LanguageTool
LanguageTool (LanguageTooler GmbH) is an AI-based multilingual grammar, style, and paraphrasing platform delivered via freemium web, browser, desktop, mobile, and API surfaces to consumers, teams, and 2,000+ enterprises across 30+ languages.
- Company typePrivate
- Founded2003
- HeadquartersPotsdam, Germany
- Headcount11–50
- GTM typeB2B and B2C
- OfferingSoftware
What LanguageTool does
LanguageTool (legally LanguageTooler GmbH, headquartered in Hamburg with an engineering office in Potsdam) is a commercial AI-based writing assistance platform that originated as an open-source grammar-checking project in 2003 and has since accumulated 143+ contributors, 30+ supported languages, and millions of active users. Its core offering performs grammar, spelling, punctuation, style, tone, typography, and language-variety checks in real time, supplemented by an AI-powered paraphrasing tool that rephrases sentences across multiple registers. The product is delivered through a freemium model: a no-registration web editor, browser extensions on Chrome, Firefox, Edge, Safari, and Opera, native Windows and macOS desktop applications launched in 2024, an iOS app, and integrations with Gmail, Outlook, Apple Mail, Thunderbird, Google Docs, Microsoft Word, Apple Pages, and LibreOffice. A self-hostable open-source server (Apache 2.0) and a commercial Proofreading API extend the platform to developers and organizations with data-residency or custom-integration requirements.
The company monetizes via four subscription streams: Premium for individual users (monthly or annual billing with student/teacher discounts), Premium for Teams (annual per-seat pricing with shared style guides and team dictionaries), a Business/Enterprise tier offering GDPR-conform solutions for 2,000+ organizations including the BMW Group, European Union institutions, Spiegel, Deutsche Presse-Agentur, Max-Planck-Gesellschaft, and JetBrains, and the Proofreading API. Distribution is product-led and self-serve for consumers and SMBs, with a direct enterprise sales motion layered on top. The Terms of Service describe LanguageTool as 'a Learneo, Inc. business,' indicating an operational relationship with Learneo that is not separately disclosed. Development has been supported by the European Union, the European Regional Development Fund, and the European Social Fund, and the company maintains technology partnerships with Syncro Soft (oXygen XML editor) and ej-technologies (JProfiler). No external funding rounds, acquisitions, patents, or trademarks are disclosed.
Operationally, the company is described as remote-first with active hiring across global linguistic and machine-learning roles, processes 20M+ texts daily, and reports user bases of 3M+ on Chrome, 4M+ on Safari, and 1M+ on each of Firefox and Edge. Leadership comprises Managing Directors Stephen Van Horne and Jennifer Seidel. The platform's competitive posture combines a long-running open-source community, broad cross-surface distribution, multilingual breadth, and EU data-residency positioning to serve individual, academic, professional, and enterprise writing-assistance use cases.
LanguageTool firmographics
Firmographics- Name
- LanguageTool
- Legal name
- LanguageTooler GmbH
- Website
- https://languagetool.org
- Company type
- Private
- Founded year
- 2003
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- LanguageTool (LanguageTooler GmbH) is an AI-based multilingual grammar, style, and paraphrasing platform delivered via freemium web, browser, desktop, mobile, and API surfaces to consumers, teams, and 2,000+ enterprises across 30+ languages.
- Ownership category
- akta.pro rank
LanguageTool industry classification
Industry- Product category
- Writing Assistance Software
- NAICS
- Custom Computer Programming Services (541511), Educational Support Services (61171)
- SIC
- Services-Prepackaged Software (7372), Services-Computer Programming, Data Processing, Etc. (7370)
- akta.pro primary industry
- Content Generation & Writing Assistance (copy, emails, reports) (HDAAADAG)
Keywords
Where LanguageTool is headquartered
LocationHeadquarters
- HQ city
- Potsdam
- HQ country
- Germany
- HQ region
- Europe
Offices2 records
Markets served
LanguageTool business model
Business model- GTM type
- B2B and B2C
- Offering type
- Software
- Cost components
- Technology or R&D, Personnel, Infrastructure, Marketing or Sales, Operations
Revenue model
- Premium Individual Subscription: Subscription-based premium features including unlimited paraphrasing, 20,000+ additional checks for major languages, 150,000 character text limit, custom style guide, and browser add-on access. Available as monthly, quarterly, or annual billing with automatic renewal.
