Unix Timestamp Converter
Runs entirely in your browser
Convert Unix timestamps to dates, and dates to Unix timestamps, directly in your browser.
What is a Unix Timestamp?
A Unix timestamp counts the number of seconds (or milliseconds) since the Unix epoch — 00:00:00 UTC on January 1, 1970. It's widely used in APIs, databases and log files because it's unambiguous and timezone-independent.
How to use Unix Timestamp Converter
- Enter a timestamp (seconds or milliseconds) to see its date, or pick a date to see its timestamp.
- Use "Use Current Timestamp" to jump to right now.
- Read off Local time, UTC, ISO 8601, and both timestamp units.
Features
- Converts in both directions — timestamp to date and date to timestamp.
- Automatically detects seconds vs. milliseconds.
- Shows local time, UTC and ISO 8601 side by side.
- 100% client-side — your input never leaves your browser.
Example
Entering the timestamp 1700000000 (10 digits, so the tool reads it as seconds) produces:
- UTC:
Tue, 14 Nov 2023 22:13:20 GMT - ISO 8601:
2023-11-14T22:13:20.000Z - Unix seconds:
1700000000 - Unix milliseconds:
1700000000000
Local time depends on your browser's timezone — someone in New York (UTC-5 in November) would see 11/14/2023, 5:13:20 PM, while someone in Tokyo (UTC+9) would see 11/15/2023, 7:13:20 AM. The underlying moment in time is identical; only the displayed clock time changes.
Tips
- The seconds-vs-milliseconds detection is based purely on digit count: 13 or more digits (ignoring a leading minus) is read as milliseconds, anything shorter as seconds. A millisecond timestamp from before September 2001 has 12 digits or fewer and will be misread as seconds — if a converted date looks wildly wrong, check the digit count.
- The Date → Timestamp field uses an HTML
datetime-localinput, which carries no timezone information of its own — the value you pick is always interpreted in your browser's local timezone, never UTC. - Negative timestamps are accepted and represent moments before January 1, 1970 — useful for historical dates.
- Both fields stay in sync live: typing a timestamp updates the date picker, and picking a date updates the timestamp field, so you can cross-check a conversion either direction.
Is Unix Timestamp Converter safe?
Yes. Conversion runs entirely on the browser's built-in JavaScript Date API, using the digit-count detection described in the Tips above to tell seconds from milliseconds — nothing you type is sent to our servers, though timestamps aren't personal data to begin with.
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds (or milliseconds) that have elapsed since 00:00:00 UTC on January 1, 1970 (the Unix epoch).
How do I know if my timestamp is in seconds or milliseconds?
Seconds timestamps are 10 digits today (e.g. 1735689600); millisecond timestamps are 13 digits (e.g. 1735689600000). This tool detects the unit automatically based on digit count.
Why do the local and UTC times differ?
A Unix timestamp represents one exact moment in time. Local time shows that moment in your browser's timezone, while UTC shows the same moment with no timezone offset applied.