Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back, instantly.
Unix time represents a moment as the number of seconds elapsed since midnight UTC on January 1, 1970 (the "Unix epoch") — a compact, timezone-agnostic format that's easy for computers to store and compare, but effectively meaningless to a human reading it directly. Almost every backend system, log file, and API response uses Unix timestamps internally, which means developers regularly need to convert one to a readable date to actually understand what it represents.
This tool converts in both directions: paste a Unix timestamp (in seconds) and instantly see it as an ISO 8601 string, a UTC date, your browser's local time, and a human-friendly relative description ("3 hours ago", "in 2 days"); or pick a date and time and get back its Unix timestamp in both seconds and milliseconds, since some systems (notably JavaScript's own Date.now()) use milliseconds instead of seconds and mixing the two up is a very common bug.
All conversions use your browser's built-in Date object and Intl.RelativeTimeFormat, so daylight saving transitions and calendar edge cases are handled correctly rather than approximated.
How to use Unix Timestamp Converter
- 1
Convert from a timestamp
Paste a Unix timestamp in seconds to see it as ISO, UTC, local time, and a relative description.
- 2
Use current time
Click Use current time to instantly load the current Unix timestamp.
- 3
Convert from a date
Pick a date and time in the second section to get its Unix timestamp in both seconds and milliseconds.
Features
- Converts Unix timestamp to ISO 8601, UTC, and local time simultaneously
- Human-friendly relative time descriptions
- Converts a picked date/time back to Unix seconds and milliseconds
- Correctly handles daylight saving and timezone edge cases
Frequently asked questions
Common mistakes to avoid
- Confusing seconds-based Unix timestamps with millisecond-based ones from JavaScript's Date.now().
- Assuming a displayed local time is UTC, or vice versa, when comparing timestamps across systems in different timezones.
- Forgetting that Unix time is timezone-agnostic — it always represents the same instant regardless of where it's displayed.
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