How to convert a Unix timestamp
- Paste a timestamp —
1751554800(seconds),1751554800000(milliseconds) — or any date string. Conversion is live. - Read the result in every format at once: Unix seconds, milliseconds, ISO 8601 UTC, your local time zone, and relative time ("in 3 days").
- Click Use current time to grab the epoch right now, and Copy output to take everything with you.
Seconds, milliseconds and the epoch
Unix time counts seconds since midnight UTC on January 1, 1970 — "the epoch". It's the backbone of computing time: log files, JWT exp claims, database columns, API responses and cron jobs all speak it. The classic bug is mixing units: JavaScript's Date.now() returns milliseconds while most APIs and JWTs use seconds, so a timestamp pasted into the wrong tool lands in the year 57519. This converter reads the number of digits and picks the right unit automatically, so 10-digit, 13-digit and 16-digit values all decode to the date you expect.
Frequently asked questions
What is a Unix timestamp?
The number of seconds elapsed since January 1, 1970 at 00:00 UTC. A single integer is unambiguous across time zones, which is why databases and APIs prefer it.
How do I tell seconds from milliseconds?
Current Unix time is 10 digits in seconds and 13 digits in milliseconds. The converter detects the unit from the magnitude automatically — 16-digit microsecond values work too.
Can I convert a date back to a timestamp?
Yes — paste an ISO 8601 string like 2026-07-03T15:00:00Z or a plain date like July 3, 2026 and you get Unix seconds and milliseconds instantly.
What is the year 2038 problem?
Signed 32-bit Unix time overflows on January 19, 2038. Modern 64-bit systems (and this tool) handle dates far beyond that.