Seconds or milliseconds — how does auto-detect work?

Any 10-digit number is treated as seconds (Unix epoch through 2286). 13-digit numbers are treated as milliseconds. You can override the detection in the dropdown.

What's the Year 2038 problem?

32-bit signed Unix timestamps overflow at 03:14:07 UTC on 2038-01-19. Modern systems use 64-bit timestamps and aren't affected. This tool handles both.

Does it handle leap seconds?

Unix time ignores leap seconds by design — every day is exactly 86,400 seconds. So does this tool, which matches all standard programming languages.

Why does my date show one day off?

Almost always a timezone issue. Make sure you're comparing the same timezone on both sides — UTC is the safest baseline.

Timestamp Converter — Free Online Tool

Unix Timestamp (seconds)

ISO: 1970-01-01T00:00:00.000Z

UTC: Thu, 01 Jan 1970 00:00:00 GMT

Local: Thu Jan 01 1970 00:00:00 GMT+0000 (Coordinated Universal Time)

What is the Timestamp Converter?

The Timestamp Converter is a free online date & time from Markvibe. Convert Unix timestamps to human dates. It runs entirely in your browser — your data never gets uploaded — and works on desktop, tablet and mobile with no sign-up.

Reviewed by The Markvibe Team · Last updated 2026-06-28

Example

A worked example so you know exactly what to expect.

Input

(your input goes here)

Output

(the Timestamp Converter runs in your browser and shows the result instantly)

How to use Timestamp Converter

1Paste a Unix timestamp (seconds or milliseconds — auto-detected) or an ISO 8601 date string.
2Get instant conversions: UTC, your local timezone, ISO 8601, RFC 2822, relative ("3 hours ago"), and Unix in both seconds and ms.
3Switch the timezone dropdown to view the same moment in any IANA timezone (America/New_York, Asia/Tokyo, Europe/London…).
4Click "Now" to fill the input with the current timestamp; click any output to copy it.
5Bulk mode: paste a column of timestamps to convert them all at once.