Show HN: A Simple, Ad-Free, Privacy-Respecting JSON Linter

I built this JSON linter because, while there are plenty of great ones out there, I wanted something that fits my needs—ad-free, no tracking, privacy-focused, and lightweight. What started as a quick “1-hour project” quickly spiraled into a more "complex" challenge.

Initially, I used a simple <textarea>. It was easy, fast, and functional, but I wanted code highlighting for better readability. That’s when things got tricky. Implementing syntax highlighting meant moving to a <div> with contenteditable. While it works, it introduced issues like cursor jumping during formatting—one of those things that seems simple but can be maddening in practice.

Looking back, the better approach would’ve been to stick with a <textarea> for editing and use a separate <div> for displaying formatted, syntax-highlighted JSON. Lesson learned.

Right now, it works (though it’s not perfect), and I’m sure there are some rough edges in the editing experience. Still, it "works" and I plan to keep improving it over time. My next planned feature is adding JSON Query functionality, which should make it more versatile.

Honestly, I’m probably posting this just to hear comments like, “What’s the most useless thing you’ve ever built?” But hey, if you try it out, break it, or even like it, let me know!