Free Unix Timestamp Converter
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About the Unix Timestamp Converter
Convert Unix timestamps to readable dates and back — seconds or milliseconds auto-detected, with local, UTC and ISO 8601 output, all in your browser.
How to use the Unix Timestamp Converter
- 1Paste a Unix timestamp on the left — seconds or milliseconds are detected automatically.
- 2Read the date in your local time, UTC and ISO 8601.
- 3Going the other way? Pick a date and time on the right to get its timestamp.
- 4Click Now to grab the current timestamp.
Frequently asked questions
What is a Unix timestamp?
The number of seconds since 1 January 1970 UTC (the "epoch"). It's how most databases, APIs and log files store time — one unambiguous number, no time zones.
How do I know if my timestamp is seconds or milliseconds?
Count the digits: 10 digits is seconds, 13 is milliseconds. This tool detects it automatically — 1700000000 and 1700000000000 both convert to the same date.
Why does the local time differ from UTC?
A timestamp is an absolute moment; local and UTC are just two ways to display it. This tool uses your device's time zone for the local reading.
What is the year 2038 problem?
Old 32-bit systems store timestamps in a signed 32-bit integer, which overflows on 19 January 2038. Modern 64-bit systems — and JavaScript — are unaffected.
Is anything sent to a server?
No — conversion happens entirely in your browser using your device's clock and time zone.