AI detectors you can use free October 2026
Word limits, sign-up and warnings, read on the pages of 12 AI detectors. Most check text free, and their own makers say a score can be wrong.
Checked by hand on 16 October 2026, on each company’s own pages.All 48 quotes re-checked 22h ago and still there.
The short answer
If you read nothing else, read this.
- Most text in one free check: Copyleaks takes 25,000 characters in one scan, with no login. ZeroGPT takes 15,000, GPTZero and Grammarly 10,000. Others count words: Originality 2,000, QuillBot and Scribbr 1,200, Trinka 500. Characters count every letter and space, so they add up faster than words.
- No account needed: Copyleaks, Originality (3 scans a day) and Scribbr say you can check without one, and GPTZero up to 10,000 characters. Pangram and Winston need an account.
- Free every day or month: GPTZero gives 10,000 words a month, QuillBot 6 scans a day, Trinka 10 sessions of 500 words a day, and Pangram 2,000 words a day with an account. ZeroGPT's plan table lists 1,250,000 words a month without explaining it. Winston's "Free" plan is only a 14-day trial.
- Turnitin is not for individuals: it sells only to schools, universities and organizations, and its AI check comes only with their accounts. Students should ask their school if it has Turnitin.
- They warn you themselves: GPTZero, Grammarly, QuillBot, Originality, Scribbr, Sapling and Trinka say on the checker's own page that a score can be wrong or is not enough alone. Turnitin and Winston say it in their help pages, Copyleaks and Pangram only in their terms. ZeroGPT's FAQ only explains why human writing gets flagged.
- Accuracy numbers are their own claims: we could not check them. Turnitin itself says it "might flag a human-written document as AI-written for one out of every 100 fully-human written documents."
I read the pages of 12 AI detectors. Not one says its score is proof.
Quick picks
Most text in one free check
Copyleaks
25,000 characters
In one scan, with no login. It does not say how many free scans you get.
Free plan built for education
GPTZero
10,000 words a month
Up to 10,000 characters a scan, with no account needed for that.
Daily scans, no account
Originality.ai
3 scans a day
Up to 2,000 words each. It checks for AI only, not for copying.
Turnitin without a school
Turnitin
Not for individuals
Sold only to schools and organizations. Students: ask your school if it has it.
Compare them all
All 12, side by side. Tap a name for the sentences behind it.
Most text in one free check
- Copyleaks25,000 charactersFree allowance Not stated · Sign-up Not needed · Warns of errors Only in its terms · Paid from $13.99 a month, billed yearlyTry free
ZeroGPT15,000 charactersFree allowance 1,250,000 words a month · Sign-up Not stated · Warns of errors Mildly, in its FAQ · Paid from $107.88 a year, $14.99 monthlyTry free- GPTZero10,000 charactersFree allowance 10,000 words a month · Sign-up Not needed · Warns of errors Yes, on the tool page · Paid from $12.99 a month, billed yearlyTry free
Grammarly10,000 charactersFree allowance Not stated · Sign-up Not stated · Warns of errors Yes, on the tool page · Paid from $12 (Pro), billing not statedTry free
Smaller free checks
- Originality.ai2,000 wordsFree allowance 3 scans a day · Sign-up Not needed · Warns of errors Yes, on the tool page · Paid from $12.95 a month, billed yearlyTry free
- QuillBot1,200 wordsFree allowance 6 scans a day · Sign-up Not stated · Warns of errors Yes, on the tool page · Paid from $8.33 a month, billed yearlyTry free
- Scribbr1,200 wordsFree allowance Unlimited, Scribbr says · Sign-up Not needed · Warns of errors Yes, on the tool page · Paid from Premium, no price foundTry free
Trinka500 wordsFree allowance 10 sessions a day · Sign-up Not stated · Warns of errors Yes, on the tool page · Paid from $125 a year (Premium Plus)Try free
PangramNot statedFree allowance 2,000 words a day · Sign-up Needed, no card · Warns of errors Only in its terms · Paid from $20 a monthTry free
Sapling2,000 charactersFree allowance Not stated · Sign-up Not stated · Warns of errors Yes, on the tool page · Paid from $12 a month yearly, $25 monthlyTry free
A trial, or schools only
Winston AINot statedFree allowance 2,000 credits for 14 days · Sign-up Needed, no card · Warns of errors Yes, in its help pages · Paid from $10 a month yearly, $18 monthlyTry free- TurnitinNot for individualsFree allowance None · Sign-up School account only · Warns of errors Yes, in its guides · Paid from Schools and organizationsOpen
– means their own pages do not say.
