Convert epoch timestamps to dates and back — seconds or milliseconds, UTC and local time.
This free tool converts Unix epoch timestamps to human-readable dates and back, entirely in your browser. It auto-detects whether a timestamp is in seconds or milliseconds and shows the result in UTC, ISO 8601, and your local time zone.
Unix time (or epoch time) counts the number of seconds that have elapsed since 00:00:00 UTC on January 1, 1970, ignoring leap seconds. It's a single, timezone-independent number, which makes it a common choice for storing timestamps in databases, log files, and APIs — comparisons and arithmetic on dates become simple integer math.
The original Unix standard uses seconds (10-digit numbers for dates in the 2000s-2280s range). JavaScript's Date.now() and many modern web APIs use milliseconds instead (13-digit numbers), for finer-grained precision. This tool detects which unit you've entered based on digit count, so you don't have to convert manually.
Systems that store Unix time as a signed 32-bit integer can only represent values up to 2,147,483,647 seconds after the epoch — which overflows on January 19, 2038 at 03:14:07 UTC. Most modern 64-bit systems have no such limit, but some older embedded systems and legacy software remain at risk, similar to the Y2K bug.
The number of seconds elapsed since 00:00:00 UTC on January 1, 1970 (the Unix epoch) — a compact, timezone-independent way to represent a point in time.
10-digit timestamps are in seconds; 13-digit timestamps are in milliseconds (used by JavaScript and many modern APIs). This tool auto-detects the unit.
Systems using a signed 32-bit integer will overflow on January 19, 2038. Modern 64-bit systems aren't affected, but some legacy systems are.
A Unix timestamp is always UTC. This tool shows both the UTC value and your browser's local time zone equivalent side by side.