Unix Timestamp Converter

Convert Unix timestamps online

Paste a Unix timestamp (seconds or milliseconds) and see the equivalent ISO 8601 date, UTC string, and your local time instantly. Or go the other way — type any date string and get the Unix seconds and milliseconds back. Everything runs locally in your browser; nothing is uploaded.

The Auto-detect unit mode uses a simple heuristic: any value with an absolute value of 1 trillion or more is treated as milliseconds, smaller values as seconds. This covers all timestamps from 1970 through roughly year 33658 in seconds, and from 1970 through 2001 in milliseconds.

FAQ

What is a Unix timestamp? It is the number of seconds (or milliseconds) elapsed since 1 January 1970 00:00:00 UTC, ignoring leap seconds.

Seconds or milliseconds? Most Unix system calls use seconds. JavaScript's Date.now() returns milliseconds. When in doubt, enable Auto-detect.

What date formats are accepted? Any string parseable by the browser's Date constructor — ISO 8601 is safest (e.g. 2024-06-15T08:30:00Z).

Is my data sent anywhere? No. All conversion happens client-side.