QuillBot vs Undetectable AI (2026): which should you pick?
As of Nov 13, 2026, QuillBot grades higher than Undetectable AI: 2.8 against 2.2 out of 4.0.
Checked Oct 5, 2026 and Nov 13, 2026 · graded Oct 10, 2026 and Nov 13, 2026 by ToolGPA
QuillBot grades higher on the free plan, features, ease of use and platforms. Undetectable AI grades higher on value for money.
Price, platforms and features side by side. The table says where each price was read and when.
QuillBot
AI paraphraser with grammar, summarizing and AI-detection tools
Undetectable AI
AI humanizer and AI detector sold by monthly word allowance
Which one is for you
Pick QuillBot if
- Fits if you often need to reword or shorten something that's already written
- Works for people who want paraphrasing, grammar and citations under one login
Look elsewhere if
- Tight if you're staying free, since it rewords at most 125 words at a time in 2 modes and summarizes up to 1,200
- Pricey if you pay month by month, which the iOS app lists at $19.99
- Skip it if you need lots of plagiarism checking, as that's Premium only and stops at 25,000 words a month
- Watch out: the site says free limits may vary across platforms, and Premium summaries stop at 6,000 words
- Watch out: the Team plan is billed every 12 months and starts at 2 seats
Pick Undetectable AI if
- Fits if you need to rewrite short pieces and have a small word budget
- Works for people who also want a detector alongside
Look elsewhere if
- Tight if you try it first: the trial is 250 words
- Pricey if you write a lot, because plans are measured in words a month
- Watch out: $5 is the yearly rate; month-to-month the first plan is $9.99
- Watch out: non-expiring credits and white labelling are on the custom business plan only
How we grade them
| 2.8GPAQuillBotGood | 2.2GPAUndetectable AIFair | |
|---|---|---|
| Value for money | CPremium is $8.33 a month billed annually, which is exactly the middle for writing tools, and one account covers every tool on up to 10 devices. Monthly billing is another story: the iOS app lists it at $19.99. | B$5 a month billed annually for 10,000 words, inside the category's cheapest quarter at $5.75. Month-to-month it's $9.99, around the middle. |
| Free plan and trial | CFree for good, but in small bites, and the caps are ones you'll hit: paraphrasing 125 words at a time in 2 modes, basic grammar fixes, summaries of up to 1,200 words, and limited goes on the Humanizer, AI Detector and AI chat. | DA free trial capped at 250 words, and the listing doesn't say whether a card is needed. |
| Features | BIt covers the whole job of a rewriting and checking kit: a paraphraser with 9 modes plus custom ones of your own in 23 languages, a grammar checker, a summarizer, a translator for more than 40 languages, an AI detector, a humanizer, plagiarism checks and a citation generator. | CHumanizer, detector, writing tools and a refund if flagged. It covers the job, with a word budget attached. |
| Ease of use | BNo store rating on record, so we go on the listing: paste text, pick a mode, read the new version, with nothing to set up, and the extensions and keyboards put it where you already type. The free plan lets you try that before paying. | CNo store rating on record. Pasting text in is quick, but results need checking. |
| Platforms and integrations | AWeb, Mac and Windows apps, iPhone and Android apps and keyboards, plus Chrome, Edge and Safari extensions and a Word add-in. Every device type covered and places to plug into, which is rare in this category. Premium runs on up to 10 devices at a time. | BWeb and a Chrome extension, with an API. |
| Best for | rewording text you've already written | rewriting text so it passes AI detectors |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: QuillBot and Undetectable AI. How we grade
Price against what you get
QuillBot starts at $8.33 a month and scores 3.3 out of 4 on features, ease of use and platforms. Undetectable AI starts at $5 a month and scores 2.3.
QuillBot scores higher, and starts $3.33 a month higher: the question is whether the extra is worth that to you. Of the other writing tools on the chart, none scores higher than QuillBot for less, and 13 score higher than Undetectable AI for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- QuillBot also covers chat assistant, citations and grammar & style.
- Undetectable AI also covers documents.
At a glance
| QuillBot | Undetectable AI | |
|---|---|---|
| Pricing | Free plan | Free trial |
| Starts at | $8.33 per month, billed annually (Premium) | $5 per month for 10K words, billed annually ($9.99 billed monthly) |
| Free plan | Paraphrase up to 125 words in 2 modes, basic grammar fixes, summaries of up to 1,200 words, and limited use of the Humanizer, AI Detector and AI chat. Limits may vary across platforms. | None |
| Free trial | None listed | Free trial limited to 250 words; more use needs a paid plan |
| Web | ||
| macOS | ||
| Windows | ||
| iOS | ||
| Android | ||
| Browser extension | ||
| Made by | Learneo, Inc. | Undetectable Inc. |
| Price read from | web.archive.org (not the vendor's own page) | undetectable.ai |
| Checked | Oct 5, 2026 | Nov 13, 2026 |
Worth knowing
QuillBot
- The free plan paraphrases at most 125 words at a time and offers only the Standard and Fluency modes.
