Timestamp Converter

The Timestamp Converter turns Unix timestamps (seconds or milliseconds since 1970-01-01 UTC) into human-readable dates in your local timezone, UTC and ISO 8601 format — and vice versa. It handles both 10-digit second-based and 13-digit millisecond-based timestamps automatically, so you don't have to guess which format an API is returning.

Every backend developer works with timestamps. Log files, database records, JWT claims, HTTP headers (Date, Last-Modified, If-Modified-Since), API responses, cron schedules — they're all timestamps. When something goes wrong at 2:47:31 UTC, you need to translate that to your local wall-clock time and vice versa. This tool does the conversion in one paste.

Also useful for setting cache TTLs, calculating expiry times (add X seconds to now), and answering 'what will `now + 7 days` be as a Unix timestamp?' for setting cookie or session expiry. Every conversion happens in your browser using the built-in Date object, so it's fast and private.