Is there a free AI detector with no limit? The field data
Two of the 22 AI detectors in the index state a free tier with no limit on the number of checks: Scribbr, "Unlimited free AI checks, no sign-up required" (scribbr.com, read 8 November 2026), and Phrasly, "no limit to how many times you can use the AI Detector, no character limits, no monthly scan caps" (phrasly.ai, read 8 November 2026). Every other free tier in the index is capped per scan, per day or per month, is a one-time total, or states no quantity, per the free tier field of each card read on 8 or 9 November 2026.
"No limit" can mean three things: no cap on how many checks you run, no cap on how long each text can be, and no cap on how many words you can check in a month. Only Phrasly states all three for its web tool, and Phrasly asks for texts of at least 30 words. The table gives every card's free tier in the vendor's own words, the period the vendor states, and the input limit per check, so the three meanings can be read apart. This page is one of the questions answered from the index; the siblings ask whether a 100% accurate AI detector exists and whether a legit AI detector exists.
| Detector | Free tier, in the vendor's words | Period | Input limit per check, as the vendor states | Source, read 8 November 2026 |
|---|---|---|---|---|
| Scribbr | Unlimited free AI checks, no sign-up required | scribbr.com | ||
| Phrasly | 100% free to use, no limit to how many times you can use the AI Detector, no character limits, no monthly scan caps, no credit card, no signup barriers; text highlighting only for signed-in users | Web tool: at least 30 words, no character limits; Business API: at least 50 words, max 15,000 characters per request | phrasly.ai | |
| ZeroGPT | $0 forever, no credit card: 15,000 characters per AI detection, words allowance 1,250,000 /month, 0 batch files, no PDF reports, no detection history; plagiarism checker 300 words one-time-only | per month | FREE 15,000 characters per detection; guidance of at least 150 to 200 words | zerogpt.com/pricing |
| GPTZero | Free plan covering 10,000 words per month (vendor blog, Oct 25, 2026); 10,000 characters per scan without login | per month | 10,000 characters per scan without an account; up to 150,000 characters or 250 files with a free account | gptzero.me |
| WasItAI | Free: $0/month, 10 images per month, API access, browser extension, confidence score, dashboard and detailed reports, no card required; guest checks run without an account until the guest limit | per month | Images only: max image size 8MB, 10000x10000px; drag and drop, choose a file or enter an image URL | wasitai.com/api, read 9 November 2026 |
| Reality Defender | Free API plan: $0/month, 50 scans per month, up to 3 seats, image analysis only, API keys and an analytics dashboard; audio and video need a paid plan | per month | SDK files: images up to 50MB, audio up to 20MB, video up to 250 MB and 30 minutes, text .txt up to 900KB; the Free plan supports image uploads only | realitydefender.com/api, read 9 November 2026 |
| QuillBot | Up to 1,200 words per scan, up to 6 scans per day, 1 free explainer card; no sign-up for scans under 1,200 words | per day | Minimum 80 words; free up to 1,200 words per scan; Premium no word limit | quillbot.com |
| Pangram | 20 free credits daily (twenty free checks a day after signing up for the free plan, including AI assistance detection) | per day | PDF, DOCX, RTF, up to 100 files at a time; words per check not published | pangram.com |
| Copyleaks | Free for up to 25,000 characters per scan; every new user receives a limited number of free credits (count not published); a free account unlocks more monthly credits | per check | Minimum 255 characters; free scan up to 25,000 characters; 1 credit covers 250 words | copyleaks.com |
| Sapling | Free plan $0 / month: AI detector checks up to 2,000 characters per check, 5 files per detector batch; count of checks per period not capped. Free 1-month trial of Sapling Pro on registration (no credit card). API: new keys get 50,000 characters/day and 250,000 characters/month. | per check | Free check covers the first 2,000 characters; Pro and Enterprise up to 100,000 | sapling.ai/pricing |
| Winston AI | Free: $0 /month, 2,000 credits / 14 day trial (not recurring). API: register for free and receive 2,500 credits. | total | Up to 200,000 characters per scan on paid plans; Free row blank | gowinston.ai/pricing |
| Originality.ai | Free, no subscription required, $0: 10K words (100 credits one time) | total | 100-word minimum; 1 credit = 100 words | originality.ai/pricing |
