Unix Timestamp Converter

Epoch time made readable

A Unix timestamp counts the seconds since 1 January 1970 UTC. This converter shows the current epoch live and converts any timestamp — auto-detecting seconds versus milliseconds — into UTC, local, ISO 8601 and a friendly relative time.

It also works in reverse: pick a date and time to get the exact timestamp in both seconds and milliseconds.

Handy for

• Debugging APIs and logs
• Setting expiry times in code
• Converting database timestamps

Key features at a glance

• Shows the current Unix time live
• Auto-detects seconds versus milliseconds
• Outputs UTC, local, ISO 8601, and relative time
• Converts dates back to a timestamp in seconds and milliseconds
• Runs entirely in your browser
• Works offline once the page has loaded

What a Unix timestamp is

A Unix timestamp, also called epoch time, is the number of seconds that have elapsed since midnight UTC on 1 January 1970 — a moment known as the Unix epoch. By representing any instant as a single integer counting from that fixed point, computers can store and compare times without worrying about time zones, calendars, or formatting. It is the universal clock that underpins most software.

This simplicity is why timestamps are everywhere in technology: databases record them, APIs return them, log files are stamped with them, and programs use them to schedule and expire things. A timestamp is unambiguous and easy to do arithmetic on — subtracting two of them gives the seconds between two events directly. The trade-off is that the raw number is meaningless to a human, which is exactly what this converter fixes.

Seconds versus milliseconds

A common source of confusion is that timestamps appear in two scales. The classic Unix timestamp counts whole seconds, while many modern systems — JavaScript in particular — count milliseconds, a thousand times larger. A seconds timestamp for a recent date is ten digits long; the millisecond version is thirteen. Mixing them up shifts a date by decades, a frequent bug when one system expects seconds and another supplies milliseconds.

This converter detects which scale you have entered based on its magnitude, so you do not have to specify it, and when converting a date to a timestamp it gives you both forms side by side. Understanding the distinction helps you feed the right value into whatever system you are working with, avoiding the puzzling errors that arise when a timestamp lands in 1970 or far in the future because the units were wrong.

The year 2038 problem

Unix timestamps have a famous limitation. Systems that store the timestamp as a signed 32-bit integer can only count up to 2,147,483,647 seconds, a value reached at 03:14:07 UTC on 19 January 2038. Beyond that the number overflows and wraps around to a negative value, potentially sending affected software back to 1901 — an issue dubbed the Year 2038 problem, reminiscent of Y2K.

Modern systems increasingly use 64-bit integers, which push the limit billions of years into the future and make the problem moot for them. But legacy hardware and software that still rely on 32-bit time remain at risk and are gradually being updated. Knowing this context explains why you may occasionally see strange dates near 2038, and why the move to 64-bit timekeeping matters.

Tips for working with timestamps

• Check the digit count: ten digits is seconds, thirteen is milliseconds
• Store and compare times as timestamps to avoid timezone bugs
• Use UTC timestamps for anything shared across regions
• Subtract two timestamps to get the exact seconds between events
• Convert to ISO 8601 when you need a human-readable, sortable date

Why choose our Unix timestamp converter?

Our converter is completely free with no signup, no limits, and no subscription. It runs entirely in your browser, so conversions are instant, it works offline, and nothing you enter is sent to a server.

It is one of more than 200 free tools on ToopTools, and you can pin it to your My Workspace, a personalized workspace where you arrange the tools you use most into a single dashboard. Beside the timezone converter and other developer and time tools, it keeps epoch conversions a click away.

Common use cases

Developers use the Unix timestamp converter to debug APIs and logs, where times are stored as epoch values that need decoding into readable dates. They also use it to set expiry times in code and to make sense of timestamps pulled from a database.

It is equally handy for converting a human date into the timestamp a system expects, checking when a token or cache entry will expire, and confirming that two systems agree on a time. The live current epoch is a quick reference whenever you need the present moment as a timestamp.

Is the Unix timestamp converter free?

Yes. It is completely free with no account, no sign-up, and no usage limits. Convert as many timestamps as you like at no cost.

What is the Unix epoch?

The Unix epoch is midnight UTC on 1 January 1970, the zero point from which Unix timestamps count seconds. Every timestamp is simply the number of seconds elapsed since that moment.

Is my timestamp in seconds or milliseconds?

Count the digits: a current timestamp in seconds has ten digits, while milliseconds has thirteen. The converter auto-detects the scale, but checking the length helps you supply the right value to other systems.

Can I convert a date back to a timestamp?

Yes. Pick a date and time and the converter returns the exact Unix timestamp in both seconds and milliseconds, so you can use whichever form your application requires.

Why does my timestamp show the wrong date?

Usually the units are mismatched — a millisecond value read as seconds lands far in the future, and the reverse lands in 1970. Confirm whether the value is in seconds or milliseconds and convert accordingly.

Are my conversions kept private?

Yes. Everything is computed in your browser and nothing is uploaded, so the values you enter stay private and the tool works without an internet connection.

How do I convert a Unix timestamp to a date?

Paste your Unix timestamp and the tool instantly shows the matching date and time in both your local zone and UTC. It detects whether the value is in seconds or milliseconds, and you can also enter a date to convert it back into a timestamp.

Does the Unix timestamp converter work offline?

Yes. The conversion runs entirely in your browser using your device's clock, so once the page has loaded the tool works without an internet connection, and nothing you enter is uploaded — it stays private on your own device.