What is Harper?
Grammar and spelling checker that runs on your device in browsers, code editors and macOS apps.
Who is Harper best for?
Harper is best for writers and developers who want English grammar checks that never send their text to a server.
Private writing
Every check runs on your device with no cloud round trip, telemetry or language model.
Developers in code editors
The harper-ls language server checks comments and Markdown in VS Code, Neovim, Zed, Helix, Emacs and Sublime Text.
Obsidian and WordPress writers
Official plugins underline mistakes inside an Obsidian vault and the WordPress block editor.
Mac users
Harper Desktop checks text in any macOS text field, from Mail to Slack.
How much does Harper cost?
Harper is free in every form, from the browser extensions to Harper Desktop and the editor plugins, with Apache 2.0 code and no paid plan.
- Browser extensions, Harper Desktop and editor plugins
- No account, telemetry or cloud checks
- English only
Harper has no paid plan or hosted service. Harper Desktop for macOS is in beta. Developers can also use the harper-ls language server, the harper.js library or the harper-core Rust crate. Full pricing on github.com. We checked these prices on .
How do readers rate Harper?
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Is Harper open source?
Yes. Harper's code is public under the Apache 2.0 licence, so you can run it on your own server.
On GitHub
17,641stars
+1,236 (+7.5%) in the last 30 days
- Last commit
- 13 Nov
- Repository age
- 3 years
- Latest release
- 6 Nov
- Licence
- Apache 2.0
- Self-hosted
- Yes
- Repository
- Automattic/harper
What are the best Harper alternatives?
Harper is an open source alternative to Grammar Check, Grammarly, Manzoni and LanguageTool.
Questions about Harper
What is Harper?
Grammar and spelling checker that runs on your device in browsers, code editors and macOS apps.
Who is Harper for?
Harper is best for writers and developers who want English grammar checks that never send their text to a server.
Is Harper free?
Yes. Harper has a free Free download plan: browser extensions, Harper Desktop and editor plugins.
Is Harper open source?
Yes. Harper's code is public under the Apache 2.0 licence, so you can run it on your own server.
What are the best Harper alternatives?
The closest alternatives on Recaply are Grammar Check, Grammarly, Manzoni and LanguageTool.
Where can I try Harper?
On its official website, writewithharper.com.
Does Harper use AI?
No. Harper is a rule-based checker that runs on your device with no language model in the loop, so suggestions arrive in under 10 ms and your writing is never used to train a model.
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