Unix Timestamp Converter

Convert Unix seconds or milliseconds to a readable UTC date without sending data anywhere.

● Calculated locally in your browser

Unix timestamp

Seconds or milliseconds

10 digits are treated as seconds; 13 digits as milliseconds.

Readable date · UTC

2025-01-01 00:00:00 UTCWednesday, January 1, 2025

What is a Unix timestamp?

A Unix timestamp counts elapsed time since 00:00:00 UTC on January 1, 1970. Most systems use seconds; JavaScript and some APIs commonly use milliseconds.

Seconds vs milliseconds

ObservKit treats values with at least 12 digits of magnitude as milliseconds and smaller integer values as seconds. Negative timestamps represent dates before 1970.

Example

1735689600 seconds and 1735689600000 milliseconds both represent January 1, 2025 at 00:00:00 UTC.