Timestamp Converter

Convert a Unix timestamp into readable UTC, local, and ISO 8601 dates, or pick a date and time to get the epoch value back in seconds and milliseconds. Both seconds and millisecond timestamps are detected automatically, so you do not have to work out which one you pasted.

Unix Timestamp → Date

Unix Timestamp (seconds or milliseconds)

Date → Unix Timestamp

Date and Time

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Why use Timestamp Converter?

A Unix timestamp is one number describing one instant: the seconds elapsed since the start of 1970 in UTC. Because it carries no time zone and no formatting convention, it is unambiguous in a way that a written date never is. There is no question of whether 03/04 means March the fourth or the third of April. The awkwardness comes from units. Older systems and most command line tools use seconds, while JavaScript and many modern APIs use milliseconds. A value in the wrong unit is out by a factor of a thousand, which puts a 2026 date somewhere in 1970 or far into the future. This converter reads the digit count and picks the right unit, which removes the most common source of confusion. Three output formats are given because each has its place. UTC is the neutral reference, local time answers what actually happened on your clock, and ISO 8601 is what you paste back into code. Having all three at once saves converting twice when you are checking something quickly.

Key benefits

Seconds and milliseconds detected from the length of the value, with no toggle to set
Three readable formats produced at once from a single timestamp
Both epoch units returned when converting a date, ready for whichever API you are calling
Every output field is individually copyable
A clear message when a value cannot be read, rather than an empty panel

Features

Automatic unit detection based on digit count
UTC and local time shown side by side so offsets are visible
ISO 8601 output, the format most APIs and databases expect
Use Now button to stamp the current moment
Runs entirely in the browser

Popular use cases

Reading a timestamp out of a log file or database row
Building a test fixture that needs a specific epoch value
Checking whether an expiry stored in a token has already passed
Comparing a server timestamp against your own local clock

How to use Timestamp Converter

1
Paste a timestamp
Drop a Unix epoch value into the first field. It is prefilled with the current time so you can see the format straight away.
2
Read all three formats
UTC, your local time, and the ISO 8601 string are shown together, each with its own copy button.
3
Convert a date instead
Use the date and time picker lower down to go the other way and get the epoch value.
4
Copy the format you need
Seconds and milliseconds are both given, since different systems expect different units.

Frequently asked questions

What is a Unix timestamp?

A count of how much time has passed since midnight UTC on 1 January 1970, called the Unix epoch. Storing an instant as a single number avoids all the ambiguity of time zones and date formats, which is why it is so widely used in logs, databases, and APIs.

Seconds or milliseconds, how does it know?

By the length of the number. A seconds timestamp for any recent date is ten digits, while a millisecond value is thirteen. Anything longer than ten digits is treated as milliseconds, so you can paste either without changing a setting.

Why do UTC and local time differ?

The timestamp itself has no time zone, it is a single instant. UTC shows that instant at the zero meridian, and local time shows the same instant on your machine's clock, adjusted for your offset and daylight saving. Both are correct, they are two views of one moment.

What is ISO 8601 and why use it?

It is the international standard format, written as year, month, day, then a T, then the time with a Z for UTC. Sorting ISO strings alphabetically also sorts them chronologically, which is a large part of why APIs and databases prefer it.

Why does my date picker result differ by a few hours?

The picker gives a wall clock time with no zone attached, which is read against your local offset. If you are comparing against a UTC value from a server, the difference you see is your own offset from UTC.

Last reviewed: July 2026

Unix Timestamp → Date

Date → Unix Timestamp

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