Developer / Tools

14 utilities: IP subnet (CIDR → mask + hosts + broadcast), subnet mask converter (dotted ↔ CIDR), MAC OUI lookup, Base64 encode/decode, URL encode/decode, HTML entity encode/decode, hash generator (SHA-1/256/384/512), UUID generator, password generator (configurable charset), password strength meter (entropy), random string generator, bandwidth / download time, color converter (HEX ↔ RGB ↔ HSL), and cron expression helper.

Yes — every developer tool runs in your browser. Base64, hashes, UUIDs, passwords — none of it is sent to a server. Safe to use for sensitive data.

Entropy in bits = length × log₂(charset size). 60+ bits = strong, 80+ = very strong. The verdict scale: < 28 weak, 28-60 reasonable, 60-128 strong, > 128 very strong (passphrases). It does NOT check against breached-password lists.

v4 is the universally-supported random-UUID standard. The page uses the browser's `crypto.randomUUID()` which is cryptographically secure on all modern browsers.

Five fields, space-separated. Examples: `0 9 * * 1-5` = 9 AM weekdays. `*/15 * * * *` = every 15 minutes. The Cron Helper calculator builds the expression interactively and explains it in plain English.

Only IPv4 currently. IPv6 subnet math is straightforward but the UX is different — coming in the next developer-tools expansion.