Know what you are paying for.
Free sample tools need no account at all. Paid plans come in three terms: by the month, by the four-month semester, or by the year, which is the cheapest per month. High School starts at $9.99 a month, College at $24.99 and Pro at $44.99, and every plan opens with a 7-day trial that does not ask for a card. The trial takes no payment details, so there is nothing to cancel if you decide Cortex is not for you.
Priced by the term, not the month.
Every plan starts with a 7-day trial and no card. Allowances run per 30-day cycle.
Save up to 33% by paying for the year. Semester billing lands in between.
Free trial
Anyone, for a week
7 days
No card. Everything switched on, capped.
- 2,000 humanized words
- 15 detector checks
- 15 Capture and Solve runs
- Split View and the extension
High School
Save 20%GCSEs, A-levels, AP and IB
/ month
$47.96 billed every four months. Save $12 against monthly.
- 10,000 humanized words a month
- 45 detector checks
- 40 Capture and Solve runs
- Split View and the extension
College
Best fit for most studentsUndergraduate and taught postgraduate
/ month
$119.96 billed every four months. Save $20 against monthly.
- 35,000 humanized words a month
- 120 detector checks
- 90 Capture and Solve runs
- Split View and the extension
Pro
Save 12%Dissertation and thesis terms
/ month
$211.96 billed every four months. Save $28 against monthly.
- 70,000 humanized words a month
- 220 detector checks
- 180 Capture and Solve runs
- Priority processing
BYOK You already pay a model provider
Bring your own API key and Cortex stops metering you entirely. Your provider bills you directly, at their rates and their limits.
| Compare | Free trial | High School | College | Pro | BYOK |
|---|---|---|---|---|---|
| Humanized words per month | |||||
| Detector checks per month | |||||
| Capture and Solve runs | |||||
| Split View | Included | Included | Included | Included | Included |
| Chrome extension | Included | Included | Included | Included | Included |
| Priority processing | Not included | Not included | Not included | Included | Not included |
How terms and allowances work
A semester is four months and renews once. A cycle is 30 days from your billing date, and allowances reset each cycle rather than rolling over. Your dashboard shows what is left and when it resets.
Humanize is metered by words. Detect and Capture and Solve are metered by run, and a run that fails is not counted.
Detector results are estimates from GPTZero, not proof of authorship. On BYOK your provider's own rate limits and pricing apply and Cortex does not meter you at all.
What the allowances mean
Free sample limits are 300 words for Humanize and 1,000 words for Detect per request, with no account. Paid allowances are counted per 30-day period and shown live on your dashboard, so you can see what you have used rather than guessing. A per-request limit is not a promise of unlimited service, and we do not advertise savings we have not actually applied. Cancellation and refund terms are set out in the terms.