The biggest complaint about Harper is that the quality of grammar checking still needs some work. I've got an exciting new project I'm preparing to discuss later this week (hopefully) in that area. It should be a step-function improvement over our previous methods for creating new rules.
In the meantime, I've collected some recent sightings of Harper in the wild:
Published August 12, 2025 at 6:00 AM
Proofread by Harper.
I like HackerNews, but I don't love that so much of it has turned into discussion of a single topic: AI. This is a version of HackerNews, filtered to remove any article focusing on __AI__. Refreshes about every ten minutes.
It didn't work for me, and if you reading this, it probably won't work for you either.
Back in my day, we used math for autocomplete.