O
OAI content detection, plagiarism and fact checking for publishers and educators
Free, from $12.95/mo
GPTZero vs Grammarly
Pricing, features, platforms and who each one suits — side by side.
G
Choose GPTZero if…
- you need an API to build on
- you're in its core audience: teachers and educators, students
G
Choose Grammarly if…
- you work on Windows, macOS, iOS
- you're in its core audience: students, professionals
Side by side
Feature GPTZero Grammarly
Pricing modelFreemiumFreemium
Starting price——
Free plan
Free trial
API
Open source
Trains AI on your content—Yes, unless you opt out
Data retention—Saved documents kept until you delete them or your account
Security and complianceSOC 2 Type II, CCPA, GDPRSOC 2 Type II
Plagiarism checker—
Writing replay—
Docs/LMS integration—
PlatformsWeb, Chrome, APIWeb, Windows, macOS, iOS, Android, Chrome
CategoryAI Detection & HumanizersGrammar & Proofreading
CompanyGPTZero LLCSuperhuman Platform Inc.
Based inUnited StatesUnited States
Founded20232009
Part of—Superhuman
Key features
G GPTZero
- Detects text from ChatGPT, Claude and Gemini
- Highlights passages likely to be AI-generated
- Writing Replay shows how a document was typed
- Plagiarism checker for unattributed content
- Hallucination detector
- Grammar check and writing feedback
- Google Docs, Google Classroom, Canvas and Zapier integrations
- API with code samples in 17 languages
G Grammarly
- Real-time spelling, grammar and clarity checks
- Paragraph and full-sentence rewrites
- Tone suggestions for different audiences
- Reader Reactions predicts how readers respond
- AI Detector and Humanizer agents
- Plagiarism checker and citation generator
- Works in MS Office, Google Docs and browsers
- Enterprise style guides, brand tones and DLP
Plans and prices
From each vendor's site. Prices change — confirm before buying.
GPTZero
FreeFree
Professional TeamPrice not shown on page
Grammarly
Free€0
Pro€12/member/mo billed annually (€30 billed monthly)
EnterpriseCustom
Strengths and limitations
GPTZero
- Free tier available to get started
- Integrates with Google Docs, Google Classroom, Canvas and Zapier
- Fully supports five languages
- States SOC 2 Type II, FERPA, GDPR and CCPA compliance
- Individual plan prices could not be read from the pricing page
- Team plan requires at least 2 seats and payment by card only
- No native mobile apps mentioned
Grammarly
- Free plan includes grammar checks and 100 AI prompts a month
- Available on desktop, mobile, browser extensions, MS Office and Google Docs
- Pro includes plagiarism and AI-text detection
- Enterprise offers SSO, SCIM, BYOK and data loss prevention
- Pro costs €30 when billed monthly versus €12 billed annually
- Free plan is limited to 100 AI prompts per month
- Enterprise pricing is not published
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Built from each vendor's public website; we haven't tested them hands-on. Editorial policy