Timestamp Converter
Turn Unix seconds or milliseconds from logs and APIs into readable dates, and the other way around. Nothing is uploaded.
Processed in your browser
Examples: 1700000000, 1700000000000, 2023-11-14T22:13:20Z
Advanced options
Paste a timestamp or datetime, then convert.
Features
Both directions
Convert Unix time to a date, and ISO or wall-clock time back to Unix seconds and milliseconds.
Unit detection
Tell seconds from milliseconds, microseconds, and nanoseconds by magnitude — or lock the unit.
Time zones
Read the instant in UTC plus everyday zones such as Tokyo and New York.
Current time
Load this device's current instant as Unix seconds and ISO 8601.
How to use
- Paste a Unix timestamp or a datetime.
- Choose Convert. Use Now when you need the current instant.
- Check seconds, milliseconds, ISO, and the time zone, then copy if needed.
Why this tool
Runs in the browser
Core work finishes in this tab.
No upload
Pasted text and local files are not sent away for processing.
Free, no account
The core path has no signup wall.
Immediate
There is no upload-and-wait queue.
Japanese and English
The same tool ships at / and /en/.
Readable failures
Broken input returns a reason, not a blank screen.
FAQ
- Is my input uploaded?
- No. Conversion runs in this browser. Pasted timestamps and datetimes are not sent.
- How do you tell seconds from milliseconds?
- Auto mode uses magnitude (about 10 digits for seconds, 13 for milliseconds). You can lock the unit in Advanced options.
- How is a datetime without a zone handled?
- Values without Z or an offset are read as wall time in the selected time zone.
- Are microseconds and nanoseconds exact?
- JavaScript time is millisecond precision. Finer units are rounded to milliseconds.