UNIX timestamp converter

What this tool does

Numeric values below 1e12 are treated as seconds. Larger values are treated as milliseconds. ISO-8601 strings parse with the JavaScript Date parser. The output includes the host timezone name from the browser.

How to use it

1. Paste a timestamp or ISO date.
2. Read UTC, local, and both UNIX units.
3. Use Now to capture the current instant.

Privacy

This tool processes files and text locally in your browser. Your content is not uploaded or stored by this site.

ConvertPass does not include your input in analytics, URLs, or error reports. Encoding: ASCII / ISO-8601. Limit: 4 KB (4.0 KB).

Limitations

• The JavaScript Date range does not cover every historical calendar quirk.
• Timezone conversion uses the browser's zone, not a selected IANA zone other than the host.

Example

1700000000

{
  "unixSeconds": 1700000000,
  "isoUtc": "2023-11-14T22:13:20.000Z"
}

Troubleshooting

The year looks like 1970 or 56000

You mixed seconds and milliseconds. A 13-digit number is usually milliseconds.

FAQ

Is UNIX time UTC?

UNIX time counts seconds since 1970-01-01T00:00:00Z, not counting leap seconds in the usual POSIX definition.

Does this handle leap seconds?

No. JavaScript Date does not expose leap seconds. For civil time this rarely matters; for scientific time it does.

Can I convert JWT exp values?

Yes. exp is usually UNIX seconds. Paste the number from the JWT decoder.

Why include local time?

Because humans debug logs in their own zone. UTC is still the canonical field.