Convert between Unix timestamps and human-readable dates. Auto-detects seconds vs milliseconds.
Unix timestamps are commonly stored as seconds since 1970-01-01 UTC, but many APIs (especially JavaScript) use milliseconds. If your converted date looks far in the future, you likely pasted milliseconds into a seconds field (or the reverse).
| Input | Meaning |
|---|---|
1700000000 | Seconds timestamp |
1700000000000 | Milliseconds timestamp |
When debugging logs, prefer ISO-8601 (2026-05-23T12:34:56Z) for copy/paste safety across timezones.