| Proofademic | Free $0 /month: 3-Day Trial, no credit card, one-time 1,000 words; includes Multilingual AI Detection, Plagiarism Checker, Report Export. API: 2,000 trial credits (1 credit = 1 word). | total | Free: one-time 1,000-word scan; paid 3,500 to 25,000 words per request | proofademic.ai/pricing |
| Walter Writes | Free 300-word trial, no credit card required (homepage); pricing FAQ defers to the Start free trial link for current limits. API: start on the free tier (size not published). | total | 750 to 2,000 words per request on paid plans | walterwrites.ai |
| AIDetectPlus | 1,000 free credits (1,000 words) on account creation, one time, with the full marked-up report; the home page widget scans up to 3,000 characters with no account | one time | Home page widget: a 3,000-character box, free with no account; signed-in detectors take pasted text or .docx, .pdf, .txt and .html at 1 credit = 1 word, no per-document maximum published | aidetectplus.com, read 9 November 2026 |
| Grammarly | Free AI Detector, no sign-up needed; allowance per period not published. On the plans page the Detect AI generated text row is unchecked for Free and checked for Plus and Pro. | grammarly.com/plans | ||
| JustDone | No setup and no account needed for your first scan; quantity per period not published | Up to 15,000 words in one scan; at least 350 characters | justdone.com | |
| Hive | Free AI detector Chrome extension (no fees or Hive login required) and Hive Detect web tool; no cap stated. Free API quota for AI detection not published (every AI Detection pricing line is Contact Sales). | Text processed in chunks of 2,048 characters; maximum length not published | thehive.ai | |
| GLTR | Free and open source (Apache License 2.0): public demo at demo.gltr.io with no account, and the server runs locally from the GitHub repository (python server.py) | Any textual input pasted into the demo; no character or word limit is published | github.com, read 9 November 2026 | |
| GPT-2 Output Detector | Free: MIT-licensed weights and code on GitHub and the model on Hugging Face, run locally (python -m detector.server, web UI at localhost:8080); the hosted Hugging Face demo is paused | The local web UI accepts pasted text with no published character limit; evaluated on 510-token examples | github.com, read 9 November 2026 | |
| Codequiry | Codequiry Free: $0/mo, unlimited peer similarity checks within a class, no card needed; web, GitHub and AI detection are not included, so AI code detection has no free tier | per month | Source code by drag and drop, paste, ZIP upload or LMS import in 65+ programming languages; checks metered per submission; no file size limit published | codequiry.com/pricing, read 9 November 2026 |
| Turnitin | None. AI writing detection is only available to customers that license Turnitin Originality (or the AI writing add-on for iThenticate 2.0). | 300 to 30,000 words of prose; files under 100 MB | guides.turnitin.com |
Which free AI detectors state no limit, and what does the word cover?
Scribbr's statement covers the number of checks. "Unlimited free AI checks, no sign-up required" is the whole of the free-tier wording on the detector page read 8 November 2026 (scribbr.com), and the same page says the free detector covers GPT-2, GPT-3 and GPT-3.5 "with average accuracy" and that the highest accuracy Scribbr found in any free tool was 68%. Phrasly's statement covers checks, characters and months, with one floor: the web tool asks for at least 30 words and states no character limit, while the Business API asks for at least 50 words and caps a request at 15,000 characters (phrasly.ai, read 8 November 2026). Phrasly's terms, updated 12 October 2026, grant the company a perpetual licence over "Contributions" while the detector page says analysed text is deleted immediately (phrasly.ai/terms/privacy, read 8 November 2026); both statements are quoted on the Phrasly card. Two pages added 9 November 2026 read the free tiers by a different unit: the free API question asks which free allowances reach the API, and the free checks per day ranking sorts the four vendors that state a daily figure in checks.
Two more free tiers have no stated cap on checks but a cap per check. Sapling's free plan says the count of checks per period is not capped and each check covers the first 2,000 characters (sapling.ai/pricing, read 8 November 2026). Hive's free Chrome extension and web tool state no cap and process text in chunks of 2,048 characters (thehive.ai, read 8 November 2026). QuillBot's "no word limit" applies to Premium at $8.33 USD per month billed annually, checked 8 November 2026, while the free scan caps at 1,200 words and 6 scans a day (quillbot.com).
