Head to head · Writing · updated Oct 25, 2026
QuillBot vs GPTZero
QuillBot scores 11 to GPTZero's 10 on public evidence for AI content detection, and they rank #2 and #4 there. Both are free to start. Numbers below are the same public signals the ranking uses, recomputed nightly — nothing here is sponsored.
QuillBot
A paraphraser, grammar checker, summarizer and AI detector/humanizer popular with students.
+ The paraphraser's mode slider (fluency, formal, simple, creative) is the fastest way to rework a clumsy paragraph.
− Paraphrased text sometimes changes meaning, and its humanizer and detector are unreliable against serious detection tools.
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| QuillBot | GPTZero | |
|---|---|---|
| Evidence score / 100 | 11 | 10 |
| GitHub stars | closed source | closed source |
| Hacker News stories, 30d | 0 | 0 |
| Release-feed mentions, 30d | 0 | 0 |
| Last activity | – | – |
| Pricing | Free tier · Premium from $4.17/mo billed annually | Free tier · Essential from $8.33/mo billed annually |
| Platforms | web, mac, windows, ios, android, chrome-extension | web, chrome-extension, api |
| Maker | QuillBot (Learneo) | GPTZero |
Which one?
Pick QuillBot if
- you want the stronger public evidence (11 vs 10)
- you need it on android, ios, mac
Best for paraphrasing and quick rewrites.
Pick GPTZero if
- you need it on api
Best for classroom AI-writing checks.