Unix Timestamp Converter
Convert between Unix/epoch timestamps and human dates — both directions, in seconds and milliseconds, local time and UTC. The live clock ticks in real time. Everything runs in your browser.
Current time · live
Timestamp → date
Date → timestamp
What a Unix timestamp is
A Unix timestamp (a.k.a. epoch time) is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970 — the "Unix epoch" — not counting leap seconds. It's timezone‑independent: the same instant is the same number everywhere on Earth, which is exactly why systems store and exchange time this way.
Seconds vs milliseconds
Unix time is classically counted in seconds. JavaScript, Java and many APIs instead use milliseconds (seconds × 1000). A quick tell: a seconds value for a recent date is ~10 digits; the millisecond version is ~13. The Auto mode here uses that digit count to guess the unit, but you can force it.
Time zones & ISO 8601
An epoch value is an absolute instant; a human date only makes sense with a time zone. This tool shows both your local time and UTC. The ISO 8601 form (e.g. 2023‑11‑14T22:13:20.000Z) is the unambiguous machine format — the trailing Z means UTC ("Zulu").
The Year 2038 note
Systems that store the timestamp in a signed 32‑bit integer overflow on 19 January 2038. Modern platforms (and this tool, via JavaScript's 64‑bit Number) use 64‑bit time, so the problem doesn't apply here.
Privacy
Every conversion happens locally with the browser's built‑in Date object. Nothing is sent anywhere.