What is a Unix timestamp?
A Unix timestamp counts the seconds since January 1, 1970 (UTC) — the "epoch." It's how computers, databases and APIs store time in a single number, independent of timezone or format. For example, 1735689600 is January 1, 2025, 00:00 UTC.
This tool converts both directions and shows a live-ticking current timestamp. It auto-detects milliseconds (13-digit) versus seconds (10-digit) input.