Fast, private developer tools
DevToolsBox is a small set of everyday developer tools. Every one of them runs entirely in your browser: nothing you paste is uploaded, stored or logged. No sign-up, no limits.
Tools
- JSON FormatterFormat, validate and minify JSON directly in your browser.
- JSON DiffCompare two JSON documents structurally and see exactly what changed.
- Text DiffCompare two texts and highlight what was added and removed.
- JWT DecoderDecode and inspect a JSON Web Token without sending it anywhere.
- Base64 Encoder / DecoderEncode and decode Base64, with full Unicode and URL-safe support.
Why everything runs locally
Developer tools routinely handle sensitive material: access tokens, API responses, configuration files, customer records pasted in to debug a bug report. Sending that to someone else’s server to be formatted is an unnecessary risk.
None of these tools need a server, so none of them have one. The page loads once, and every conversion happens on your machine — which also makes them fast and usable offline once cached.