About Timestamp Converter
A Unix timestamp is a count of seconds since 1 January 1970 UTC, which makes it easy for computers and awkward for people. Logs, databases, APIs and JWT claims all use variations of it, and a value in milliseconds looks almost identical to one in seconds until the resulting date lands decades away.
This converter shows both directions and three renderings — ISO 8601, the UTC representation and the browser's local time — so you can check the same instant from different angles. A live clock shows the current seconds and milliseconds for quick comparisons, and every output line has a copy button.
What this tool does
Seconds and milliseconds
Enter either unit or let auto detection apply the common 10-digit and 13-digit heuristics, and see which unit was used.
Date to timestamp as well
Turn a local date and time back into Unix seconds and milliseconds, which is useful for building test fixtures and API calls.
ISO 8601, UTC and local
Each result shows the same instant in the ISO 8601 format, the UTC string and the browser's local date and time.
Live current time
A clock at the top of the tool shows the current Unix seconds, milliseconds and ISO timestamp, updating once a second.
Relative time
See how long ago or from now the timestamp is, in a readable form such as 3 days ago or in 2 hours.
Validation and copy buttons
Out-of-range timestamps and invalid local dates fail with a clear message, and every output line can be copied on its own.
How to use Timestamp Converter
- 01
Enter a Unix timestamp
Paste the number into the timestamp field and leave the unit on Auto, or pick seconds or milliseconds explicitly.
- 02
Read the converted dates
Compare the ISO 8601, UTC and local renderings, and use the relative line to judge how recent the moment is.
- 03
Or start from a date
Use the date and time field on the right to get Unix seconds and milliseconds for a specific local time.
- 04
Copy the value you need
Each output row has its own copy button, so you can take the ISO string, the seconds or the milliseconds into another tool.
Supported formats and limits
- Input
- UNIXISO 8601
- Output
- Date
- Processing
- Client-side, in your browser. Nothing is uploaded.
- Maximum size
- Bound by the memory available to your browser tab.
- Requirements
- Chrome, Edge, Firefox or Safari · JavaScript enabled
Limitations worth knowing
- Only the browser's local time zone and UTC are shown; there is no selector for arbitrary named time zones.
- Daylight-saving gaps are rejected and repeated local hours are ambiguous, so unusual local times should be verified against UTC.
- Output precision is limited to milliseconds, so microseconds from a database timestamp are truncated.
Privacy and file handling
Timestamp conversion happens entirely in your browser. The values you enter are not uploaded, stored or logged, and the live clock runs on your own device rather than a server.
Read the full privacy policy