Two open-source tools added to the index on 9 November 2026 state no cap of any kind because they run on the reader's own machine, and neither states an allowance: GLTR's public demo at demo.gltr.io takes pasted text with no published character or word limit, and the Apache-licensed server runs locally from the GitHub repository (github.com, read 9 November 2026); OpenAI's GPT-2 Output Detector ships MIT-licensed weights and code that run locally, with the hosted Hugging Face demo paused (github.com, read 9 November 2026). The other four cards added that day are capped or closed: AIDetectPlus gives 1,000 credits one time and a 3,000-character home page box with no account (aidetectplus.com); WasItAI 10 images per month (wasitai.com/api); Reality Defender 50 image scans per month on its free API plan (realitydefender.com/api); and Codequiry's free plan excludes AI detection (codequiry.com/pricing), all read 9 November 2026.
Which free tier allows the most text?
By month, ZeroGPT: a words allowance of 1,250,000 per month on the FREE column of the pricing compare table, with each detection capped at 15,000 characters (zerogpt.com/pricing, read 8 November 2026). GPTZero's free plan covers 10,000 words per month per the vendor blog of 25 October 2026 (gptzero.me). Those two and Turnitin, at zero, are the only monthly word figures in the index, and the free tiers ranking sorts them; the other 19 are listed there as the vendor words them, never converted, and WasItAI's 10 images and Reality Defender's 50 scans per month are counts of files, not words.
By single check, GPTZero with a free account: texts up to 150,000 characters or a batch of 250 files, against 10,000 characters per scan without an account (gptzero.me/faq, read 8 November 2026). Copyleaks' free scan takes up to 25,000 characters (copyleaks.com), JustDone's scan up to 15,000 words (justdone.com) and ZeroGPT's free detection 15,000 characters, all read 8 November 2026. The ranking by input limit sorts every card on the maximum per check.
Three of the free tiers on this page are compared field by field on ZeroGPT vs Scribbr vs QuillBot, added 9 November 2026: 15,000 characters per detection and 1,250,000 words a month, "unlimited", and 1,200 words per scan with 6 scans a day, each in the vendor's own unit, beside the one study that tested two of the three.
What do the studies say about free detectors?
Walters 2023 is the one record in the index that separates free from paid: the six detectors that required a subscription averaged 87% correct on 126 documents against 77% for the ten that did not (DOI 10.1515/opis-2022-0158, read 8 November 2026). The free tools did not all sit at the bottom: ZeroGPT, free, classified 87% of the 126 correctly with a 2% false positive rate on 42 human papers, and Scribbr, free, scored 88% with the same 2% rate in Walters 2023. The Walters 2023 record carries the full table. Of the two detectors with an uncapped free tier, Scribbr has that one study record and no study in the index has tested Phrasly; Phrasly states an accuracy rate of 99.8% on fully AI-generated text and adds that "False positives are inevitable" (phrasly.ai, read 8 November 2026). The ranking by independent testing lists the ten detectors with a record.
How should a reader read a free tier?
Read the unit before the number, and read the floor as well as the ceiling: a free tier with no cap still refuses or warns below the vendor's minimum, which the question page on short texts tables for every card, from Phrasly's 30 words to Turnitin's 300. ZeroGPT states words per month in a compare table and characters per detection in the plan card; GPTZero states words per month in a blog post and characters per scan in the FAQ; Copyleaks counts credits of 250 words; Winston AI and Originality.ai count credits that do not renew (gowinston.ai/pricing, originality.ai/pricing, read 8 November 2026). A one-time total of 10,000 words is not a monthly allowance, and the index records the vendor's period rather than guessing one, under the rule on the methodology page. The home board shows which AI detectors exist and what each one gives away free.
Whether the free check needs an account is a separate statement: 15 cards state that it does not, on the no-account view, added 9 November 2026, with Scribbr and Phrasly the two stating no limit as well.
