Unix Timestamp Converter
Convert Unix timestamps to human dates and back — seconds or milliseconds, any timezone.
Free · No sign-up · Runs locally in your browser · Also available in Chinese (中文)
What is Unix Timestamp Converter?
A Unix timestamp is the number of seconds elapsed since 1 January 1970 00:00:00 UTC. Because it is a single integer, it is the universal language for storing moments in time: databases, log files, JWT tokens and API responses all use it, immune to timezone confusion and daylight-saving jumps.
This converter works both directions and auto-detects whether your input is in seconds or milliseconds (13-digit values). It shows the result in your local timezone and in UTC simultaneously, plus ISO 8601 format that you can paste straight into code or configuration.
How to use it
- 1Paste a timestamp (10-digit seconds or 13-digit milliseconds) to see it as a date.
- 2Or pick a date and time with the controls to get its timestamp.
- 3Check both the local-time and UTC rows to be sure which one you need.
- 4Copy the ISO 8601 string, the timestamp, or the formatted date with one click.
Common use cases
- Decoding the iat / exp fields of a JWT to check token expiry times.
- Converting log-file timestamps into readable dates during an incident investigation.
- Generating a timestamp for a cron schedule or an API request parameter.
Frequently asked questions
▸Why does my 10-digit timestamp show a date in 1970 or far future?
You are probably feeding seconds into a field that expects milliseconds (or vice versa). 10-digit values are seconds, 13-digit values are milliseconds — the tool auto-detects, but double-check the century of the result.
▸Do timestamps depend on my timezone?
The number itself never changes — it always refers to an absolute moment in UTC. Only its human-readable rendering differs per timezone, which is why the tool shows both.