- Free summaries are capped at 1,200 words; Premium raises the cap to 6,000.
- Plagiarism checking is a Premium feature and is limited to 25,000 words a month.
- The pricing page leads with annual billing at $8.33 a month; the iOS app lists monthly billing at $19.99.
Undetectable AI
- The free trial is capped at 250 words.
- Plans are measured in words per month, so heavy users move to the larger tiers quickly.
- The $5 figure is the yearly-billing rate with a crossed-out $9.99; month-to-month the first plan is $9.99.
- Non-expiring credits and white labeling are offered only on the custom business plan.
Key features
QuillBot
- Paraphraser
- Rewords text in built-in modes: Standard and Fluency on the free plan, 9 modes plus unlimited custom modes on Premium. It paraphrases in 23 languages.
- Grammar Checker
- Fixes basic grammar errors on the free plan and adds advanced writing suggestions and tone insights on Premium. Grammar correction covers 6 languages.
- AI Detector and Humanizer
- The AI Detector flags AI-generated content, and the Humanizer rewrites text so it reads more naturally. Free use of both is limited; Premium gives full access.
- Summarizer and Translator
- Summarizes up to 1,200 words on the free plan and 6,000 on Premium, which adds custom summaries. The Translator covers more than 40 languages.
- Plagiarism and citation tools
- Premium scans up to 25,000 words a month for accidental plagiarism, and the Citation Generator formats references in APA, MLA and Chicago styles.
- Extensions and apps
- Chrome, Edge and Safari extensions, a Word add-in, macOS and Windows apps, and iOS and Android keyboards and apps. Premium runs on up to 10 devices at a time.
Undetectable AI
- AI humanizer
- Rewrites AI-generated text with the aim of passing AI detectors, with writing-level matching.
- AI detector
- Paid plans list unlimited AI detecting. Separate detectors exist for images, voice, video, deepfakes and fake PDFs, receipts and IDs.
- Writing tools
- The site also lists an essay writer, stealth writer, paraphrasing tool, SEO content writer, plagiarism checker and a human auto-typer.
- Refund if flagged
- The pricing page says the cost of a humanization is refunded if the output is flagged as not human; details are on the Help pages.
- API and Chrome extension
- Plans are marked API compatible, and the site lists a Chrome extension.
Plans
QuillBot
Free$0
Paraphrase up to 125 words in 2 modes, fix basic grammar errors, summarize up to 1,200 words, and use the Humanizer and AI Detector with limits.
Premium$8.33
per month, billed annually
Full paraphrasing in 9 modes plus custom modes, advanced grammar suggestions, 6,000-word summaries, the full AI Detector and plagiarism checks on 25,000 words a month.
Team Plan$7.50
per seat / month, billed every 12 months ($89.95), for 2-10 seats
All Premium features plus writer-management dashboards and centralized billing. $6.66 a seat for 11-50 seats and $5.83 for 51 or more.
Undetectable AI
10K words$5
per month for 10,000 words, billed annually ($9.99 billed monthly)
10,000 words a month, charged $60 a year. The page crosses out $9.99 and marks yearly billing as 50% off.
20K words$9.50
per month for 20,000 words, billed annually ($19 billed monthly)
20,000 words a month, charged $114 a year.
35K words$15.75
per month for 35,000 words, billed annually ($31 billed monthly)
35,000 words a month, charged $189 a year.
50K words$21.25
per month for 50,000 words, billed annually ($42.50 billed monthly)
50,000 words a month. Larger allowances up to 380,000 words are listed, with custom pricing on request.
Ways to pay less
QuillBot
- Annual discount
Annual billing marked as 58% off
The pricing page labels annual billing 58% off the monthly rate, which brings Premium to $8.33 a month. In the iOS app the plans are $99.99 a year or $19.99 a month.
- Other savings
Team seats cost 10% to 30% less
Team plans are $7.50 a seat per month for 2-10 seats, $6.66 for 11-50 and $5.83 for 51 or more, billed every 12 months and labeled as 10%, 20% and 30% savings.
Undetectable AI
- Annual discount
Yearly billing at half the monthly price
The pricing page marks yearly billing as 50% off the monthly rate, for example $60 a year for 10,000 words a month.
Common questions
Which is cheaper, QuillBot or Undetectable AI?
As of Nov 13, 2026, Undetectable AI is cheaper to start with: $5 a month, against $8.33 a month for QuillBot. QuillBot starts at $8.33 per month, billed annually (Premium), and Undetectable AI starts at $5 per month for 10K words, billed annually ($9.99 billed monthly).
Which has a free plan, QuillBot or Undetectable AI?
As of Nov 13, 2026, only QuillBot has a free plan. Undetectable AI does not, though it has a free trial.
Which platforms do QuillBot and Undetectable AI run on?
As of Nov 13, 2026, only QuillBot lists macOS, Windows, iOS and Android apps. Both list a web app and a browser extension. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.