FREE WEB TOOL

Unix timestamp converter

Convert Unix seconds / milliseconds and human-readable dates.

Use tool

Unix time / date-time

How to use it

Convert Unix timestamps and date-time strings into readable local time, ISO 8601, Unix seconds and Unix milliseconds in one result.

Enter a Unix value or a date-time string.
Select Convert, or use Use current time to insert the current timestamp.
Read the ISO, local, seconds and milliseconds forms.

Numeric ≤10 digits: Treated as Unix seconds
Numeric 11–16 digits: Treated as Unix milliseconds
Date-time text: Parsed by the browser Date implementation
Output: ISO / Local / seconds / milliseconds

Seconds vs milliseconds can look like a completely wrong date

1757910000 and 1757910000000 differ in digit count but can represent the same instant when one is seconds and the other milliseconds.

For date-time text, a timezone-explicit ISO value such as 2026-09-15T10:30:00+09:00 avoids much of the ambiguity of regional date formats.

Unix time counts from 1970-01-01 UTC

A Unix timestamp is an elapsed-time number, not a timezone label. The instant is fixed, while the human-readable local display depends on the viewer’s timezone.

ISO is UTC; Local uses the device timezone

The ISO result uses a UTC Z form. Local is formatted in the browser’s current locale and timezone. ISO is usually the safer form to exchange between systems.

Digit count distinguishes seconds and milliseconds here

For numeric-only input, this tool treats up to 10 digits as seconds and 11–16 digits as milliseconds. For present-day timestamps, the familiar patterns are roughly 10 and 13 digits.

Avoid ambiguous regional date strings

A value such as 09/10/2026 may be interpreted differently across environments. Use ISO 8601 with an explicit offset when you need repeatable conversion.