Unix Timestamp Converter
Free Unix timestamp converter for seconds, milliseconds, and date-time values with Local and UTC output processed in your browser.
100% browser-onlyTool Workspace
Every conversion uses the browser clock and does not depend on server time.
Options
10 digits usually means seconds and 13 digits usually means milliseconds. Choose a unit for other lengths.
Result
Privacy Notice：Your files are processed locally. They are never uploaded.
About this tool
Convert Unix seconds, milliseconds, and date-time values in both directions with clear Local, UTC, ISO 8601, and relative-time output.
Convert seconds and milliseconds
Auto-detect treats 10 digits as seconds and 13 digits as milliseconds. Choose a unit manually for other lengths, including negative timestamps before 1970.
Convert a date to a timestamp
Enter a date, time, and either Local or UTC to get Unix seconds and Unix milliseconds. Local uses this device's browser timezone.
How to use this tool
- Enter Unix seconds or milliseconds, or provide a date, time, and timezone.
- Confirm the unit or timezone, then run the conversion.
- Review Local, UTC, ISO 8601, relative time, or timestamp output.
Private, local processing
Every calculation runs locally in this browser. Your input is not sent to or stored by NexaForge servers.
Frequently asked questions
Does this tool use server time?
No. Current Timestamp and relative time use the current clock in this browser.
How does it distinguish seconds from milliseconds?
Auto-detect treats 10 digits as seconds and 13 digits as milliseconds. Choose a unit manually for other values.
Can it handle dates before 1970?
Yes. The browser Date API supports negative seconds and milliseconds before the Unix epoch.
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