All Developer Tools
Fast, free, browser-based utilities for everyday developer tasks. Everything runs locally — your data never leaves your device.
JSON Formatter
Format, beautify, and minify your JSON data. Powered by Monaco Editor for a VS Code-like editing experience.
JSON Validator
Validate JSON syntax and catch errors like trailing commas, missing quotes, and unescaped characters.
JSON ↔ YAML Converter
Convert JSON to YAML or YAML to JSON instantly in your browser. Supports nested structures, arrays, and comments.
JSON ↔ XML Converter
Convert JSON to XML or XML to JSON instantly in your browser. Supports tag attributes, arrays, and CDATA blocks.
JSON ↔ CSV Converter
Convert JSON to CSV or CSV to JSON instantly in your browser. Supports custom delimiters, headers, and local file upload.
JWT Decoder
Decode JWT tokens locally in your browser. Inspect the Header, Payload, and Signature without sending tokens to a server.
Base64 Converter
Encode text or images to Base64, or decode Base64 strings back to plain text and Data URLs.
UUID Generator
Generate cryptographically secure UUID v4 identifiers in bulk using your browser's native Web Crypto API.
Timestamp Converter
Convert Unix epoch timestamps to human-readable dates, or pick a date to get its Unix timestamp in seconds and milliseconds.
Regex Tester
Test regular expressions with live match highlighting, flag toggles, and replace testing using JavaScript's native RegExp engine.
URL Encoder / Decoder
Encode URLs for safe transmission or decode percent-encoded strings. Supports both full URI and URI component encoding.
Hash Generator
Generate SHA-256, SHA-512, MD5, SHA-384, and SHA-1 cryptographic hashes instantly in your browser. 100% private.
Why Use DevToolkit?
All tools run entirely in your browser using native JavaScript and Web APIs. There are no server round-trips, no accounts, no paywalls, and no data stored. Each tool is built to solve one problem well — fast, private, and always available.
A practical workflow for common developer tasks
Start with the tool that matches the format you are working with, then use the related guides to understand the result. For example, validate JSON before converting it, decode a JWT only to inspect its contents, and use the timestamp converter to check whether an API value is expressed in seconds or milliseconds.
Inspect
Format, decode, or convert a value to make its structure visible.
Verify
Check syntax, expected formats, and documented limitations before shipping.
Apply
Copy the result into your project and review it against your application requirements.