Convert epoch ↔ human date both ways. Auto-detects seconds vs milliseconds, shows local, UTC, ISO 8601 and relative time — with one-click copy.
🔒 Everything is computed locally in your browser.
Paste the epoch from a stack trace or DB row and instantly see when it happened in your time zone.
Pick a date and time, get seconds and milliseconds — ready for tokens, expiry fields and cron jobs.
A date in 1970 or the year 56,000? You mixed up seconds and milliseconds — the auto-detect flags it.
It's in milliseconds but was read as seconds (or it's simply small). 13-digit numbers are milliseconds; divide by 1000 for seconds. The converter detects this automatically.
Systems storing seconds in signed 32-bit integers overflow on Jan 19, 2038. Modern 64-bit systems and JavaScript (which uses milliseconds in doubles) are unaffected.
Yes — paste anything like 2026-06-10T14:30:00Z and it converts the other way, too.