What does this tool do?
Convert a Unix timestamp or date string into ISO 8601, UTC, local time, and human-readable relative time. Everything runs locally using JavaScript in your browser — nothing you paste or upload is ever sent to a server.
How to use this tool
- Paste your timestamp or date into the left-hand box.
- Click Convert.
- Copy the converted formats from the output box.
Frequently asked questions
How does it know if my timestamp is in seconds or milliseconds?
Based on digit count — timestamps with 13 or more digits are treated as milliseconds, shorter ones as seconds. This covers all dates from the 1970s through the year 2286.
Can I enter a date string instead of a numeric timestamp?
Yes, any date string your browser can parse (e.g. "2026-01-15" or "Jan 15 2026") works as input, not just numeric Unix timestamps.
What does the relative time output mean?
It shows how far the timestamp is from right now in your browser, e.g. "3 days ago" or "in 2 hours", using the largest sensible unit.