- Premium Teams Subscription: Team accounts for up to 20+ members with all Premium features plus shared style guide, team dictionary, and user management. Per-user pricing with annual billing.
- Proofreading API: API access for businesses and developers to integrate grammar checking into their own applications
- Enterprise/Business Solutions: GDPR-compliant solutions for organizations with team management, consistent brand voice, and enterprise-grade features
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Freemium | Others | Free tier with basic checking |
| Subscription | Monthly | Premium for individual users |
| Subscription | Annual | Annual Premium subscription |
| Subscription | Annual | Premium Teams (up to 20+ members) |
Go-to-market motion4 records
Distribution channels8 records
Marketing channels7 records
LanguageTool product offering
Product offeringCore offering
LanguageTool provides an AI-based grammar, spelling, punctuation, and style checker that operates across 30+ languages, available as a free web editor and via Premium subscriptions. The company complements the core checker with an AI-powered paraphrasing tool, a proofreading HTTP API for developers, and a dedicated GDPR-compliant Business tier for organizations. The underlying grammar engine is open-source (Apache 2.0) and is distributed via browser extensions, desktop apps, mobile apps, and office/email integrations.
Product overview
LanguageTool is a unified AI-based writing assistant platform that offers grammar checking, spell checking, punctuation correction, style suggestions, and AI-powered paraphrasing across 30+ languages. The core product is the web-based Grammar Checker, complemented by a Paraphrasing Tool. The platform offers Premium and Teams subscription tiers for individuals and organizations respectively. LanguageTool provides extensive integration options through browser add-ons (Chrome, Firefox, Edge, Safari, Opera), email add-ons (Gmail, Outlook, Apple Mail, Thunderbird), and office plugins (Google Docs, Microsoft Word, Apple Pages, LibreOffice). Native desktop applications are available for Windows and macOS, along with an iOS mobile app. For developers, LanguageTool offers a Proofreading API and open-source software for self-hosting. The Business tier provides GDPR-conform solutions for enterprise teams.
Differentiator
Problem solved
Functional benefit
Products and services
- LanguageTool Grammar Checker AI-based grammar, spelling, punctuation, style, and casing checker that provides real-time context-aware suggestions across 30+ languages and dialects, available through a free web editor and browser extensions.
- Paraphrasing Tool
Quantifiable outcome
- 20M+ texts improved using LanguageTool every day
- +2 more outcomes
Companies that use LanguageTool
Customer profileNamed customers15 records
Segments5 records
Ideal customer profiles5 records
LanguageTool technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- Yes
- API docs
- API detail
Core technology
AI maturity
App detail
Integration18 records
AI capability4 records
Feature8 records
LanguageTool partnerships and signals
Strategic signalPartnerships
One partnership is on record.
- Community (forum sponsors)minorCommunity sponsors the LanguageTool forum through Communiteq.
Scale indicators10 records
Recent moves6 records
Expansion highlights6 records
LanguageTool competitors and assessment
Company assessmentDirect peers
- Grammarly: Grammarly is the category leader in AI-based grammar and writing assistance, offering browser extensions, desktop apps, and enterprise solutions. It is the most direct competitor to LanguageTool with a comparable product surface, target audience, and PLG-to-enterprise motion.
- QuillBot: QuillBot is an AI writing platform whose core offering — paraphrasing and sentence rephrasing — directly overlaps with LanguageTool's Paraphrasing Tool. It serves similar students, professionals, and enterprise customers via freemium and subscription tiers.
- ProWritingAid: ProWritingAid offers grammar, style, and writing-improvement assistance with deep editor integrations, targeting professional writers, students, and enterprises. Comparable to LanguageTool in product surface (premium subscription, integrations) and customer base (writers, academics).
