19 free developer tools — no sign-up required

Free Online Developer Tools

JSON formatter, Base64 encoder, JWT decoder, regex tester and 15 more tools. Everything runs locally in your browser — your data never leaves your machine.

⌘K
No signup or account
Data stays in your browser
100% free forever
Works offline

JSON Tools

{ }
JSON Formatter
Beautify and format JSON with syntax highlighting
JSON Validator
Validate JSON syntax and find errors instantly
JSON Minifier
Compress and minify JSON to reduce file size
JSON Tree Viewer
Visualize JSON as an interactive collapsible tree
JSON Diff Checker
Compare two JSON objects and highlight differences

Encode & Decode

64
Base64 Encoder/Decoder
Encode text and files to Base64 and decode back
URL Encoder/Decoder
Encode and decode URLs and query strings
<>
HTML Encoder/Decoder
Encode HTML entities and decode them back
Gzip Compress/Decompress
Compress and decompress data with Gzip

Converters

JSON to CSV
Convert JSON arrays to CSV format instantly
CSV to JSON
Convert CSV files to JSON format
JSON to XML
Convert JSON to XML with custom root element
JSON to YAML
Convert JSON to YAML and YAML to JSON

Developer Utilities

JWT Decoder
Decode JWT tokens and inspect claims
.*
Regex Tester
Test and debug regular expressions with live highlighting
Markdown Preview
Write Markdown and preview rendered HTML
Color Converter
Convert colors between HEX, RGB, HSL and more
#
Hash Generator
Generate MD5, SHA-1, SHA-256 and SHA-512 hashes
±
Text Diff Checker
Compare two texts and highlight differences