Best Free Grammar Checkers for 2026: Typlx, Grammarly, LanguageTool Compared
June 27, 2026
Whether you're writing emails, blog posts, or academic papers, a good grammar checker can save you from embarrassing mistakes and help you communicate more clearly. But with so many options available in 2026, how do you choose the right one? We've compared the top free grammar checkers — including Typlx, Grammarly, LanguageTool, Harper, and Hemingway Editor — to help you find the best fit for your needs, budget, and privacy expectations.
What Makes a Great Grammar Checker?
Before diving into individual tools, here are the criteria we used to evaluate each one:
- Accuracy — How well does it catch real errors without flooding you with false positives?
- Privacy — Does your text stay on your device, or is it sent to external servers for processing?
- Platform support — Is it available as a browser extension, desktop app, or mobile keyboard?
- Cost — What do you get for free, and what's locked behind a paywall?
- Ease of use — Can you install it and start writing immediately, or does it require setup and account creation?
1. Typlx — Best for Privacy and Open-Source Users
Typlx is a free, open-source grammar checker that runs an LLM directly on your device. Unlike most competitors, it never sends your text to a cloud server — everything is processed locally using a compact language model optimized for grammar correction.
- Platform: Chrome extension, Android keyboard, iOS keyboard
- Cost: Free (open-source, MIT license)
- Processing: 100% local — on-device LLM
What sets Typlx apart
- No account required — install and start using immediately
- No data leaves your device, ever
- LLM-powered suggestions that understand context, not just rules
- Fully open-source — inspect, modify, and contribute to the code on GitHub
- Works offline once the model is downloaded
- Lightweight and fast, even on modest hardware
Best for: Privacy-conscious users, developers, open-source advocates, and anyone who wants powerful grammar checking without giving up their data.
Install the Typlx Chrome Extension — Free →
2. Grammarly — Best for Breadth of Features
Grammarly is the most widely known grammar checker, offering a comprehensive suite of writing tools powered by cloud-based AI. Its free tier covers basic grammar and spelling, while premium plans add tone detection, clarity suggestions, plagiarism checking, and generative AI features.
- Platform: Chrome extension, desktop apps (Windows/Mac), mobile keyboards, web editor
- Cost: Free tier (limited); Premium starts at ~$12/month
- Processing: Cloud-based
What sets Grammarly apart
- Largest feature set of any grammar checker
- Tone and clarity detection beyond basic grammar
- Generative AI writing assistant (GrammarlyGO)
- Integrations with Microsoft Office, Google Docs, and more
- Team and enterprise plans for organizations
Best for: Users who want the most features in one tool and don't mind cloud processing or creating an account.
3. LanguageTool — Best for Multiple Languages
LanguageTool is an open-source, rule-based grammar checker that supports over 30 languages. It's a strong choice for multilingual writers, and its core engine is available under an open-source license. The hosted version adds premium features like a personal dictionary and style suggestions.
- Platform: Chrome/Firefox extensions, desktop apps, web editor, LibreOffice/Word add-ons
- Cost: Free tier (limited checks); Premium starts at ~$5/month
- Processing: Cloud-based by default; self-hosted option available
What sets LanguageTool apart
- Supports 30+ languages out of the box
- Open-source core engine (LGPL license)
- Self-hosted option for privacy-conscious users
- Strong rule-based checks with low false-positive rates
- Active community contributing language rules
Best for: Multilingual writers, non-English speakers, and users who want a self-hosted option with broad language coverage.
4. Harper — Best Lightweight Open-Source Option
Harper is a lightweight, rule-based grammar checker designed for developers and technical writers. Written in Rust, it's extremely fast and runs entirely on your device. It focuses on catching common English mistakes without the overhead of an LLM or cloud connection.
- Platform: CLI, Neovim/VS Code integrations
- Cost: Free (open-source, Apache 2.0 license)
- Processing: 100% local
What sets Harper apart
- Blazing fast — written in Rust for maximum performance
- Designed for Markdown, code comments, and technical writing
- Zero dependencies and minimal resource usage
- Deep editor integrations for developers
- No browser extension — focused on code editors
Best for: Developers and technical writers who want a fast, no-frills grammar checker integrated into their code editor.