- Wordtune: Wordtune provides AI-powered paraphrasing, rewriting, and grammar assistance as a browser extension and writing assistant. It is a direct competitor to LanguageTool's AI paraphrasing and rewriting functionality, particularly in the prosumer and knowledge-worker segment.
- Ginger Software: Ginger offers grammar checking, sentence rephrasing, and translation tools via browser extensions and desktop apps. Historically a direct competitor to LanguageTool in the grammar/spell-checking category before being acquired by AI21 Labs.
- Hemingway Editor: Hemingway Editor focuses on style and readability improvement (sentence complexity, adverb use, passive voice), overlapping with LanguageTool's style-analysis and Picky Mode features. Comparable target user: writers, professionals, and students refining prose.
Broad incumbents
- Microsoft Editor: Microsoft Editor is a free/bundled grammar and writing assistant built into Microsoft 365 (Word, Outlook) and available via browser extension. It competes with LanguageTool primarily through default availability within the Microsoft productivity ecosystem, capturing users who do not seek a separate tool.
- Google (Workspace spelling/grammar suggestions): Google Docs provides built-in grammar and spelling suggestions as part of Workspace, competing with LanguageTool via default availability and seamless integration. As a broad incumbent, Google is the dominant productivity provider and a key structural competitor for free-tier users.
Emerging players
- Sapling.ai: Sapling offers AI-powered grammar, autocomplete, and writing assistance primarily targeting customer support and enterprise messaging. It overlaps with LanguageTool on the API/enterprise side, providing a comparable B2B API product for developers integrating writing assistance into workflows.
- Trinka AI: Trinka is an AI grammar checker focused on academic, technical, and formal writing. It overlaps with LanguageTool's academic and professional-writer segments and represents an emerging specialist competitor in the formal/academic writing niche.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key risks6 records
Key highlights7 records
Customer concentration
LanguageTool social profiles
Digital presenceLanguageTool compliance and trust
Trust signalCompliance1 record
LanguageTool financial estimates
Financial estimateRevenue estimate
Valuation estimate
LanguageTool leadership team
Management profileNumber of profiles
Profiles2 records
LanguageTool funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
LanguageTool M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about LanguageTool
What does LanguageTool do?
LanguageTool provides an AI-based grammar, spelling, punctuation, and style checker that operates across 30+ languages, available as a free web editor and via Premium subscriptions. The company complements the core checker with an AI-powered paraphrasing tool, a proofreading HTTP API for developers, and a dedicated GDPR-compliant Business tier for organizations. The underlying grammar engine is open-source (Apache 2.0) and is distributed via browser extensions, desktop apps, mobile apps, and office/email integrations.
Is LanguageTool a public or private company?
LanguageTool is a private company. It is classified as corporate owned and is currently operating.
When was LanguageTool founded?
LanguageTool was founded in 2003. It employs 11 to 50 people.
Where is LanguageTool based?
LanguageTool is headquartered in Potsdam, Germany, in the Europe region.
How does LanguageTool make money?
Four revenue lines are on record. Premium Individual Subscription is the primary driver. The others are premium Teams Subscription, proofreading API and enterprise/Business Solutions.
Who are LanguageTool's main competitors?
Direct peers on record are Grammarly, QuillBot, ProWritingAid, Wordtune, Ginger Software and Hemingway Editor. Broad incumbents are Microsoft Editor and Google (Workspace spelling/grammar suggestions). Emerging players are Sapling.ai and Trinka AI.
Does LanguageTool have an API?
Yes. LanguageTool offers an HTTP API that allows developers to integrate grammar and spell checking into their own applications. The API supports running a self-hosted LanguageTool server locally or in the cloud. Public server access via HTTP is also available for developers to use. Developer documentation is at languagetool.org/http-api.
What industry is LanguageTool in?
LanguageTool's product category is Writing Assistance Software. Its primary akta.pro industry code is HDAAADAG, Content Generation & Writing Assistance (copy, emails, reports). Its NAICS code is 541511 and its SIC code is 7372.