Independent review · prices read on grubby.ai October 6, 2026
Grubby AI review of Grubby AI humanizer pricing, 4-week billing and the refund question
Grubby AI is an English-only humanizer sold in four plans, from $8.99 a month on yearly billing. Its "Monthly" option actually bills every 4 weeks, which adds a thirteenth charge to your year, and its headline money-back guarantee sits beside terms that call every purchase non-refundable. Here is the live price ladder and what you are agreeing to.
Written by Undetected.ai, a competing humanizer · every price quoted from the vendor's own page
The short answer
Grubby AI sells Essential, Pro, Unlimited and Enterprise at $8.99, $9.99, $12.99 and $39.99 a month when you pay for a year up front. Paying as you go costs $19.99, $24.99, $29.99 or $200, charged every 4 weeks, so a year on Essential is 13 charges and $259.87. Essential caps each paste at 500 words and carries 10,000 words; Unlimited has a 30,000-word daily fair-use limit. The site advertises a Turnitin money-back guarantee, while section 8.5 of its terms says purchases are non-refundable apart from price-change cases. Grubby Unlimited on yearly billing is excellent value for heavy users. For a monthly buyer who wants to paste a whole essay at once, it is an expensive way in.
Prices were read on grubby.ai on October 6, 2026 in US dollars, from the rendered Annual tab, the rendered Monthly tab and the plan data behind the page, which agree. Refund, cancellation and company details come from grubby.ai/terms and grubby.ai/guarantee. Price history comes from archived copies of the pricing page.
The ladder
Grubby AI pricing: four plans, two billing cycles
What each plan carries, what the 4-week option costs over a year, and the yearly price. Read October 6, 2026.
| Plan | Humanizer words | Max per input | Every 4 weeks | 4-week plan over a year | Yearly billing | Real saving |
|---|---|---|---|---|---|---|
| Essential | 10,000 words | 500 words | $19.99 | $259.87 | $8.99/mo ($107.88) | 58% |
| Pro | 30,000 words | 1,500 words | $24.99 | $324.87 | $9.99/mo ($119.88) | 63% |
| Unlimited | Unlimited, 30,000 words a day fair use | 2,500 words | $29.99 | $389.87 | $12.99/mo ($155.88) | 60% |
| Enterprise | Unlimited | 2,500 words | $200 | $2,600 | $39.99/mo ($479.88) | 82% |
13
Charges a year on the "Monthly" option, because it renews every 28 days rather than on the same date each month.
58%
The real yearly saving on Essential. The toggle says "Save up to 80%", which only the $200 Enterprise plan reaches.
500
Words per paste on Essential. A 2,000-word paper takes four separate runs on the entry plan.
Each card also shows a struck-through higher price ($22.99, $27.99, $32.99 and $250 on the 4-week tab). Pro and above add Standard and Enhanced rewriting modes; Essential gets Simple mode only. Every plan includes an AutoTyper allowance, a separate feature that types text into a document for you, from 5,000 words a month on Essential. Grubby says it humanizes English text only.
Read the footnote
The Grubby AI "Monthly" plan is billed every 4 weeks
Click Monthly on the Grubby pricing page and each card shows a price followed by "/ mo". Directly underneath, in smaller type, it says "Billed every 4 weeks". The plan data behind the page confirms it: the pay-as-you-go prices renew on a 28-day interval, not on a calendar month.
That sounds like a rounding detail. It is not. Four weeks is 28 days and a year has 365, so you are charged 13 times a year instead of 12. On Essential at $19.99, that is $259.87 a year rather than the $239.88 the "/ mo" label suggests. Spread over twelve calendar months the effective rate is about $21.66. On Pro it is about $27.07 a month, and on Unlimited about $32.49.
The word allowance follows the same clock. The card headline says "10,000 Humanizer words / month", but the feature list on the Monthly tab says "10,000 Humanizer words / 4 weeks". So the words reset on the billing cycle, and you get thirteen smaller months rather than twelve.
Four-week billing is legal and some subscription businesses use it openly. Our issue is the label. If you budget monthly, read the footnote, not the headline, and expect your charge date to move earlier by two or three days every month. For comparison, every Undetected.ai plan renews on the same date each calendar month, and Starter is $49 a month for 100,000 words. The whole ladder is on our pricing page.
Before you pay
The Grubby AI Turnitin guarantee, and terms that say non-refundable
A banner across the top of the Grubby site promises a Turnitin guarantee, "or your money back". The guarantee page explains it in one sentence:
If our humanized text gets flagged by Turnitin as AI-generated, we'll refund the cost of your subscription.
The terms of service, section 8.5, read differently:
All purchases are non-refundable except as expressly stated in Sections 8.3 and 8.6.
Sections 8.3 and 8.6 deal only with price changes: if Grubby raises your price and you cancel in response, you get a pro-rata refund of the unused period. Nothing else. Section 5 then says any detection guarantee "is governed by its own separate terms". We looked for those terms and could not find them. The page linked as Refund Policy loads the site footer and nothing else, and the guarantee page itself sets no deadline, no proof requirement and no claim process beyond "reach out to our team".
