Free Online Timestamp Converter

Unix time (also called epoch time or POSIX time) counts the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, not counting leap seconds. It is the most common way computers store a point in time because it is a single integer, independent of timezone and locale. A present-day Unix timestamp in seconds is a 10-digit number; in milliseconds — the unit JavaScript's Date.now() returns — it is 13 digits. This converter works in both directions. Paste a timestamp to see it rendered as a UTC string, your local time, an ISO 8601 string, and a human-friendly relative time such as "3 days ago". Or paste a date and read back the equivalent Unix timestamp in seconds and milliseconds. Use the seconds/milliseconds toggle when a value looks off by a factor of 1000 — that almost always means the unit is mismatched. Everything runs locally using your browser's clock and timezone settings, so conversions reflect your machine's configuration and nothing is sent to a server. It is handy for debugging logs, API responses, database records, and JWT "exp" claims.