What is a Unix timestamp?

A Unix timestamp is a numeric value that represents time elapsed since January 1, 1970 at 00:00:00 UTC.

Does this converter support milliseconds?

Yes. The converter accepts 10-digit second timestamps and longer millisecond timestamps.

Why do local and UTC times differ?

UTC is a global time standard. Local time includes your browser timezone offset.

Can I convert the current time?

Yes. Use the secondary action to convert the current browser time.

Why do some APIs use milliseconds?

Milliseconds give higher precision for logs and event timing, but many systems still store standard Unix seconds.

How are JWT timestamps related?

JWT claims such as exp, iat, and nbf are often Unix timestamps, so this converter helps you read them.

Time tool

Unix Timestamp Converter

Convert Unix timestamps into readable local time, UTC time, ISO strings, seconds, and milliseconds.

Unix timestamp or date

Converted time Ready

Use cases

Convert timestamps used in logs, APIs, databases, and tokens.

Debug logs

Convert numeric timestamps from logs and monitoring tools into readable values during incident review.

Check API data

Inspect timestamp fields in API responses, webhook payloads, database rows, and scheduled jobs.

Common mistakes

Seconds and milliseconds are easy to confuse. A 10-digit value is usually seconds, while 13 digits is usually milliseconds.

Basics

What Unix timestamps are and when to use them.

A Unix timestamp counts time from the Unix epoch: January 1, 1970 at 00:00:00 UTC. It is a compact and language-agnostic way to represent time in logs, databases, APIs, and auth claims. Seconds are the traditional format. Milliseconds are also common when systems need more precision.

This converter is especially useful with JWT claims such as exp, iat, and nbf, with API payloads that use numeric time fields, and with logs that need to be compared across time zones. Pair it with the JWT Decoder when you are reading token claims, the JSON Formatter when the timestamp is inside a payload, and the SQL Formatter when you are reviewing database queries that store time values.

Examples

Practical examples and everyday workflows.

In JavaScript, Date.now() returns milliseconds since the epoch. In Python, the time and datetime modules are the usual helpers. Those values are easy to convert into readable strings when a bug report includes only a raw number or when a JWT expires sooner than expected.

If a token seems valid in JSON but still fails, compare the time fields against the current browser clock and the server clock. A small clock skew can produce a visible failure. That is why time conversion is one of the fastest ways to debug authentication issues in practice.