Who built this
Hi, I'm Son Nguyen, a Vietnamese software developer. I built jsonsql.dev because I was tired of existing online JSON tools. Most of them are slow, covered in ads, or — worst of all — upload your data to their servers without telling you.
I wanted something better: fast tools that respect your privacy and just work. So I built 19 of them, all running 100% in your browser. No server processing, no data uploads, no accounts, no tracking.
Why this site exists
Every tool on jsonsql.dev processes data entirely in JavaScript on your machine. You can verify this yourself — open DevTools, check the Network tab, and you'll see zero data leaving your browser. This isn't a marketing claim; it's how the code works.
The flagship tool is JSON Query — the only online tool that combines JSONPath, SQL, and MongoDB query syntax in a single interface. No other site does this.
The tools
jsonsql.dev offers 19 free browser-based tools: JSON formatter, validator, viewer, diff, schema generator, query engine (SQL + JSONPath + MongoDB), converters (CSV, YAML, SQL), JWT decoder, Base64, URL encoder, hash generator, UUID generator, and regex tester. All free, no limits, works offline once loaded.
Contact
Found a bug or have a suggestion? Reach out via GitHub.