Unix Timestamp Converter - Epoch Time to Date Online
Bidirectionally convert Unix timestamps (seconds or milliseconds) and datetimes (ISO 8601, local, relative). Displays the current time in real time and supports timezone conversion.
Client-Side & Privacy-First:
Your data and files are never sent to any server. Everything is
processed safely within your browser.
How to Use
- Click "Use current time" to fill the input with the current Unix timestamp
- Enter a number in the timestamp field to convert to datetime
- Select a date in the datetime field to convert to timestamp
- Switch between seconds and milliseconds in the options
- Select a timezone to change the local time display
Usage Examples
Inspect API response datetime: 1700000000 corresponds to 2023-11-14T22:13:20Z in ISO 8601.
Timezone conversion: Convert a UTC timestamp to Japan time (Asia/Tokyo).
Millisecond timestamps: JavaScript's Date.now() returns milliseconds; use ms mode for conversion.
FAQ
- What is a Unix timestamp?
- The number of seconds (or milliseconds) elapsed since the Unix epoch: January 1, 1970, 00:00:00 UTC.
- Is there a year-2038 issue?
- No. This tool uses JavaScript Numbers, not 32-bit integers, so the 2038 problem does not apply.
- Are negative timestamps supported?
- Yes, for dates before 1970.
- What is the difference between seconds and milliseconds?
- Seconds are classic Unix time (e.g. 1700000000); milliseconds are used by JavaScript Date (e.g. 1700000000000).
- Is data sent to a server?
- No. Everything runs in the browser.
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Update History
Last Updated: 2026-02-20
- 2026-02-20 Initial release