Unix Timestamp Converter – Seconds or milliseconds to dates

Paste a Unix epoch value, click Convert, and read UTC as an ISO string plus your local clock string. Values with 13 or more digits are treated as milliseconds; shorter ones as seconds.

Updated 2026-08-03 · time

Click Convert.

About this tool

Unix time counts seconds or milliseconds since 1970-01-01 UTC. This converter takes one numeric field, detects second versus millisecond length, builds a Date, then prints UTC and Local lines—or Invalid timestamp when the value cannot be parsed.

How to use

  1. Open the converter: Load Unix Timestamp Converter in a modern browser.
  2. Enter the timestamp: Paste seconds or a 13-digit millisecond value into Unix timestamp.
  3. Convert: Click Convert to build the Date from your number.
  4. Read UTC and Local: Use the UTC ISO line and Local line in the result.

Common use cases

Tips

FAQ

How are seconds and milliseconds chosen?

Truncated digit length of 13 or more means milliseconds; otherwise the value is treated as seconds.

What formats appear in the result?

UTC as an ISO string and Local as the browser date string.

Why do I see Invalid timestamp?

The number is not finite or does not produce a valid Date.

Can I convert a date back to a timestamp?

Not on this page—it only converts timestamp to UTC and local text.

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