Convert a Unix timestamp
Turn Unix timestamps into readable dates, and back again.
What to know
Numeric input of ten digits or fewer is read as seconds; anything longer is read as milliseconds. That is the convention almost every system follows, and it disambiguates the two without asking.
Text input is parsed as a date and converted the other way. Results are shown in UTC to avoid the ambiguity that makes timestamp bugs so hard to find.
Questions
Is anything uploaded to a server?
No. Every tool on this site runs inside your browser using standard web APIs. There is no upload, no account, no logging and no server holding your data afterwards. You can confirm it by opening your browser's developer tools and watching the network tab stay empty while you work.