Private Grammar Checker - Harper
Extension Actions
- Extension status: Featured
The private grammar checker for 21st Century English
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. That's the power of open source.
Latest reviews
- Maryellen Williams
- It's helping me catch mistakes I wouldn't have noticed right away. When I looked at some of the flags and thought they were wrong i just looked for a different word or read the sentence out and realized where I went wrong. For my needs it's great. It does have some bugs, but I'm expecting they will eventually get worked out. Like some of the capitalization flags.
- Mar Belle
- I really wanted to like this and escape Grammarly but unfortunately it doesn't seem up to the task, missing many grammar errors that Grammarly picks up and most annoyingly, given that I do most of my writing within the Wordpress editor, marking any sententence which contains a link as an uncapitalised sentence error proceeding and following the link. I might check it out again in the future but as is, Harper feels not at all production ready for what is a very common writing case.
- Rogerio Taques
- I've been using Harper instead of Grammarly for a few months already, and I can't be happier! I can't wait to see the great improvement when this tool reaches version 1.0.0! Great job! I hope that, eventually, it will also support languages other than English.
- Gustavo Azevedo
- Local. Privacy focused.
- Lukas Werner
- Best free grammar checker that I've ever used! Also big plus that it all stays local.
- Luke Sanabria
- I finally got a big enough ick using Language Tool given the widely-understood security and privacy concerns that I picked my head up to find something else. I am absolutely over the moon with what Harper provides. Slots in like a charm and works in the exact way I used LT, minus the shady key-logging and targeting potential. Thank you so much for building this!!
- Steven Hubert
- Doesn't work with any MSFT product, Excel, Outlook, etc.. Basically anywhere you would actually need to use it.
- Martin Caminoa Lizarralde
- Harper related files in TypeScript are requested regardless if I disable it on a specific website. Missing many rules, e.g. misuse of verb tenses e.g. use of relating or related does not make a difference in a sentence, misuse or overusing of pronouns, it's good to detect some typos though. Also it misses an editor for cases on which the extension doesn't work in an input field.
- Daniel
- Does not work in Google Documents, but LanguageTool does it
- imbolc
- I've been using Harper in Neovim for a long time and am glad to see it as an extension!
- Filip Cujanovic
- Awesome extension! It's privacy focused, that means that every check it done locally on your computer, there is no server where your data goes! And because of that it's blazingly fast compared to Grammarly.
- Notname Notname
- Harper is the privacy-focused grammar checker the world needs! I've been incredibly frustrated with overbearing suggestions from alternatives like Grammarly and concerned about their privacy policy. I've been using Harper on my notes in Obsidian for months, and it's been a game-changer! I'm so happy that it's available for the browser!
- Justin Liu
- It works great!