Most text in one free check
Each takes 10,000 characters or more at a time. Read on each company's own pages on 5 October 2026.
- Per check
- 25,000 characters
- Free allowance
- Not stated
- Sign-up
- Not needed
- Warns of errors
- Only in its terms
- Paid from
- $13.99 a month, billed yearly
- Languages
- Over 30
Copyleaks does not say how many free scans you get, or if they come back. A free account adds "more monthly credits", with no number, and its price page shows no free plan. On its detector page it claims "over 99% accuracy and an industry-low .03% false positive rate"; its terms say the results must not be the only reason to act against someone. Month to month, the cheapest plan is $16.99.
In their own words(4, checked 5 Oct)
“free for up to 25,000 characters per scan”
“You can scan up to 25,000 characters without logging in, a higher limit than most major AI detection tools.”
“the AI Features are not intended to be, and shall not be, used as the sole basis for adverse decisions about individuals”
“$16.99/month or $13.99/month when billed annually”
- Per check
- 15,000 characters
- Free allowance
- 1,250,000 words a month
- Sign-up
- Not stated
- Warns of errors
- Mildly, in its FAQ
- Paid from
- $107.88 a year, $14.99 monthly
The monthly figure is in the Free column of its plan table, which does not explain it. No page says if checks work without an account. Its FAQ explains why human writing can be flagged, but does not say a score should not be the only proof. Free use shows ads, and refunds are only within 6 hours of buying a monthly plan, or 10 hours for a yearly one.
In their own words(4, checked 5 Oct)
“$0 forever”
“Maximum number of characters per AI detection 15,000”
“Words Allowance 1,250,000 /month”
“Highly polished, formulaic, or low-entropy writing can resemble AI.”
- Per check
- 10,000 characters
- Free allowance
- 10,000 words a month
- Sign-up
- Not needed
- Warns of errors
- Yes, on the tool page
- Paid from
- $12.99 a month, billed yearly
- File upload
- Yes
Now part of Superhuman, the company behind Grammarly. You need a free account only for scans over 10,000 characters; GPTZero does not say how the monthly words count without one. Its FAQ says a free account reads up to 150,000 characters at once, though the free plan gives 10,000 words a month. Premium gives 300,000 words a month and lists detection in more languages among its extras.
In their own words(4, checked 5 Oct)
“GPTZero offers a free plan built for education, allowing you to scan up to 10,000 words a month and use our Chrome Extension.”
“To get the power of our AI detector for texts up to 150,000 characters, or a batch of up to 250 files, sign up for a free account.”
“For scans over 10,000 characters, create a free account first.”
“No AI detector is 100% accurate, and AI itself is changing constantly. Results should not be used to punish or as the final verdict.”
- Per check
- 10,000 characters
- Free allowance
- Not stated
- Sign-up
- Not stated
- Warns of errors
- Yes, on the tool page
- Paid from
- $12 (Pro), billing not stated
- Languages
- English only
Part of Superhuman, which also owns GPTZero. The 10,000-character limit and the English-only line come from Grammarly's own blog, not from the tool itself. Its page shows how to scan, with no step for an account, but does not say if you need one. Checking for AI inside Grammarly's apps, Google Docs or Word is a paid feature. The Pro plan offers a free trial but does not say how long.
In their own words(4, checked 16 Oct)
“Using Grammarly’s free AI detector is simple: Paste your text or upload a document into the tool at the top of this page.”
“Grammarly’s free, in-browser AI detector can analyze up to 10,000 characters at once to estimate how likely they are AI-generated.”
“Detection is currently available for English content only.”
“No AI detector is 100% accurate. This means you should never rely on the results of an AI detector alone to determine whether AI was used to generate content.”
Smaller free checks
Up to 2,000 words at a time, and most limit how many checks you get a day.
- Per check
- 2,000 words
- Free allowance
- 3 scans a day
- Sign-up
- Not needed
- Warns of errors
- Yes, on the tool page
- Paid from
- $12.95 a month, billed yearly
- File upload
- Yes: docx, doc, pdf
The free checker is on the home page. It checks for AI only, not copying, and a text needs at least 100 words. Originality says it has no free trial. On its blog it claims its current model is "99%+ Accurate at 15% AI Allowed", but does not say which model the free checker uses. Month to month, Pro is $14.95.
