Free Online Developer Tools

Fast, lightweight utilities for everyday development. Every tool runs entirely in your browser, so your data never leaves your device.

Data & JSON

Beautify, validate, and minify JSON instantly with clear error messages.

Escape and unescape JSON strings for safe embedding in code and URLs.

Convert text to and from Base64 with full Unicode support.

Percent-encode and decode URL components for query strings and paths.

Convert text between UPPERCASE, lowercase, Title, camelCase, snake_case, and kebab-case.

Clean up text by removing duplicate lines and blank lines in one click.

Generate MD5 and SHA-256 hashes directly in your browser, no upload.

Generate one or many RFC 4122 v4 UUIDs instantly in your browser.

Convert Unix timestamps to human-readable UTC and local dates and back.

Convert colors between RGB, HEX, and HSL with a live color preview.

Check TLS certificate expiry for multiple hosts at once via Certspotter, plus SSL Labs deep scans for the real served certificate and grade.