Unix Timestamp Converter

Convert Unix/epoch timestamps to human-readable dates and back — seconds or milliseconds.

Updated: June 27, 2026

Enter a Unix timestamp (seconds or milliseconds).

Convert epoch time in both directions

A Unix timestamp (also called epoch time) is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, not counting leap seconds. It's the universal way computers store time. This converter turns a timestamp into a readable date — in UTC, ISO 8601, and your local timezone — and converts a date back into a timestamp. Everything runs in your browser.

Seconds vs milliseconds

The most common source of bugs with epoch time is the unit. Unix time is classically measured in seconds, but JavaScript and many APIs use milliseconds (seconds × 1000). A 10-digit number is almost always seconds; a 13-digit number is milliseconds. The converter auto-detects this, or you can force the unit. If your date comes out in 1970, you probably fed seconds where milliseconds were expected, or vice versa.

What the outputs mean

ISO 8601 (UTC) — the unambiguous machine format, e.g. 2026-06-27T10:00:00.000Z. Use this in APIs and logs.
UTC — the same instant in Coordinated Universal Time, human-readable.
Local time — the instant in your browser's timezone.
Relative — how long ago or how far in the future the moment is.

Common uses

Reading a timestamp from a log file, database row or JWT exp claim.
Generating the current epoch time to paste into a config or test.
Checking whether a token or cache entry has expired.
Converting between an API's timestamps and a human-friendly date.

The 2038 problem (briefly)

Systems that store Unix time in a signed 32-bit integer will overflow on 19 January 2038, wrapping to a negative number. Modern systems use 64-bit time and are unaffected, but it's worth knowing if you maintain legacy code. This tool uses JavaScript numbers, which comfortably handle dates far beyond 2038.

Timezones and related tools

Epoch time has no timezone — it's a single instant. The timezone only matters when you display it, which is why we show both UTC and your local time. To inspect a token whose expiry is an epoch timestamp, use the JWT decoder; to format the surrounding data, try the JSON formatter.

Frequently asked questions

What is a Unix timestamp?

It's the number of seconds since 00:00:00 UTC on 1 January 1970 (the Unix epoch), excluding leap seconds. It's a timezone-independent way to represent a single instant in time.

Is my timestamp in seconds or milliseconds?

A 10-digit value is typically seconds; a 13-digit value is milliseconds. This tool auto-detects, but you can force the unit. If your converted date lands near 1970, the unit is probably wrong.

Why does the local time differ from UTC?

A timestamp is a single instant with no timezone. UTC and your local time are two displays of that same instant offset by your timezone. The underlying epoch value is identical.

Does epoch time account for leap seconds?

No. Unix time deliberately ignores leap seconds, treating every day as exactly 86,400 seconds. This keeps arithmetic simple at the cost of not being a perfect count of elapsed SI seconds.

Logging & observability tools

If you read timestamps from logs all day, these help:

Log management / observability platform Automatically parse and display timestamps in your timezone, and correlate events across services.
API client Inspect and convert timestamp fields in requests and responses while testing APIs.