Timestamp Converter

Timestamp Converter is a free online tool that converts between Unix timestamps (epoch time) and human-readable date formats. Unix timestamps represent the number of seconds (or milliseconds) elapsed since January 1, 1970 UTC, and are widely used in programming, databases, and APIs for storing and transmitting date and time information.

The tool supports conversion in both directions: enter a Unix timestamp to see the corresponding date and time, or enter a date to get the Unix timestamp. A timestamp is shown as ISO 8601, a human-readable date in your local time zone, a UTC line and relative time (e.g., "2 hours ago"); a date is shown as Unix seconds, milliseconds and ISO 8601.

Whether you are a developer debugging API responses, a system administrator analyzing log files, or anyone working with timestamps in code, this tool gives instant conversions. It reads timestamps in seconds, returns both seconds and milliseconds when you convert a date, and shows the current Unix timestamp ticking in real time.

Here is the Unix timestamp to date converter at work. Type 1609459200 into Unix Timestamp (seconds) and the panel shows ISO 8601 2021-01-01T00:00:00.000Z, UTC Fri, 01 Jan 2021 00:00:00 GMT, the same moment in your local time zone, and a relative line (5 years ago as of September 2026). As a date to Unix timestamp converter it reads the Date & Time field as local time, so on a computer set to UTC, 1 January 2021 at 00:00 returns 1609459200 and 1609459200000 milliseconds. Paste 1700000000000 into the seconds box instead and the date lands in the year 55840, which tells you the value was milliseconds.

Unix time counts seconds from midnight UTC on 1 January 1970, and two details cause most of the confusion. The first is units: JavaScript, Java and many APIs work in milliseconds while C, PHP, Python and most databases work in seconds, so a value that decodes to a moment in January 1970 was almost certainly seconds read as milliseconds, and one landing fifty thousand years out is milliseconds read as seconds. The digit count tells you which: ten digits is seconds, thirteen is milliseconds. The second is the 2038 problem. A signed 32-bit integer runs out on 19 January 2038, and any system still storing timestamps that way will wrap to 1901. Unix time also ignores leap seconds by definition, so it is not a count of elapsed physical seconds and never has been.