Developer tools that respect your data.

Every tool here runs entirely in your browser. Nothing is uploaded, nothing is logged, nothing is stored. Paste something, get an answer, close the tab.

{ }

JSON Formatter & Beautifier

Format, beautify and pretty-print JSON

1 ✓

JSON Validator

Check if JSON is valid

2 64

Base64 Encoder / Decoder

Encode or decode Base64

3 t↔d

Unix Timestamp Converter

Convert unix time to date and back

4 id

UUID Generator (v4)

Generate random UUID v4 values

5 jwt

JWT Decoder

Decode JWT header and payload

6 sql

SQL Formatter

Format and beautify SQL queries

7 ▤

JSON Viewer

Explore JSON in a collapsible tree

Why DevFormat

Private by design.Every tool runs client-side. What you paste never touches a server, ours or anyone else's.

Errors you can act on.The JSON tools point to the exact line and column, plus a plain-English reason — not a stack trace.

Free, fast, no account.Nothing to sign up for. Hit ⌘K, pick a tool, get on with your day.