dev
Developer Tools
Free online developer utilities — Base64 encoder, regex tester, cron expression builder, Unix timestamp converter, and color contrast checker.
The small conversions that interrupt real work: decoding a Base64 blob, testing a regex against sample text, writing a cron expression you can trust, turning a Unix timestamp into a date, or checking a color pair against WCAG. Each one does its job without an account, an upload, or a network request.
5 tools in this category
Base64 Encoder / Decoder
Encode and decode Base64, Base64URL, URL encoding, hex, and HTML entities. File support for images and documents. Runs client-side.
Category: devColor Contrast Checker
Check color contrast ratios for WCAG 2.2 AA and AAA compliance with APCA support, color blindness simulation, and auto-fix suggestions. Runs client-side.
Category: devCron Expression Builder
Visual cron expression builder with interactive field selectors, presets, next execution preview, and crontab output. Runs client-side.
Category: devRegex Tester
Test regular expressions with real-time match highlighting, capture groups, replace mode, and common pattern presets. Runs in your browser.
Category: devUnix Timestamp to Date Converter
A Unix timestamp counts seconds since 1970-01-01 UTC. Convert one to a date and back, seconds or milliseconds, in 11 time zones — all in your browser.