Beside the free routes above sit four paid tiers sold under a student name, from Isgen Academic at $8 a month to ZeroGPT EDU, which the student plan question lists with the nine institution-only education tiers, read 10 November 2026.
Questions about free AI detectors with no limit
Is there a free AI detector with no word limit?
Phrasly states "no character limits" and no monthly scan caps for its free web tool, with a floor of 30 words per text (phrasly.ai, read 8 November 2026). Scribbr states unlimited free checks with no sign-up (scribbr.com). QuillBot's "no word limit" is a Premium feature at $8.33 USD per month billed annually, checked 8 November 2026 (quillbot.com/premium).
Which free AI detector allows the most words per month?
ZeroGPT, at a stated 1,250,000 words per month on the FREE plan, with each detection capped at 15,000 characters (zerogpt.com/pricing, read 8 November 2026). GPTZero's free plan covers 10,000 words per month per the vendor blog of 25 October 2026 (gptzero.me). No other vendor states a monthly figure.
Are the unlimited free AI detectors accurate?
Scribbr scored 88% of 126 documents with a 2% false positive rate on 42 human papers in Walters 2023 (DOI 10.1515/opis-2022-0158), and Scribbr itself says the highest accuracy found in a free tool was 68% (scribbr.com, read 8 November 2026). No study in the index has tested Phrasly; Phrasly states an accuracy rate of 99.8% on fully AI-generated text.
Do free tiers change?
Yes, and the index records the date each one was read. GPTZero's 10,000 words per month comes from a blog post dated 25 October 2026, two weeks before the 8 November 2026 read (gptzero.me). All free tiers are rechecked on 8 December 2026, and any change is written to the corrections log.
Sources
All read 8 November 2026.
- Scribbr AI detector: https://www.scribbr.com/ai-detector/
- Phrasly AI detector: https://phrasly.ai/ai-detector
- Phrasly privacy and terms: https://phrasly.ai/terms/privacy
- ZeroGPT pricing: https://www.zerogpt.com/pricing
- GPTZero blog, 25 October 2026: https://gptzero.me/news/best-ai-detectors
- GPTZero FAQ: https://gptzero.me/faq
- QuillBot AI detector: https://quillbot.com/ai-content-detector
- QuillBot Premium: https://quillbot.com/premium
- Pangram: https://www.pangram.com/
- Copyleaks AI detector: https://copyleaks.com/ai-content-detector
- Sapling pricing: https://sapling.ai/pricing
- Winston AI pricing: https://gowinston.ai/pricing/
- Originality.ai pricing: https://originality.ai/pricing
- Proofademic pricing: https://proofademic.ai/pricing/
- Walter Writes: https://walterwrites.ai/
- Grammarly plans: https://www.grammarly.com/plans
- JustDone AI detector: https://justdone.com/ai-detector
- Hive AI-generated content detection: https://thehive.ai/apis/ai-generated-content-classification
- Turnitin AI writing detection FAQs: https://guides.turnitin.com/hc/en-us/articles/28477544839821
- Walters 2023: https://doi.org/10.1515/opis-2022-0158
- GLTR repository: https://github.com/HendrikStrobelt/detecting-fake-text (read 9 November 2026)
- GPT-2 Output Detector repository: https://github.com/openai/gpt-2-output-dataset/tree/master/detector (read 9 November 2026)
- AIDetectPlus AI detector: https://aidetectplus.com/ai-detector (read 9 November 2026)
- Codequiry pricing: https://codequiry.com/pricing (read 9 November 2026)
- WasItAI API and plans: https://wasitai.com/api (read 9 November 2026)
- Reality Defender API plans: https://www.realitydefender.com/api (read 9 November 2026)
Revision log: 2026-11: page created; 2026-11-09: 22-card recount; 2026-11-09: short-text question page linked; 2026-11-09: three-way free detector comparison linked (fifth wave); 2026-11-09: free API question and free checks per day ranking linked (seventh wave); 2026-11-09: eighth-wave pages linked; 2026-11-10: twelfth-wave pages linked
Related pages: Is JustDone's AI detector legit or accurate? What is published, How many AI detectors exist? The index count and every study's count, AI detectors ranked by the free checks per day the vendor states and Questions about AI detectors, answered from the index.