O
OAI content detection, plagiarism and fact checking for publishers and educators
Free, from $12.95/mo
GPTZero vs LanguageTool
Pricing, features, platforms and who each one suits — side by side.
G
Choose GPTZero if…
- you're in its core audience: teachers and educators, students
L
Choose LanguageTool if…
- you want open source you can self-host or audit
- you work on Windows, macOS, iOS
- you're in its core audience: students, professional writers
Side by side
Feature GPTZero LanguageTool
Pricing modelFreemiumFreemium
Starting price——
Free plan
Free trial
API
Open source
Trains AI on your content—No
Security and complianceSOC 2 Type II, CCPA, GDPRGDPR
Plagiarism checker—
Writing replay—
Docs/LMS integration—
PlatformsWeb, Chrome, APIWeb, Chrome, Windows, macOS, iOS, API
CategoryAI Detection & HumanizersGrammar & Proofreading
CompanyGPTZero LLCLearneo, Inc.
Based inUnited StatesUnited States
Founded20232003
Part of——
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
L LanguageTool
- Grammar, spelling, punctuation and style checking
- AI sentence paraphrasing in several tones
- Support for 30+ languages and dialects
- Browser add-ons for Chrome, Edge, Firefox, Opera, Safari
- Plugins for Google Docs, Word, Pages, LibreOffice
- Personal dictionary and Picky Mode
- Team style guides and shared dictionaries
- Proofreading API with daily call-limit plans
Plans and prices
From each vendor's site. Prices change — confirm before buying.
GPTZero
FreeFree
Professional TeamPrice not shown on page
LanguageTool
BasicFree
PremiumPrice not shown on page
TeamsPrice not shown on page
BusinessCustom
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
LanguageTool
- Free Basic plan is available
- Supports 30+ languages and dialects
- Many integrations, including browsers, office suites and email clients
- Source code is published on GitHub
- Free plan is limited to 2,000 characters per text field
- Free plan allows only 3 AI rephrasings per day
- Prices did not display on the pricing pages
- Outlook add-on is still in beta
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Built from each vendor's public website; we haven't tested them hands-on. Editorial policy