Unix timestamp converter
Convert Unix seconds or milliseconds to UTC and ISO dates, or turn a UTC date into a timestamp. Choose units explicitly.
Free · No signup · Processed in your browserLoading the interactive tool…
How to use this tool
- Enter a timestamp and choose seconds or milliseconds.
- Convert to ISO and UTC time.
- Use the reverse form to convert a UTC date into a timestamp.
How it works
Unix timestamps measure elapsed time from 1 January 1970 at 00:00:00 UTC. APIs often use seconds; JavaScript uses milliseconds. For example, 1,700,000,000 seconds is 2023-11-14T22:13:20.000Z.
What to check before using the result
Units are never guessed from the number of digits. UTC is explicit to avoid silent local-time differences. Leap-second handling follows JavaScript Date rather than representing leap seconds as a separate value.
BEFORE YOU GO
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Are my files, text or numbers uploaded?
No. This tool processes the input in your browser tab. It does not send your input to our servers. Leaving or refreshing the page clears the working input.
Do I need an account or subscription?
No account is required for this public tool. You can complete the task and download the result directly. An account is useful when you want to measure visits to your own website or manage tracked campaign links.
Can I share or link to this tool?
Yes. Use the tool link below in a tutorial, team resource list or campaign checklist. The link opens an empty tool; your private input is not included.
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