In their own words(4, checked 5 Oct)
“Check up to 2,000 words with the free AI checker, and run up to 3 free AI scans daily.”
“No, you can run up to 3 free AI scans daily without an account.”
“An AI score shouldn’t be used alone for academic integrity discipline.”
“You will be billed yearly for an amount of: $155.4 ($12.95 x 12 months) instead of $179.4 ($14.95 x 12 months).”
QuillBot
- Per check
- 1,200 words
- Free allowance
- 6 scans a day
- Sign-up
- Not stated
- Warns of errors
- Yes, on the tool page
- Paid from
- $8.33 a month, billed yearly
- File upload
- 1 file at a time
QuillBot's pages disagree: the detector page says 6 scans a day, a help page comparing plans says 10, and another says detection works the same on Free and Premium. We follow the detector page. A scan needs at least 80 words. Premium has no word limit.
In their own words(4, checked 5 Oct)
“Quillbot’s AI Detector is a free tool available to all users.”
“Up to 1,200 words per scan”
“Up to 6 scans per day”
“Scores are signals, not verdicts. Never make an academic or employment decision on a detector score alone”
Scribbr
- Per check
- 1,200 words
- Free allowance
- Unlimited, Scribbr says
- Sign-up
- Not needed
- Warns of errors
- Yes, on the tool page
- Paid from
- Premium, no price found
- Languages
- English, Spanish, German, French
The checker on Scribbr's page is QuillBot's: the page code loads it from QuillBot, and the page suggests "the AI Detector from QuillBot". QuillBot's own page says 6 scans a day, which does not match Scribbr's "unlimited". Scribbr's FAQ says the free version spots GPT2 to GPT3.5 text "with average accuracy", which looks out of date. Free use shows ads.
In their own words(4, checked 5 Oct)
“Perform an unlimited number of AI checks for free, with a limit of up to 1,200 words per submission, ensuring all of your work is authentic.”
“Start detecting AI-generated content instantly with our free AI Detector, without having to create an account.”
“However, no AI model on the market can guarantee 100% accuracy, including ours.”
“our AI Detector can currently analyze text in English, Spanish, German, and French”
- Per check
- 500 words
- Free allowance
- 10 sessions a day
- Sign-up
- Not stated
- Warns of errors
- Yes, on the tool page
- Paid from
- $125 a year (Premium Plus)
Trinka is a grammar and writing tool for academic work. Longer texts and Word or PDF uploads come after you sign up free, but Trinka does not say if they are part of the free tier. Premium Plus, the cheapest plan with the detector, includes 120 pages of AI checks, its detector page says.
In their own words(4, checked 5 Oct)
“Trinka's AI Detector is available for free with certain limitations.”
“Users can enjoy up to 10 sessions per day, with each session allowing analysis of up to 500 words.”
“However, this evaluation might not always accurately distinguish between human and AI-created content, so it should not be the sole factor in determining the nature of the content.”
“$ 125 /year”
- Per check
- Not stated
- Free allowance
- 2,000 words a day
- Sign-up
- Needed, no card
- Warns of errors
- Only in its terms
- Paid from
- $20 a month
- Trial
- 7 days, then $20 a month
Pangram counts free use two ways: 20 credits a day, enough for 2,000 words, in its help center, and "twenty free checks a day" on its home page. Its help center says the free plan reads uploaded files, even scanned ones, but its price page lists file upload as a paid extra. Its warning that a result is "one signal among many" is in its terms of service, in the part about its text-message service.
In their own words(4, checked 16 Oct)
“The Free plan lets you use Pangram with no payment method required.”
“20 credits per day - enough to scan up to 2,000 words daily.”
“We offer twenty free checks a day after signing up for our free plan, including AI assistance detection.”
“You should treat any prediction as one signal among many; Pangram does not warrant or guarantee the accuracy of any individual prediction.”
- Per check
- 2,000 characters
- Free allowance
- Not stated
- Sign-up
- Not stated
- Warns of errors
- Yes, on the tool page
- Paid from
- $12 a month yearly, $25 monthly
- Trial
- 1 month of Pro, no card
The free check reads only the first 2,000 characters of your text and skips the rest. Pro reads up to 100,000 characters a check, and you can try it free for a month without a card. Sapling gives no single accuracy figure, and does not say which languages it reads.
In their own words(4, checked 5 Oct)
“This check covers the first 2,000 characters. Pro supports up to 100,000 characters per check.”
