Unix Timestamp Converter

Free Unix Timestamp Converter that works offline

Convert Unix epoch timestamps into ISO 8601, UTC and local date formats, or turn a local date into seconds and milliseconds since the epoch. Ten-digit values are treated as seconds and larger modern values as milliseconds.

What this unix timestamp converter does

Unix time counts elapsed time from 1970-01-01 00:00:00 UTC, which avoids locale-specific date strings in storage and APIs. A timestamp itself does not contain a time zone. Time zones matter only when the same instant is formatted for people or when a local calendar value is interpreted.

How to use the Unix Timestamp Converter

1. Enter a numeric timestamp in seconds or milliseconds and convert it.
2. Alternatively choose a local date and time from the browser control.
3. Compare ISO, UTC, local, seconds and millisecond results.
4. Copy the exact representation required by your API, database or log query.

Common uses

• Reading created_at and expires_at fields from APIs
• Converting log timestamps during debugging
• Building test fixtures for scheduled behavior
• Comparing UTC instants with the browser’s local time zone

Private processing and offline access

This tool does not submit your input to a conversion server. Processing takes place inside the browser using local JavaScript and standard Web APIs. After the PWA has been installed or cached, the page and its core features remain available without an internet connection. Closing or clearing the page removes unsaved input; the tool does not create an account or cloud history.

Tips for accurate results

• Store machine timestamps in UTC and convert to local time only for display.
• Confirm whether an API expects seconds or milliseconds; confusing them changes the date dramatically.
• Local date conversion uses the device time zone and clock settings.

Frequently asked questions