There is also a practical problem. Most students cannot run Turnitin themselves. The AI report usually lives in the instructor's account, and many schools do not show it to students at all. A refund that depends on proving a Turnitin flag depends on evidence you may never be given. The cancel screen inside the app adds a line of its own: "No refunds will be issued for the current billing period."
If you buy and want to claim the guarantee, write to help@grubby.ai, quote the guarantee page word for word, attach whatever report you have, and keep a dated screenshot of the page from the day you paid. A written promise made at the point of sale is your strongest card. If it is refused and you relied on it, a dispute with your card issuer is the fallback. Our full walkthrough is in the Grubby AI refund and cancellation guide.
To be fair about our own side: our terms say payments are non-refundable except where the law requires otherwise, and we do not sell any detector guarantee at all, because no humanizer can see a detector's verdict before your reader runs it. What we offer instead is a one-time trial of three runs of up to 300 words each, so you can judge the rewrite before you spend anything.
Why reviews disagree
Grubby AI used to cost $6.99 a month
Many Grubby AI reviews still quote Essential at $6.99 a month. That was true. An archived copy of the pricing page from April 2025 shows Essential at $6.99 billed monthly with 7,500 words, and $47.88 for a full year. By March 2026 the pay-as-you-go option had moved to 4-week billing at $14.99, with the yearly plan at $83.88. Today it is $19.99 every 4 weeks, or $107.88 a year, and the allowance has grown to 10,000 words.
So the yearly Essential price has more than doubled in about 17 months, and the monthly price has nearly tripled while also switching to a shorter billing cycle. The allowance grew by a third over the same stretch. None of that is unusual in a young category where the underlying AI models cost real money, and Grubby's terms reserve the right to raise prices with 30 days' notice. It matters because the number in a review is probably not the number at checkout.
The paid field
Grubby AI against the humanizers we have priced
Entry price on yearly billing, the pay-as-you-go rate, and what the entry allowance covers. Each row carries the date we read it.
| Tool | Entry price, yearly | Entry price, pay as you go | Entry allowance | Read |
|---|---|---|---|---|
| Grubby AI | $8.99/mo billed yearly ($107.88) | $19.99 every 4 weeks | 10,000 words, 500 words per input | Sep 26, 2026 |
| Undetected.ai | $24/mo billed yearly | $49 a calendar month | 100,000 words across 300 runs, 1,500 words a run | Sep 26, 2026 |
| Undetectable AI | $5/mo billed yearly | $9.99 | 10,000 words a month | Sep 24, 2026 |
| BypassGPT | $8/mo billed yearly | $12 | 5,000 words a month, 500 words per input | Sep 21, 2026 |
| Netus AI | $8.08/mo billed yearly | $14 | 15,000 words, shared with other tools | Sep 22, 2026 |
| Conch AI | $12/mo billed yearly ($144) | $30 | "Unlimited", capped at 1 million tokens a month | Sep 24, 2026 |
Grubby's entry plan is mid-priced on yearly billing and the most expensive pay-as-you-go entry in this table once the thirteenth charge is counted. Its higher tiers are a different story, which the verdict below covers.
Who you are buying from
Study Solutions A16 LLC
The Grubby footer names Study Solutions A16 LLC as the holder of the GRUBBY.AI registered service mark. Support runs through help@grubby.ai and hello@grubby.ai. The cancellation section of the terms is written with US buyers in mind: it cites the California Automatic Renewal Law and New York's automatic renewal rules, and it commits to cancellation from the account dashboard, which is the right way to do it.
The price-change section is also more generous than most. Grubby promises 30 days' written notice of any increase, the reason for it, and a pro-rata refund if you cancel because of it. If you are already on a plan, that protects you from surprise increases better than several rivals do.
One thing to keep in mind if you search for help. The top Google result titled "Grubby Help Center" for cancelling a subscription belongs to a UK meal-kit company with a similar name, and its steps are about food deliveries. Use the Grubby AI account dashboard, not that article.
Grubby markets itself heavily to students and names Turnitin in its guarantee. If you are a student, read your school's policy on AI assistance before relying on any humanizer, ours included. A rewrite can make a draft read more naturally; it does not change what your course allows.
Honest verdict
Where Grubby AI is the better buy, and where we are
Start with where Grubby wins, because it wins clearly on yearly billing at the top of its ladder. Unlimited costs $12.99 a month paid yearly, with a fair-use ceiling of 30,000 words a day and 2,500 words per paste. Our Scale plan is $99 a month billed yearly for 1,000,000 words and takes 1,500 words per run. If you humanize hundreds of thousands of words a month and are happy to commit for a year, Grubby Unlimited is the cheaper tool and we would rather say so. Grubby Pro on yearly billing, $9.99 a month for 30,000 words, is also cheaper to start than our Starter at $24, although our Starter carries 100,000 words and works out lower per word ($0.24 per 1,000 against about $0.33).