“Haven't yet registered? Just sign up (no credit card required) to start a free 1-month trial of Sapling Pro.”
“No current AI content detector (including Sapling's) should be used as a standalone check to determine whether text is AI-generated or written by a human. False positives and false negatives will occur.”
“Annual · $12/mo”
A trial, or schools only
Winston gives a 14-day trial, not a lasting free plan. Turnitin is sold only to schools and organizations.
- Per check
- Not stated
- Free allowance
- 2,000 credits for 14 days
- Sign-up
- Needed, no card
- Warns of errors
- Yes, in its help pages
- Paid from
- $10 a month yearly, $18 monthly
Winston's Free plan is a 14-day trial, not a lasting free plan. Each scan uses credits depending on how much text and which tools you turn on, so we do not turn credits into words. A scan needs at least 500 characters, and yearly plans cannot be cancelled during the year. Its pages disagree on the in-house test behind its "99.87% overall accuracy" claim: 10,000 samples on its home page, 12,000 documents on its price page.
In their own words(4, checked 5 Oct)
“The Free plan provides 2,000 credits for 14 days so you can try Winston AI before choosing a paid plan.”
“Create your account for free to begin checking for AI content.”
“No credit card required.”
“A result should be treated as evidence to review, not automatic proof of misconduct.”
Turnitin
- Per check
- Not for individuals
- Free allowance
- None
- Sign-up
- School account only
- Warns of errors
- Yes, in its guides
- Paid from
- Schools and organizations
Turnitin sells only to schools, universities and organizations, and its AI check works only through their accounts. For single people it points to iThenticate, its tool for checking copied text, and those credit packs do not include the AI check. Its AI check reads long-form English, Spanish, Japanese and Modern Arabic. AI scores under 20% get an asterisk, because Turnitin's testing found more false positives there.
In their own words(4, checked 5 Oct)
“Turnitin does not sell individual licenses or single-use subscriptions.”
“No, AI Writing Detection is not available for individual user packages, including individual credits or 3-credit packages”
“Our AI writing detection model may not always be accurate (it may misidentify human-written, AI-generated, and AI-paraphrased text), so it should not be used as the sole basis for adverse actions against a student.”
“In other words, we might flag a human-written document as AI-written for one out of every 100 fully-human written documents.”
Questions
What is the best free AI detector for essays?
For a long essay, pick one with a big limit per check. Copyleaks takes 25,000 characters with no login, ZeroGPT 15,000, GPTZero and Grammarly 10,000. GPTZero also gives 10,000 words a month, and Originality.ai 3 scans a day of up to 2,000 words, with no account. None of them says its score is proof.
Can I use Turnitin's AI detector for free?
No. Turnitin does not sell individual licenses, and its AI writing check comes only with a school, university or organization account. For single people it points to iThenticate credit packs, and those do not include the AI check. If you are a student, ask your school if it has Turnitin.
Is GPTZero free?
Yes. The free plan gives 10,000 words a month. You can check up to 10,000 characters at a time with no account, and longer texts with a free account. Premium is $12.99 a month, billed yearly, for 300,000 words a month. GPTZero is now part of Superhuman, the company behind Grammarly.
Which free AI detector is best for teachers?
First ask if your school has Turnitin: its AI check comes only with school accounts. For free, GPTZero says its free plan is built for education, with 10,000 words a month. Before you act on any score, read the warnings. QuillBot says never to make an academic decision on a score alone, and Turnitin marks AI scores under 20% with an asterisk, because its testing found more false positives there.
Can AI detectors be wrong?
Yes, and their makers say so. Grammarly: "No AI detector is 100% accurate." Sapling: "False positives and false negatives will occur." Turnitin says it "might flag a human-written document as AI-written for one out of every 100 fully-human written documents." High figures on their pages, like GPTZero's "99% accuracy rate", are their own claims.
Is there a free AI detector with no sign-up?
Yes. Copyleaks checks up to 25,000 characters without logging in. Originality.ai gives 3 scans a day without an account, and Scribbr says you need none. GPTZero asks for a free account only for scans over 10,000 characters. Pangram and Winston AI need an account, and Grammarly, ZeroGPT, QuillBot, Sapling and Trinka do not say.
How we checked
Every fact here comes from the company’s own page, with the sentence it is in. The facts checked for this guide show the day we read them. The tables come from our catalogue, which re-reads each price page on its own. When a page does not say something, we write that, and we never guess. How we check