Unix timestamp converter
Turns a Unix timestamp into a readable date, and back – in your browser.
Runs in your browser – your file is never uploaded
Frequently asked questions
Is my file uploaded?
No. The conversion runs entirely in your browser. The file never leaves your device – there is no server that could see it. Once the page has loaded, the tool even works offline.
Seconds or milliseconds – how do you tell?
By size. A ten-digit number is seconds (the usual Unix convention); a thirteen-digit one is milliseconds, which is what JavaScript's Date.now() returns. The boundary is unambiguous in practice: 1e12 milliseconds is the year 2001, while 1e12 seconds would be the year 33658.
Which time zone is “local”?
Your computer's. The tool reads the setting from your browser, so the local line matches what your own clock shows. UTC and ISO 8601 are always given as well, and those are the same for everybody.
Can I convert a date back into a timestamp?
Yes, that is the same box. Type 2026-08-25 14:30 or an ISO string and you get the Unix value in seconds and milliseconds. Leave it empty to see the current time.
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