Developer

Unix Timestamp Converter

Turn Unix timestamps into readable local, UTC and ISO 8601 dates with a relative time summary, or pick a date to get its timestamp. Auto-detects seconds vs milliseconds and includes a one-click Now button.

Examples

Input · Interpreted as seconds.

1735689600

Output

2025-01-01T00:00:00.000Z (UTC)

How it works

A Unix timestamp counts the seconds since 1 January 1970 at 00:00 UTC. Type one in and the tool shows the same moment as local time, UTC, ISO 8601 and a relative phrase such as “3 days ago”. A number with 13 or more digits is read as milliseconds; anything shorter is read as seconds.

Reference values
Timestamp	UTC
0	1970-01-01 00:00:00
1735689600	2025-01-01 00:00:00
1735689600000	2025-01-01 00:00:00 (milliseconds)

Negative numbers are dates before 1970. In the other direction, the date picker uses your device’s time zone and returns the timestamp in both seconds and milliseconds.

How to use Unix Timestamp Converter

Enter a timestamp

Type a Unix timestamp in seconds, or paste a 13-digit value for milliseconds.

Or pick a date

Use the date and time picker to get the matching Unix timestamp.

Use Now if needed

Click Now to fill the current timestamp instantly.

Why use this tool

Auto-detects seconds vs millisecond timestamps

Shows local, UTC, ISO 8601 and relative time at once

Two-way conversion between dates and timestamps

Uses the browser's real Date — no server round-trip

Frequently asked questions

How does it know seconds vs milliseconds?

Values with 13 or more digits are treated as milliseconds; shorter values are treated as seconds.

Is the local time my time zone?

Yes. Local time uses your device's time zone, while UTC and ISO outputs are timezone-independent.

Found a bug or have an idea?

ToolOrbit is actively developed — feedback directly shapes what gets built next.

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