Style and Grammar Checker for 25+ Languages
↑ +4 today
Open Source Alternative Guide
Best Open Source Alternatives to Grammarly
Looking for a free, self-hosted, and privacy-first replacement for Grammarly? These community-verified open source projects replace ai writing assistant & grammar checker without recurring per-seat fees or cloud vendor lock-in.
Proprietary Pricing:
$12–$15/month per user
Open Source Cost:
$0 (Self-Hosted)
Tracked Stars:
★ 58.2K
Alternative Projects:
16 verified repos
Why Engineering Teams Are Replacing Grammarly
✓ Zero Subscription Invoices
Deploy across 5 or 5,000 developers with zero incremental per-seat charges or usage surcharges.
✓ Full Data Sovereignty
No third-party cloud data scanning, closed training, or overseas data transfer compliance risks.
✓ Code Ownership
Inspect the architecture, add internal integrations, build custom plugins, and never worry about discontinued features.
Top Rated Grammarly Alternatives (16)
Ranked by verified GitHub stars & growth
Offline, privacy-first grammar checker. Fast, open-source, Rust-powered
↑ +16 today
基于 Claude Code 的长篇网文辅助创作系统，解决 AI 写作中的「遗忘」和「幻觉」问题，支持 200 万字量级 连载创作。
↑ +1 today
Skill that audits and rewrites content to remove AI writing patterns. Use it with your favorite agents including Claude Code, OpenClaw, Codex, and Hermes.
↑ +24 today
开箱即用的AI标书编写工具，标书AI生成工具，投标工具箱、知识库、标书查重、废标项检查，完全开源免费，欢迎使用
↑ +19 today
SPONSORED
Featured Developer Tools & Services
De-AI writing skill for any Agent Skills-compatible agent (77+ via the Skills CLI), with native plugins for Claude Code, Codex, Grok Build, and Antigravity. Narrative-architecture repair for fiction, venue-matched rules for professional prose. Based on StoryScope (arXiv:2604.03136).
↑ +14 today
说人话｜中文优先的去 AI 味改写 skill：保事实、分场景、改完可直接发。Chinese-first rewrite skill for Codex / Claude Code / Cursor / ChatGPT — removes AI tone, preserves facts.
↑ +1 today
AI 小说创作软件：把灵感、角色、世界观、大纲、章节写作、审稿和修稿组织成可控流程；提供 Windows/macOS 桌面版，支持本地和在线模型。AI Novel Writing Software: Organizes inspirations, characters, worldbuilding, outlines, chapter drafting, review, and revision into a controllable workflow. Features desktop apps for Windows/macOS, Ollama integration, and a DeepSeek Harness (DSH) plugin preview.
↑ +83 today
LeanType is an Open-source keyboard, fork of HeliBoard with additional features and customisation
↑ +2 today
「說人話」：繁體中文的去 AI 味改寫 skill。抓 38 種 AI 寫作痕跡，順手校正中國用語與半形標點，給 Claude Code / Codex / Cursor 用。
↑ +1 today
AI生成の日本語を自然な日本語へ推敲するAgent Skill / Agent Skill for Refining AI-Generated Japanese into Natural Japanese
↑ +47 today
易创：纯本地、开源的 AI 网文写作桌面软件，支持小说创作、AI 辅助写作、BYOK 与自定义提示词。
↑ +11 today
AI-powered IDE for novel writing — local LLM + RAG, privacy-first, BYOK. For web fiction authors and creative writers.
↑ +1 today
AI-writing humanizer for KO/EN/ZH/JA
↑ +2 today
Not Ai isn’t just about bypassing AI detectors. It puts good writing first, creating clear, honest prose shaped by human writing standards. It’s perfect for college and school projects, LinkedIn/X posts, emails, factual articles, personal essays, social media posts, and technical documentation, especially GitHub READMEs
↑ +9 today
A humanizer for work writing: takes the AI tone out without changing what your text says or commits to. Agent Skill + evidence: blind judges, hand-checked meaning changes, Pangram.
↑ +1 today
⚖️ Head-to-Head Grammarly Alternative Comparisons
Compare the top Grammarly replacements side by side on stars, momentum, and architecture.
languagetool vs harper
★ 15.1K vs ★ 16.3K
Compare side-by-side →
languagetool vs webnovel-writer
★ 15.1K vs ★ 7.5K
Compare side-by-side →
languagetool vs avoid-ai-writing
★ 15.1K vs ★ 4.8K
Compare side-by-side →
harper vs webnovel-writer
★ 16.3K vs ★ 7.5K
Compare side-by-side →
harper vs avoid-ai-writing
★ 16.3K vs ★ 4.8K
Compare side-by-side →
webnovel-writer vs avoid-ai-writing
★ 7.5K vs ★ 4.8K
Compare side-by-side →
Frequently Asked Questions
What is the most popular open source alternative to Grammarly?
The leading open source project in this space is languagetool-org/languagetool with over 15,107 GitHub stars. It provides active developer community support, extensive documentation, and transparent licensing.
Are these open source alternatives free to use in commercial teams?
Yes. The vast majority of these repositories are licensed under permissive open-source licenses such as MIT, Apache 2.0, or AGPL, allowing developers to deploy and self-host them within commercial companies with zero subscription costs.
How do I deploy and self-host these alternatives?
Most top alternatives provide pre-built Docker containers and Docker Compose templates, enabling 1-command deployment onto a private VPS (Hostinger, DigitalOcean, Hetzner) or enterprise Kubernetes clusters.
From our network