Head to head · Writing · updated Oct 25, 2026
Turnitin vs GPTZero
Turnitin scores 12 to GPTZero's 10 on public evidence for AI content detection, and they rank #1 and #4 there. Only GPTZero has a free tier. Numbers below are the same public signals the ranking uses, recomputed nightly — nothing here is sponsored.
Turnitin
The dominant academic plagiarism checker, with an AI-writing indicator built into its similarity reports.
+ Already deployed at most universities, so AI scores appear inside the workflow instructors use.
− No individual access, and its AI indicator has led to disputed accusations against students.
GPTZero
An AI-text detector for educators with sentence-level highlighting and a writing-process report.
+ Highlights which sentences look AI-generated and offers a Google Docs writing replay as supporting evidence.
− Like all detectors it produces false positives, particularly on non-native English writers.
Side by side
public evidence| Turnitin | GPTZero | |
|---|---|---|
| Evidence score / 100 | 12 | 10 |
| GitHub stars | closed source | closed source |
| Hacker News stories, 30d | 2 | 0 |
| Release-feed mentions, 30d | 0 | 0 |
| Last activity | – | – |
| Pricing | Paid · Institutional licensing only | Free tier · Essential from $8.33/mo billed annually |
| Platforms | web | web, chrome-extension, api |
| Maker | Turnitin | GPTZero |
Which one?
Pick Turnitin if
- you want the stronger public evidence (12 vs 10)
Best for institution-wide academic integrity.
Pick GPTZero if
- you want a free tier to start on
- you need it on api, chrome-extension
Best for classroom AI-writing checks.