27 tools

Developer tools

Everyday encoding, hashing, formatting, and inspection tools for building things.

Developer tools that keep your data in the browser: format and validate JSON, convert JSON and CSV, preview Markdown, compare two texts, test regular expressions, encode and decode Base64, URLs and HTML entities, make hashes and UUIDs, decode JWTs, convert number bases and timestamps, work out IP subnets, chmod values and cron schedules, look up HTTP status codes, and build CSS gradients and shadows. Paste tokens and payloads without sending them to a server.

JSON, data and text testing

Format and validate JSON, convert between JSON and CSV, preview Markdown, compare two texts and test regular expressions.

JSON formatter & validator JSON to CSV converter CSV to JSON converter Markdown previewer Diff checker Regex tester

Encoding, hashing and IDs

Base64, URL and HTML entity encoding, hashes, JWT decoding, UUIDs, number bases and Roman numerals, and password strength.

Base64 encode & decode URL encode & decode HTML entities encoder and decoder Hash generator JWT decoder UUID generator Number base converter Roman numeral converter Password strength checker

CSS and colour

Minify CSS, turn pixels into rem, check colour contrast against WCAG, build gradients and shadows, and convert colour codes.

CSS minifier and beautifier px to rem and em converter Colour contrast checker CSS gradient generator CSS box-shadow generator Colour converter

URLs, networks and servers

Take a URL apart, work out IP subnets, explain cron expressions and chmod permissions, look up HTTP status codes and convert Unix timestamps.

URL parser IPv4 subnet calculator Cron expression explainer Chmod calculator HTTP status codes reference Timestamp converter