). In other words, if you take the $2 trial and don't change plans, you renew at a higher monthly rate than if you'd simply bought the monthly plan.

JustDone's pricing page doesn't publish a word allowance, so we can't give you a cost per word. It does advertise "Easy plan cancellation". If you start the trial, set a reminder for day six, and read our guide on how to cancel JustDone before you need it. Our JustDone review covers the product itself.

JustDone isn't alone here: Phrasly also sells short, cheap access that rolls into a paid plan. Low-cost trials are fine. The thing to check, every time, is what they renew into.

Free Tiers Compared: Which Gives You Enough to Actually Test?

The real purpose of a free tier is letting you check whether a tool works for your writing before you commit money. Not all free tiers are created equal.

SupWriter: 300 words, one-time, free account required Three hundred words gets you one solid paragraph, maybe two short ones. That's enough to paste in AI-assisted text, humanize it, and run the result through the built-in detector as a pre-check. It needs a sign-in but no credit card, and it doesn't refill each month.

Undetectable AI: 250-word free trial A similar-sized, one-off sample. Enough for a quick quality check, not for real work.

WriteHuman: 3 free requests a month, up to 250 words each The most generous recurring free option we found: up to 750 words a month, and it resets. If you only humanize the occasional paragraph, this may be all you need.

Phrasly: no free plan Phrasly sells three-day access for $2.00 with unlimited humanizations (up to 50 uses a day, 800 words per process). Its pricing page says the trial continues at "$19.99 per month, billed annually", while the Unlimited plan itself is listed at $10.99 a month billed annually. That wording is confusing, so confirm what you'll be charged before starting. Our Phrasly pricing breakdown goes deeper.

Humbot: no free plan listed Humbot's pricing page lists paid plans only, from $7.99 a month billed yearly ($11.99 month to month), alongside a 30-day money-back guarantee. That's a form of try-before-you-commit, as long as you track the date.

QuillBot: free humanizer up to 125 words QuillBot's free plan includes its humanizer for up to 125 words, with limited usage. Premium ($8.33 a month billed annually) unlocks full access. The free limit is enough to get a feel, not to test a whole essay.

NaturalWrite: no free plan shown on its pricing page Its paid tiers mirror SupWriter's prices and word allowances, plus an Unlimited tier at $79.99 a month ($39.99 billed annually).

JustDone AI: $2 for 7 days, then $29.99/month As covered above, this isn't a free tier. It's a paid trial, and calling it "free" would be misleading.

The verdict on free tiers: WriteHuman has the most generous recurring allowance. SupWriter and Undetectable AI offer one-time samples of similar size, and QuillBot's 125 words is enough for a quick look. Whichever you try, test with your own writing, not a demo sentence.

Our Pick: Best Value AI Humanizer in 2026

We built SupWriter, so of course we'd like you to pick it. Factor that bias in. But the honest answer is that "best value" depends on what you're buying:

1. Lowest cost per word. Undetectable AI, especially on annual billing. If you need to humanize a lot of text and nothing else, it's the cheapest per word of the tools that publish a word allowance.

2. Heavy volume with long inputs. WriteHuman's request-based plans or Phrasly's Unlimited plan, if their per-request and per-process caps fit your documents.

3. One tool for the whole workflow. SupWriter. You pay more per word, but the plan includes the in-app detector, grammar checker and paraphraser, the editor works in 50+ languages, and Pro and Ultra add an API, with the Chrome extension, iOS app and MCP server on the same account.

4. Watch the renewal terms. A $2 trial that renews at $29.99 a month isn't a bargain if you forget about it.

Whichever you choose, run the same paragraph through two or three tools with their free allowances. Read the output for meaning and tone, then check it with the detector you actually care about. SupWriter's built-in detector is a quick pre-check based on one scoring model, not your school's detector, and no tool can guarantee a result.

For students who need a deeper look at the workflow, our guide on humanizing AI essays walks through the full process. If you're evaluating free tools specifically, check the free AI humanizer tools roundup.

Pricing pages change constantly. Read the billing terms, compare cost per word on the billing period you'll actually use, and test before you buy. That advice holds whether you end up choosing SupWriter or not.