Unix Timestamp Converter

Paste an epoch value or a date string and get the other instantly. Seconds and milliseconds are detected automatically.

NOW (seconds)

NOW (milliseconds)

NOW (ISO 8601)

Timestamp or date string

EPOCH SECONDS

EPOCH MILLISECONDS

ISO 8601 (UTC)

ISO 8601 (LOCAL)

LOCAL TIME

UTC TIME

RELATIVE

Walkthrough

How to use it

Type a Unix epoch value (in seconds or milliseconds) into the field — the unit is detected automatically.
Or paste any date string the browser understands, like 2024-01-01T12:00:00Z.
The equivalent epoch values, ISO 8601 forms, local/UTC times, and a relative description update as you type.
Use the copy buttons to grab the value in the format you need.

Use cases

When you'd use this

Reading a timestamp from logs. Most backends log epoch seconds or milliseconds — convert them before filing the bug report.

Writing a date into an API call. Turn a human date into the epoch value your API expects, without a calculator.

Double-checking expiry values. JWT exp claims, cookie lifetimes, and cache headers all use epoch time — this tells you when they actually run out.

FAQ

Common questions

How do you detect seconds vs milliseconds?

Values larger than 100 billion are treated as milliseconds, everything else as seconds. That covers virtually every real timestamp — if your value is ambiguous, try the other unit and compare the year.

What date formats are accepted?

Anything the browser's Date parser accepts — ISO 8601 (2024-01-01T12:00:00Z), plain dates (2024-01-01), and common variants. If it doesn't parse, the status line tells you.

Is anything sent to a server?

No. All conversion happens locally with JavaScript's built-in Date, in your browser tab.