Timestamp Converter
Convert Unix seconds or milliseconds to readable dates in any timezone, and back again.
Unix timestamp → date
Date → unix timestamp
Seconds
Milliseconds
How to use it
- Type a Unix timestamp into the first field. Values above ~1 trillion are auto-detected as milliseconds.
- The full local date and time is shown immediately.
- To go the other way, pick a date in the second field and read the equivalent seconds and milliseconds.
- Use Now to stamp the current moment in both units.
Common use cases
- Reading API errors —
"expires_at": 1725931234becomes a date you can actually reason about. - Writing database queries — compute the epoch value for "start of today" or "30 days ago" in one step.
- Log forensics — translate a Unix-prefixed log line into your local time without mental math.
FAQ
Q: Seconds or milliseconds — how do I know which I have? A: If the number is 10 digits (about a billion) it is seconds; 13 digits (about a trillion) is milliseconds. The tool auto-detects and you can also inspect the rendered year to confirm.
Q: Does it convert to UTC? A: It renders in your browser's local timezone and shows the UTC equivalent if you read the ISO fields. For a fixed-zone comparison, use the timestamp output against a UTC clock.
Q: What is the maximum representable date? A: JavaScript dates span roughly 1970 ± 285,000 years, which covers every practical timestamp.
Your data stays on this device
Timestamp Converter runs 100% locally. Everything you paste or drop is processed by your own browser and never transmitted. Nothing is stored on our servers — close the tab and it is gone.
Nothing you type is sent to a server, logged, or used for analytics. The page works even with your network disconnected after first load.