Grammarly vs LanguageTool

Grammarly

• People who write across many apps and want the same checks in each
• Teams of up to 149 that need a shared style guide and brand tone
• Students who want citation, plagiarism and AI-detection checks in one editor

LanguageTool

• People who write in several languages, not only English
• LibreOffice, Thunderbird and Apple Pages users who want a checker add-on
• Developers who need a proofreading API or a checker they can host themselves

Grammarly

• The Free plan is capped at 100 AI prompts a month and leaves out full-sentence rewrites and tone adjustments.
• Pro costs $30 per member a month on monthly billing, against $12 a month when billed annually.
• Pro stops at 149 seats; larger organizations need Enterprise, which is priced through sales.
• Advanced grammar, clarity and tone suggestions cover six languages; the other supported languages get spelling and basic grammar only.

LanguageTool

• The free Basic plan checks 2,000 characters per text field and allows 3 AI rephrasings a day.
• There is no free trial of Premium; LanguageTool offers a 14-day money-back guarantee instead.
• Monthly billing is $24.90, more than four times the per-month cost of the annual plan.
• Apps are listed for Windows, macOS and iOS; no Android app appears on the site.

Grammarly

Grammar, spelling and tone checks

Corrects spelling and grammar and shows the tone of a message on every plan. Full-sentence rewrites and one-click tone adjustments are part of Pro.

Works inside other apps

Desktop apps for Windows and Mac, extensions for Chrome, Safari, Firefox and Edge, and iPhone, iPad and Android apps bring suggestions into tools such as Gmail, Google Docs, Word and Slack.

Docs and AI agents

Docs is a browser-based document editor with agents including AI Grader, Citation Finder, Reader Reactions, Humanizer and Paraphraser. Some agents are limited to Pro.

Generative AI prompts

Drafts and reworks text from a prompt. The allowance is 100 prompts a month on Free, 2,000 per member on Pro and unlimited on Enterprise.

Plagiarism and AI detection

Scans a document for text that matches other sources and for passages likely to be AI-generated. The plans page lists both checks under Pro.

Team style controls

Pro team accounts get style guides, brand tones, knowledge share, snippets and usage analytics, so a group writes with the same terms and voice.

LanguageTool

Grammar, spelling and style checks

Checks grammar, punctuation, spelling, casing and style. Premium adds more than 20,000 extra checks for English, German, French, Spanish, Dutch, Polish and Portuguese.

AI paraphrasing

Rephrases a sentence to be more formal, more fluid or shorter. Basic accounts get 3 rephrasings a day and Premium removes the limit.

Long-text checking

Premium checks up to 150,000 characters per text field, against 2,000 on the Basic plan.

Style guide and dictionaries

Custom rules enforce consistent wording. Teams share a style guide and a dictionary of approved terms, with admins deciding who can add to them.

Add-ons and apps

Browser add-ons for Chrome, Edge, Firefox, Safari and Opera, plugins for Google Docs, Word, Apple Pages and LibreOffice, email add-ons, and apps for Windows, macOS and iOS.

Open-source core and API

The core checker is open source, with code on GitHub, and users can set up their own LanguageTool server. A hosted Proofreading API accepts up to 60,000 characters per request.

Grammarly

• Free$0

  Spelling and grammar corrections, tone detection and 100 AI prompts a month, for individuals.

• Pro$12

  per member / month, billed annually ($30 billed monthly)

  Full-sentence rewrites, tone adjustments, style guides and brand tones, and 2,000 AI prompts a month. Sold for 1 to 149 seats.

• EnterpriseCustom

  Unlimited members and AI prompts, dedicated support, confidential mode, granular roles and data loss prevention. Sold through Superhuman Go.

LanguageTool

• Basic$0

  Grammar, punctuation and spelling checks on up to 2,000 characters per text field, with 3 AI sentence rephrasings a day.

• Premium$5.83

  per month, billed annually ($69.90); $24.90 billed monthly

  Up to 150,000 characters per text field, 20,000+ extra checks, unlimited AI paraphrasing and a personal style guide. Also $49.90 a quarter or $119.80 for 2 years.

• Teams$66.40

  per user / year, for a team of 2 users

  Every Premium feature plus user management, a team style guide and a team dictionary. Sold from 2 users, with a lower per-user price for larger teams.

Grammarly

• Annual discount

  Save up to 60% with yearly billing

  Pro is $12 per member a month when billed annually and $30 when billed monthly. The plan toggle advertises a saving of up to 60% on yearly billing.

• Education

  Discounts for educational institutions

  The plans page FAQ says Grammarly offers discounts for educational institutions. Grammarly for Education is quoted through its education sales team.

LanguageTool

• Annual discount

  Longer billing terms cost less per month

  Premium is $24.90 billed monthly, $49.90 a quarter, $69.90 a year or $119.80 for two years, which works out to about $5.83 and $4.99 a month on the two longest terms.

• Education

  Up to 20% off for students and educators

  Students, teachers and professors can claim an educational discount of up to 20% off a Premium subscription.

• Other savings

  Team seats priced below individual plans

  On Teams, each seat costs less than the $69.90 individual annual price: $66.40 per user for 2 users and $62.91 per user from 10 users.

• Other savings

  Limited-time 20% discount on Premium

  The pricing page was advertising a limited-time 20% discount on Premium, with a countdown, when it was checked on 2026-10-05.