Offline, privacy-first grammar checker. Fast, open-source, Rust-powered
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Andrew Dunbar 387f5e2746
feat: passerbys→passersby (#2135)
Co-authored-by: Elijah Potter <me@elijahpotter.dev>
2025-11-04 19:48:45 +00:00
.github fix(ci): don't build all VS Code plugins on PRs 2025-10-27 09:48:54 -06:00
.vscode chore: mostly annotating verbs and nouns (#1874) 2025-09-08 12:20:49 +00:00
harper-brill Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-cli build(deps): bump clap from 4.5.50 to 4.5.51 (#2127) 2025-11-03 18:39:11 +00:00
harper-comments feat: sync language support (#2123) 2025-11-03 19:46:57 +00:00
harper-core feat: passerbys→passersby (#2135) 2025-11-04 19:48:45 +00:00
harper-html Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-ink Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-jjdescription Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-literate-haskell Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-ls feat: sync language support (#2123) 2025-11-03 19:46:57 +00:00
harper-pos-utils feat(core): upgrade to Burn v0.19.0 2025-10-29 16:28:13 -06:00
harper-python Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-stats Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-tree-sitter Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-typst Release 0.70.0 2025-10-24 14:48:49 -06:00
harper-wasm build(deps): bump getrandom from 0.3.3 to 0.3.4 (#2113) 2025-10-27 14:47:15 +00:00
packages feat(chrome-ext): enable for Google Classroom 2025-11-04 08:11:06 -07:00
.dockerignore fix: dockerfile issues 2025-03-19 11:51:08 +08:00
.editorconfig feat: enforce LF line endings everywhere 2025-03-10 10:51:39 -06:00
.envrc feat(devshell): init devshell 2025-04-04 16:06:31 -04:00
.gitattributes feat: enforce LF line endings everywhere 2025-03-10 10:51:39 -06:00
.gitignore refactor(web): build out feedback mechanisms (#2069) 2025-10-22 11:37:49 -06:00
.node-version chore(node): use lts/* instead of lts/iron 2025-02-03 16:54:14 +08:00
.npmrc fix: dockerfile issues 2025-03-19 11:51:08 +08:00
ARCHITECTURE.md docs: moved architecture document to the web 2024-12-27 12:03:11 -07:00
biome.json refactor(web): build out feedback mechanisms (#2069) 2025-10-22 11:37:49 -06:00
Cargo.lock build(deps): bump clap from 4.5.50 to 4.5.51 (#2127) 2025-11-03 18:39:11 +00:00
Cargo.toml feat(core): opt-level = 3 results in faster tests 2025-10-29 15:16:09 -06:00
COMPARISON.md fix: changed links from elijah-potter/harper to automattic/harper 2024-12-18 08:05:16 -07:00
CONTRIBUTING.md docs: moved contributor documentation to the web 2024-12-27 11:49:08 -07:00
demo.md feat(web): make demo more enticing 2025-09-24 08:09:14 -06:00
docker-compose.dev.yml refactor(web): build out feedback mechanisms (#2069) 2025-10-22 11:37:49 -06:00
docker-compose.yml refactor(web): build out feedback mechanisms (#2069) 2025-10-22 11:37:49 -06:00
Dockerfile build(deps): bump getrandom from 0.3.3 to 0.3.4 (#2113) 2025-10-27 14:47:15 +00:00
flake.lock Add wasm-bindgen-cli to nix flake (#2108) 2025-10-27 15:49:28 +00:00
flake.nix Add wasm-bindgen-cli to nix flake (#2108) 2025-10-27 15:49:28 +00:00
justfile build(deps): bump getrandom from 0.3.3 to 0.3.4 (#2113) 2025-10-27 14:47:15 +00:00
LICENSE fix: filled in LICENSE 2024-03-25 14:58:52 -06:00
logo.svg feat: added logo to README.md and web client 2024-02-15 20:56:27 -07:00
package.json feat(chrome-ext): add double-shift hotkey (#1574) 2025-07-21 14:49:11 -06:00
pnpm-lock.yaml refactor(web): build out feedback mechanisms (#2069) 2025-10-22 11:37:49 -06:00
pnpm-workspace.yaml fix: dockerfile issues 2025-03-19 11:51:08 +08:00
README.md feat: add download badges 2025-10-07 11:23:26 -06:00
rust-toolchain.toml feat: enforce stable rust with a rust-toolchain.toml 2024-09-27 08:28:57 +02:00
rustfmt.toml feat(core): added Whereas rule 2025-02-06 08:57:02 -07:00

Harper

Harper Binaries Website Checks Crates.io NPM Version Downloads Obsidian Plugin Downloads

Harper is an English grammar checker designed to be just right. I created it after years of dealing with the shortcomings of the competition.

Grammarly was too expensive and too overbearing. Its suggestions lacked context, and were often just plain wrong. Not to mention: it's a privacy nightmare. Everything you write with Grammarly is sent to their servers. Their privacy policy claims they don't sell the data, but that doesn't mean they don't use it to train large language models and god knows what else. Not only that, but the round-trip-time of the network request makes revising your work all the more tedious.

LanguageTool is great, if you have gigabytes of RAM to spare and are willing to download the ~16GB n-gram dataset. Besides the memory requirements, I found LanguageTool too slow: it would take several seconds to lint even a moderate-size document.

That's why I created Harper: it is the grammar checker that fits my needs. Not only does it take milliseconds to lint a document, take less than 1/50th of LanguageTool's memory footprint, but it is also completely private.

Harper is even small enough to load via WebAssembly.

Language Support

Harper currently only supports English, but the core is extensible to support other languages, so we welcome contributions that allow for other language support.

Performance Issues

We consider long lint times bugs. If you encounter any significant performance issues, please create an issue on the topic.

If you find a fix to any performance issue, we would appreciate the contribution. Just please make sure to read our contribution guidelines first.

Huge Thanks

This project would not be possible without the hard work from those who contribute.

Harper's logo was designed by Lukas Werner.