AI Detector Pricing Compared: What Every Tool Actually Costs in 2026
Every major AI detectors pricing in one place, checked against vendor pricing pages in July 2026. Free tiers, cheapest paid plans, what a credit actually buys, per-essay costs, and which education prices are published versus quote-only.
Nobody neutral maintains an AI detector price list. Every vendor prices in a different unit, words, credits, scans or characters, several hide pricing behind quote forms, and third-party listicles copy each other's stale numbers for months. So we checked every major vendor's own pricing page in July 2026 and put the results in one place.
Two honest notes before the table. We sell one of these tools, and our prices are in the table with everyone else's. And several vendors render pricing dynamically or by region, so treat this as a dated snapshot, follow the links, and tell us if something has moved.
The pricing table (checked July 2026)
Prices are in the currency each vendor displays, USD for most, GBP for us. Annual-billing figures are the per-month equivalent the vendor advertises.
What checking one 1,000-word essay actually costs
Vendors price in incompatible units on purpose, so here is the same question asked of every tool with a clear published quota: on the cheapest paid plan, what does one 1,000-word essay cost to check? This is arithmetic on the listed prices above, nothing more.
Two caveats. Scan-priced tools (ours, Pangram's app plans) charge per document rather than per word, so long documents favour them and short ones do not. And a cheap scan is not automatically good value: an unexplained percentage can cost you far more in one wrongly handled accusation than the tool ever saved. Our view on what a defensible result looks like is in our false-positive benchmark.
Which free tiers are real
- Genuinely useful free tiers: Scribbr (unlimited checks, capped at 1,200 words each, no account needed), ZeroGPT (unlimited-ish with ads), GPTZero (10,000 words/month), QuillBot (6 scans/day), Grammarly (free on-site detector), Pangram (4 scans/day), and ours (3 scans/day with a free account).
- Trials dressed as free tiers: Winston's 14 days. Fine, but it expires.
- Not really free: Originality.ai has no standing free tier. Turnitin has nothing below an institutional contract.
For a teacher doing occasional spot checks, a real free tier plus a second-opinion tool is a defensible workflow that costs nothing. Our free detectors guide covers that in detail.
The education pricing problem
Here is the pattern worth noticing: almost every vendor sends schools to a quote form. Turnitin publishes no pricing at all. GPTZero, Copyleaks, Pangram and Grammarly all price education by negotiation. That is not an accident; quote-based pricing means the school with the weakest procurement experience pays the most.
We publish ours instead: Department at £499 a year for up to 10 staff seats, Whole School at £1,499 a year, sized deliberately so a head of department can approve it without a procurement cycle. If a vendor will not tell you a price until you have been through a sales call, that is information about the sales process, not the product.
How to read detector pricing before you buy
- Convert everything to your real usage. A five-teacher department checking 60 essays a month has no use for 300,000 words of quota, and a content agency has no use for 50 scans. The unit matters more than the headline.
- Check what the paid tier actually adds. Across most tools, paying buys volume, batch, API and reports, not a better detection engine. If the free tier answers your volume, keep it.
- Watch the annual-billing asterisk. Most advertised prices are the annual-commitment rate; month-to-month is often 40 to 80 percent higher.
- Price the false positive, not just the scan. The real cost of a detector is not the subscription, it is what happens when a flag is wrong. A tool that explains its flags and publishes its false-positive rate is cheaper in the way that matters. That argument, with our numbers, is here.
We will re-check this page as vendors move. If a price above is out of date, the vendor links are the source of truth, and we would genuinely like to know.
Frequently asked questions
How much does an AI detector cost in 2026?
Cheapest paid plans run from about $8 to $25 per month. GPTZero Essential is $8.33/month billed annually for 150,000 words, ZeroGPT Pro is $9.99/month, Winston AI Essential is $10/month for 80,000 words, Originality.ai Pro is $14.95/month, Pangram is $20/month for 600 scans, and Is It AI Teacher Lite is £9.99/month for 50 explained scans. Turnitin publishes no pricing at all and sells only institutional licences. Most tools also offer usable free tiers for occasional checks.
Which AI detector has the best free tier?
It depends on your volume pattern. Scribbr allows unlimited free checks capped at 1,200 words each with no account. GPTZero gives 10,000 words per month. QuillBot allows 6 scans a day, Pangram 4 a day, and Is It AI 3 a day with a free account, with flagged-passage explanations included. ZeroGPT is free with ads. Winston AI has no standing free tier, only a 14-day trial, and Originality.ai has none.
How much does Turnitin AI detection cost?
Turnitin publishes no pricing. It is sold only as an institutional licence, quoted per institution by size and features, and AI writing detection is not included in base Turnitin Similarity: it requires the paid Originality add-on. There is no individual teacher licence at any price. Schools comparing costs should request the AI detection uplift as a separate line item in the quote.
What does it cost to check one 1,000-word essay?
On the cheapest paid plans with published quotas: about 5 cents via Pangram's API, about 6 cents on GPTZero Essential, about 7 cents on Originality.ai Pro, and about 13 cents on Winston AI Essential. Scan-priced tools charge per document instead: about 3 cents per scan on Pangram Individual, 10 pence on Is It AI Teacher Pro and 20 pence on Teacher Lite. A low per-check price does not guarantee value, though: one badly handled false positive costs more than any subscription.
Why do AI detectors price in credits instead of a simple monthly fee?
Credits let vendors meter different features at different rates from one balance, for example Originality.ai charges 1 credit per 100 words for AI-only checks but 2 for AI plus plagiarism, and Winston charges 1 credit per word for AI detection but 2 for plagiarism. It also makes comparison between tools genuinely difficult, which suits vendors. The fix is to convert every plan into your own expected monthly checks before comparing prices.