Free Developer Tools
Quick utilities for everyday jobs. Everything runs locally in your browser: nothing you paste is uploaded.
Cron Expression Explainer
Translate a cron expression into plain English and preview the next run times.
Volumetric Weight Calculator
Work out dimensional (volumetric) weight and the chargeable weight carriers will bill you for.
JSON Formatter & Validator
Pretty-print, minify and validate JSON, with precise error locations. Nothing leaves your browser.
Regex Tester
Test JavaScript regular expressions live, with highlighted matches and capture groups.
Color Contrast Checker
Check text and background colors against WCAG 2.2 AA and AAA contrast requirements.
Unix Timestamp Converter
Convert Unix epoch timestamps (seconds or milliseconds) to dates and back.
Base64 Encoder / Decoder
Encode text to Base64 or decode it back, with full UTF-8 and URL-safe support.
UUID Generator
Generate cryptographically random UUID v4 or time-ordered UUID v7 identifiers in bulk.
Business Days Calculator
Add working days to a date or count business days between two dates, excluding weekends and your holidays.
UTM Link Builder
Build clean campaign-tracking URLs with UTM parameters, and strip existing trackers.
JWT Decoder
Decode JSON Web Tokens to inspect the header, payload and expiry. Decoding happens locally; nothing is uploaded.
Hash Generator (SHA-256, SHA-1, SHA-512)
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text with the Web Crypto API.
URL Encoder / Decoder
Percent-encode or decode URLs and query parameters, and break a URL into its parts.
HTTP Status Codes Reference
Searchable reference of HTTP status codes with plain-English meanings and when APIs should use them.