Unix Timestamp Converter
Convert Unix timestamps to human dates and dates back to epoch seconds. Handles seconds and milliseconds, in UTC and your local time.
- ✓ Runs in your browser — nothing uploaded
- ✓ No sign-up
- ✓ Free, no limits
This free Unix timestamp converter turns epoch time into a readable date and turns dates back into epoch seconds, both directions on one page. Paste a timestamp and see it in both UTC and your own local timezone; type an ISO date and get the matching Unix seconds. A “Now” button drops in the current timestamp for quick testing.
It handles the ambiguity that trips people up: values are auto-detected as seconds or milliseconds (13-digit numbers are treated as milliseconds), so a JavaScript Date.now() value and a server's epoch-seconds value both convert correctly without you doing mental maths. Showing UTC and local side by side removes the other classic confusion — a log line stamped in UTC versus what your users actually saw.
Unix time counts the seconds since 1 January 1970 UTC and is the timestamp format in logs, databases, JWTs and APIs everywhere. Everything here is computed locally in your browser with no server call. Worked example: 1704067200 is 2024-01-01T00:00:00Z, and the same instant given as milliseconds (1704067200000) converts identically.
Frequently asked questions
What is a Unix timestamp?
The number of seconds elapsed since 00:00:00 UTC on 1 January 1970 (the “epoch”). It is a compact, timezone-free way to store an instant, used across logs, databases and APIs.
How does it know if my number is seconds or milliseconds?
Values with 13 or more digits are treated as milliseconds (JavaScript's Date.now() format); shorter values are treated as seconds. Both convert to the same date.
Why show both UTC and local time?
Timestamps are stored in UTC but experienced locally. Showing both lets you match a UTC log entry to what a user in your timezone actually saw, avoiding off-by-hours mistakes.