3 Best Open-Source Alternatives to Grammarly (2026)

Last checked October 2026 · 8 alternatives to Grammarly in our catalog

Grammarly paid plans start at $12/mo, which is why people look for an open-source alternative. Below are 3 open-source options you can inspect, modify and often self-host - 2 are completely free, 1 runs on Linux and 2 work in the browser.

Quick picks

No paid tier at all

Cognee

Runs on Linux

yazi

Picked from listing data (price model, license, platforms, community votes), not hands-on testing.

Grammarly alternatives compared

Alternative	Price	Open source	Platforms	What it is
Cognee	Free	Yes (Apache-2.0)	Web	Open‑source memory engine that lets LLM agents remember across sessions
yazi	Free	Yes (MIT)	Windows, Mac, Linux	Fast async terminal file manager written in Rust
planka	Freemium	Yes (Other)	Web	Open-source Kanban board with real‑time sync and markdown cards

Cognee

FreeOpen source · Apache-2.0Web

Open‑source memory engine that lets LLM agents remember across sessions

Open‑source and free to use
Flexible deployment (self‑hosted or cloud)
Multi‑modal retrieval (graph, vector, relational)

Limited official commercial support
Requires technical knowledge to self‑host

Full details Grammarly vs Cognee

yazi

FreeOpen source · MITWindowsMacLinux

Fast async terminal file manager written in Rust

Lightning‑fast async performance
Rich image and code previews
Highly extensible via Lua plugins

Steep learning curve for new terminal users
Limited graphical UI for non‑CLI users

Full details Grammarly vs yazi

planka

FreemiumOpen source · OtherWeb

Open-source Kanban board with real‑time sync and markdown cards

Free plan includes: Unlimited boards & cards · Real‑time synchronization · All core features · Self‑hosted for free

Open-source and free to self‑host
Real‑time synchronization across users
Rich Markdown support for detailed cards

Self‑hosting requires Docker knowledge
Limited native reporting features

Full details Grammarly vs planka

Frequently asked questions

What is the best free alternative to Grammarly?

Cognee is the first free alternative we list for Grammarly and has no paid tier. Others worth a look: yazi and planka. Which one fits depends on what you use Grammarly for, so check the platform and free-plan details for each.

Is there an open-source alternative to Grammarly?

Yes: Cognee, yazi and planka. Open-source options can usually be inspected, modified and self-hosted.

Does Grammarly have a free plan?

Yes. The free plan includes Grammar & spelling checks, Tone detection and Browser extension. Paid plans start at $12/mo.

How this list is built: alternatives come from our catalog's curated alternative relationships; price model, license and platforms come from each product's listing; order is fully-free first, then community votes.