Free tools
Timestamp Converter
Convert Unix timestamps and ISO dates with timezone detail.
Processed in your browser. Your input is not uploaded.
Input
Choose seconds or milliseconds when needed. Include a timezone in date strings, for example Z or +08:00.
Ctrl / Cmd + Enter to runResult
Your result will appear here.
About this tool
Translate a numeric Unix timestamp or an ISO date into useful representations. Explicit units help avoid ambiguous values, while the result makes UTC and the browser’s local timezone distinct.
When to use it
- Inspect timestamps in logs and API data.
- Compare seconds and milliseconds.
- Read a timezone-aware ISO date.
How to use it
- Enter a timestamp or an ISO date with Z or an explicit offset.
- Select seconds, milliseconds or auto-detection.
- Convert and copy individual time values from the result table.
Input and output example
Input
1735689600 seconds
Output
2025-01-01T00:00:00.000Z
Important details
- Auto-detection is a convenience; explicitly select units for ambiguous numeric values.
- Date strings must include a timezone; invalid calendar dates are rejected.
- Local time uses the browser timezone, not an assumed account profile setting.
Frequently asked questions
Why do two numeric values show very different dates?
They may use different units. Millisecond timestamps are normally 1,000 times the corresponding second value.
Does conversion change the stored time?
No. It displays representations of the entered instant and does not update a server record.