Calm tools for busy developers

Pretty-print, validate, and inspect JSON with optional minify and key sorting.

Compare two JSON documents, highlight changes, and generate a merged output.

Convert and debug text encodings in your browser: URL encode/decode, HTML entities, Unicode code points, JSON/JS string escaping, and charset byte views (UTF-8/UTF-16/Latin-1).

Encode or decode Base64 and URL-safe Base64 in your browser, with UTF-8 and padding control.

Generate QR codes from text or URLs, or decode them from image files — all in your browser.

Break down any URL into protocol, host, path, query parameters, and fragments — parsed instantly in your browser.

Decode and inspect JSON Web Tokens, understand header and payload, and see claims at a glance.

Generate UUID v4/v1/v7 and customizable NanoIDs with optional prefixes, suffixes, and bulk export.

Compute MD5, SHA-1, SHA-256, and SHA-512 for text or files, with optional HMAC for each algorithm.

Convert Unix timestamps to human-readable datetimes with timezone, ISO 8601, and RFC3339 support. Runs entirely in your browser.

Convert YAML to JSON and JSON to YAML with live parse errors and pretty-printed output.

Convert between binary, decimal, and hex with BigInt support and a byte-order visualizer.

Generate TypeScript interfaces or types from JSON, with configurable key styles (original, camelCase, snake_case).

Send GET, POST, PUT, and DELETE requests with JSON or form bodies, custom headers, and a live response inspector.

Inspect which modern Web APIs your current browser actually supports, see permission status, and try them out in a safe, developer-focused playground. Perfect for PWA, H5 games, and Web SDK authoring.

Test JavaScript regular expressions with real-time matches, highlighting, flags, and common pattern templates.

Parse a 5-field cron expression, explain each segment, and preview upcoming run times in your local timezone.

Generate a color palette from a base color, with optional swatches and export options.