Offline, privacy-first grammar checker. Fast, open-source, Rust-powered.
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.
This snap bundles the harper-ls Language Server and experimental harper-cli
tool.
If you store documents on an external USB drive or similar, ensure you
manually connect the removable-media interface after installing the snap:
snap connect harper:removable-media