5. Hemingway Editor — Best for Readability
Hemingway Editor takes a different approach. Rather than just catching grammar errors, it focuses on making your writing clearer and more readable. It highlights complex sentences, passive voice, adverb overuse, and readability grade level. It's more of a style tool than a traditional grammar checker.
- Platform: Web editor, desktop apps (Windows/Mac)
- Cost: Free (web editor); Desktop app ~$20 one-time purchase
- Processing: Local (desktop app); browser-based (web editor)
What sets Hemingway apart
- Readability scoring and grade-level analysis
- Highlights passive voice, complex sentences, and adverb overuse
- Clean, distraction-free writing interface
- One-time purchase for the desktop app — no subscription
- Ideal for blog posts, articles, and public-facing content
Best for: Content writers and bloggers who want to improve clarity and readability, not just grammar.
Side-by-Side Comparison
| Feature | Typlx | Grammarly | LanguageTool | Harper |
|---|---|---|---|---|
| Free tier | ✅ Full core | ✅ Limited | ✅ Limited | ✅ Full |
| Local processing | ✅ Yes | ❌ Cloud | ❌ Cloud default | ✅ Yes |
| Open-source | ✅ Yes | ❌ No | ✅ Core engine | ✅ Yes |
| LLM-powered | ✅ Yes | ✅ Cloud LLM | ❌ Rule-based | ❌ Rule-based |
| Chrome extension | ✅ | ✅ | ✅ | ❌ |
| Mobile support | ✅ Android/iOS | ✅ | ✅ | ❌ |
| Multilingual | English (more planned) | English primary | 30+ languages | Limited |
| No account required | ✅ | ❌ | ❌ | ✅ |
The Privacy Question: Why It Matters in 2026
In an era of increasing data breaches, surveillance, and AI training on user data, where your text gets processed matters more than ever. Most grammar checkers send every keystroke to a cloud server, where your writing may be stored, analyzed, or used to train AI models.
This raises real concerns, especially for:
- Business professionals — Confidential emails, contracts, and internal documents could be exposed
- Students and academics — Research papers and thesis drafts may be stored by third parties
- Journalists and activists — Sensitive communications could be intercepted or logged
- Healthcare and legal workers — HIPAA, GDPR, and other regulations may prohibit sending patient or client data to cloud services
Tools like Typlx and Harper solve this by processing everything locally. Your text never leaves your device, and there's no server to breach. For a deeper dive into this topic, read our guide on privacy-focused writing tools.
Who Should Use Which Tool?
Choose Typlx if:
- Privacy is your top priority
- You want LLM-powered suggestions without cloud processing
- You prefer open-source software you can inspect and contribute to
- You don't want to create an account or pay for a subscription
- You need a grammar checker that works on Chrome, Android, and iOS
Choose Grammarly if:
- You want the widest range of writing features in one tool
- You need tone detection, plagiarism checking, or AI writing assistance
- You work in a team environment that uses Grammarly Business
- Cloud processing and account creation are acceptable tradeoffs for you
Choose LanguageTool if:
- You write in multiple languages
- You need grammar checking beyond English
- You want the option to self-host for privacy
- You use LibreOffice or other open-source office tools
Bottom Line
There's no single "best" grammar checker — the right choice depends on what you value most. If you want the most features, Grammarly is hard to beat. If you need multilingual support, LanguageTool is the clear winner. If you're a developer who lives in a code editor, Harper is worth a look.
But if you want a grammar checker that's free, private, open-source, and powered by a local LLM, Typlx is the best option available in 2026. It proves that you don't have to sacrifice your privacy to get intelligent grammar suggestions.
Install the Typlx Chrome Extension — Free →
Typlx is available as a Chrome extension and Android/iOS mobile keyboard. The core tool is free and open-source.
Last updated: June 2026