Merge JSON

What is Merge JSON?

Merge JSON is a free developer toolkit with 50+ JSON utilities. Merge multiple JSON files, validate syntax, prettify, minify, compare, convert, flatten, escape, and transform JSON instantly. Everything runs locally in your browser, so your data never leaves your device. No signup, no uploads, and no server processing—fast, secure, and privacy-first tools for developers, data engineers, and API teams.