Where we would argue for ourselves is the monthly buyer and the entry plan. Our Starter is $49 a calendar month for 100,000 words and 1,500 words per run, against Grubby Essential at $19.99 every 4 weeks for 10,000 words and 500 per paste. Our Pro is $99 a month for 300,000 words against Grubby Pro at $24.99 every 4 weeks for 30,000. We cost more to start, but on month-to-month terms we give you ten times the words, which puts our cost per 1,000 words well below Grubby's, charged twelve times a year rather than thirteen.
We also show our own AI-pattern score before and after each rewrite, with the reasons behind the number, so you can see what changed rather than trust a badge. Neither we nor Grubby can show you what Turnitin, GPTZero or any other detector will say about your text before your reader runs it, and we do not sell a guarantee that implies otherwise.
Short version: buy Grubby Unlimited or Pro on a yearly plan if you write a lot and the English-only limit is fine. Buy a calendar-month humanizer if you want to pay as you go, paste long drafts in one piece and skip the thirteenth charge. The wider field is compared in our best AI humanizer roundup, and every paid tool is ranked by cost per thousand words in the cheapest AI humanizer.
Questions buyers ask
Grubby AI pricing, billing and refunds
How much is Grubby AI?
Grubby AI costs $8.99, $9.99, $12.99 or $39.99 a month on yearly billing ($107.88, $119.88, $155.88 or $479.88 up front) for Essential, Pro, Unlimited and Enterprise. The "Monthly" option is $19.99, $24.99, $29.99 or $200, billed every 4 weeks. Prices read in US dollars on grubby.ai on October 6, 2026.
Is Grubby AI billed monthly or every 4 weeks?
Every 4 weeks. The toggle says Monthly and the card says "/ mo", but the footnote under each price reads "Billed every 4 weeks" and the plan data uses a 28-day interval. That is 13 charges a year, so the Essential plan at $19.99 costs $259.87 over twelve months, not $239.88.
Is Grubby AI free?
Only for a taste. Grubby gives every account 300 words a month without paying, which is about one short page. Paid plans start at $8.99 a month billed yearly. Essential also limits each paste to 500 words, so a full essay has to be split into several runs even after you pay.
Does Grubby AI give refunds?
Rarely. Section 8.5 of the terms says "All purchases are non-refundable except as expressly stated in Sections 8.3 and 8.6", which cover price changes. Separately, Grubby advertises a Turnitin guarantee that refunds your subscription if its text is flagged. The terms say that offer has its own separate terms, which we could not find published.
How do I cancel my Grubby AI subscription?
Log in at grubby.ai and cancel from the subscription option in your account settings, which section 9.4 of the terms names as the route. The flow asks for a reason and may offer a discount, a free billing cycle or a pause before it confirms. You keep access until the paid period ends, and no refund is issued for that period.
Why is Grubby AI more expensive than reviews say?
Because the prices moved. An archived copy of the pricing page from April 2025 shows Essential at $6.99 a month and $47.88 a year, with 7,500 words. By March 2026 it was $14.99 every 4 weeks. It is now $19.99 every 4 weeks or $107.88 a year, with 10,000 words. Many reviews still quote $6.99.
Is Grubby AI legit?
It is a real, paid product run by Study Solutions A16 LLC, which holds the GRUBBY.AI service mark. The things to weigh are the 4-week billing sold under a monthly label, a refund promise the terms mostly rule out, the 500-word input limit on the entry plan, and English-only support.
What is a good Grubby AI alternative?
If you need volume and want to pay by the calendar month, Undetected.ai Starter is $49 a month for 100,000 words, with 1,500 words per run on every plan. It costs more to start than Grubby Essential, but carries ten times the words, so it works out cheaper per 1,000 words. If you write very high volume and will commit for a year, Grubby Unlimited at $12.99 a month is hard to beat on price.
Keep reading
The rest of the paid field, read the same way
Grubby AI refund and cancellation
How to cancel, the retention offers you will see, and how to claim the Turnitin guarantee in writing.
Grubby AI alternative
A calendar-month plan against Grubby's 4-week billing, side by side, with where Grubby still wins.
BypassGPT review
The same 500-word paste cap on the entry plan, one of the best unlimited offers, and a refund that ends at 1,000 words.
Conch AI review
A student suite whose price tripled since June, and a refund promise its own terms contradict.
Undetectable AI pricing
The cheapest entry price in the category, tier by tier, and what the annual figure commits you to up front.
Essay humanizer
Humanize a full essay in one run of up to 1,500 words, with the reasons behind every change shown.
AI humanizer for students
What to check before you use any humanizer on coursework, and how our plans compare on a student budget.
Try a humanizer billed by the calendar month
Paste a real draft of up to 1,500 words and run it once. Our AI-pattern score reports what changed and why, before and after, and the plan you pick renews on the same date every month.