Unix Timestamp Converter
Convert Unix seconds, milliseconds and readable dates instantly in your browser.
Unix timestamp converter
Date and Unix values
- Unix seconds
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- Unix milliseconds
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- UTC date and time
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- Your local date and time
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- ISO 8601
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- Relative time
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What is a Unix timestamp?
A Unix timestamp measures elapsed time since January 1, 1970 at 00:00:00 UTC. Many APIs use seconds, while JavaScript and some databases commonly use milliseconds.
Automatic detection treats values with 12 or more digits as milliseconds. Select the input unit manually when working with unusually old, future or fractional timestamps.
Seconds, milliseconds and time zones
Timestamp bugs often happen because two systems use different units. Unix seconds are common in APIs, logs and databases. Unix milliseconds are common in JavaScript, browser events and some telemetry systems. The same moment can therefore appear as a 10-digit or 13-digit value.
A Unix timestamp itself is based on UTC and does not contain a time zone. Time zones are applied only when displaying the value as a readable date. This converter shows UTC, local time and ISO 8601 output so you can compare what an API stores with what a user sees.
Why is my converted date off by a few hours?
The timestamp is probably correct, but it is being displayed in a different time zone. Compare the UTC output with your local output before changing stored data.
What is ISO 8601?
ISO 8601 is a standard readable date format such as 2026-06-30T12:00:00.000Z. It is
useful in APIs because it can make the UTC offset explicit.