Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back — seconds or milliseconds, entirely in your browser.
100% in your browser
No watermark
No sign-up
How it works
- Paste a Unix timestamp (seconds or milliseconds) — the tool auto-detects which unit you used.
- Instantly see the equivalent UTC, local, ISO 8601 and relative representations.
- Or pick a date and time to get its Unix second and millisecond values.
- Click any Copy button to grab the result. Nothing leaves your browser.
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 1 January 1970 (the "Unix epoch"). It is timezone-agnostic and widely used in APIs, databases, and log files.
- How does the tool tell seconds from milliseconds?
- Any value greater than 10 billion (10¹⁰) is treated as milliseconds. Values at or below that threshold are treated as seconds. This covers all realistic dates from 1970 through the year 2286 correctly.
- What does "Relative" mean?
- "Relative" shows how long ago or from now the timestamp falls — for example "3 days ago" or "in 2 hours". It updates every second while the page is open.
- Is my data sent to a server?
- No. All conversions happen entirely in your browser using the built-in JavaScript Date API. No data is uploaded or logged.