Cassidor Tools
Free developer tools that just work.
Fast, private, browser-based utilities for developers. Format, convert, validate, encode, decode, generate, and debug without uploading your data.
Popular tools
Most used by developers
JSON Formatter
Beautify, validate, and clean up JSON data in your browser.
JSON Validator
Check whether your JSON is valid and pinpoint the exact error.
JSON Minifier
Compress JSON into a compact single-line format.
JSON Diff
Compare two JSON payloads and highlight what changed.
JSON to YAML
Convert JSON into readable YAML output instantly.
JWT Decoder
Decode JWT headers and payloads locally without exposing secrets.
Base64 Encoder / Decoder
Encode or decode Base64 text in the browser with no upload.
URL Encoder / Decoder
Encode and decode URL-unsafe characters safely.
UUID Generator
Generate v4 UUIDs instantly for IDs, tokens, and test data.
Unix Timestamp Converter
Convert precise timestamps between Unix time and human-readable dates.
Regex Tester
Test regular expressions against text and inspect matches quickly.
SQL Formatter
Prettify SQL for easier review, debugging, and documentation.
Categories
Browse by type
Format, validate, transform, and compare JSON data.
Encode, decode, and inspect common web values.
Create safe values and sample data for development.
Convert between structured data formats and timestamps.
Format and validate SQL, regex, and source snippets.