Grammarly vs LanguageTool

Overview

AI-powered writing assistant that checks grammar, spelling, style, and tone. Used by 30 million people daily. is a popular proprietary tool in the productivity space. LanguageTool is a free, open-source alternative that gives organizations complete control over their data and deployment.

Key Differences

• Cost: Grammarly costs Free / $12–$15/month per user; LanguageTool is Free (self-hosted)
• License: Grammarly is Proprietary; LanguageTool is licensed under LGPL 2.1
• Data ownership: LanguageTool can be self-hosted, meaning your data stays on infrastructure you control
• Vendor lock-in: LanguageTool eliminates dependency on a single commercial vendor
• Community: LanguageTool has an active open-source community contributing features and fixes

Pricing Comparison

Pros and Cons

Grammarly

Pros:

• Polished, professionally designed user interface
• Large ecosystem of official integrations
• Managed infrastructure — no server maintenance required
• Enterprise SLA and dedicated support available
• Mobile apps are well-maintained and reliable

Cons:

• Significant per-user monthly cost that scales linearly with team size
• Your data is stored on the vendor's infrastructure
• No ability to inspect or modify the source code
• Feature roadmap controlled entirely by the vendor
• Risk of pricing changes, acquisition, or discontinuation

LanguageTool

Pros:

• Free to self-host — costs only server infrastructure
• Complete data ownership and privacy control
• Source code is auditable and modifiable
• Active open-source community
• No vendor lock-in or risk of sudden pricing changes

📦 GitHub: languagetool-org/languagetool · ⭐ ~12k stars

Cons:

• Requires technical knowledge to self-host and maintain
• May lack some advanced features found in the proprietary version
• Support relies on community forums rather than a paid helpdesk
• UI polish may lag behind the proprietary tool
• You are responsible for updates, backups, and security patches

When to Choose Each

Choose Grammarly if: Grammarly is the right choice when you need the most polished user experience, the broadest integration ecosystem, and professional support with SLA guarantees.

Choose LanguageTool if: LanguageTool is ideal for privacy-conscious teams, organizations with strict data sovereignty requirements, or anyone wanting to eliminate per-seat subscription costs at scale.

Migration Path

Export your data from Grammarly in its standard export format, review LanguageTool's import documentation, and plan for a pilot period where both tools run in parallel.

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