Unix Timestamp Converter
Turn a Unix timestamp into a readable date, or a date back into a timestamp — with UTC, local time and the relative age.
How to convert a timestamp
- Paste a Unix timestamp in seconds or milliseconds, or type a date in almost any common form.
- Press Convert, or press Use the current time to fill in the timestamp for right now.
- Read the result: Unix seconds, Unix milliseconds, ISO 8601, UTC, local time and how long ago it was — all from one input.
The tool tells you which way it read your input. A value of ten digits or fewer is treated as seconds; anything longer is treated as milliseconds.
Reading timestamps out of logs and APIs
A Unix timestamp is the number of seconds that have elapsed since midnight on 1 January 1970, UTC — the Unix epoch. It is popular for a simple reason: it is a single integer, it sorts correctly as a number, it takes no account of daylight saving or time zone rules, and it is identical no matter where in the world the machine reading it happens to be.
The cost of that simplicity is that the number means nothing to a human. When an API returns 1735689600 or a log line ends in 1735689600, the only way to know what it refers to is to convert it. That is what this page does, and it deliberately shows several forms at once, because the right one depends on what you are doing.
ISO 8601 — 2025-01-01T00:00:00.000Z — is the form to use in data and in code, since it sorts correctly as text and states its time zone explicitly. UTC is the form to use when talking to someone in another country, because there is no ambiguity about which midnight you mean. Local time is the form to use when you are working out whether an event happened before or after something you remember. The relative age is usually the fastest sanity check of all: if a log entry says "3 days ago" when you expected it to be from this morning, you have found your bug.
Timestamp converter FAQ
Is the timestamp in seconds or milliseconds?
The tool decides by length. Values up to ten digits are treated as seconds, the classic Unix time used by most APIs. Longer values are treated as milliseconds, which is what JavaScript's Date and many mobile SDKs produce.
Why does the local time differ from UTC?
A Unix timestamp is a point in time, not a clock reading. The same instant is a different hour in every time zone, so UTC is shown next to your own local time to remove the ambiguity.
What is the Unix epoch?
Midnight on 1 January 1970, UTC. Unix time counts the seconds since that moment, which keeps timestamps small, sortable and free of time zone rules.
When will Unix time run out?
A signed 32-bit counter overflows on 19 January 2038 — the Y2K38 problem. Any system that stores Unix time in a 64-bit integer is unaffected.
Related tools
- JSON Formatter and Validator — read the API response the timestamp came from.
- UUID Generator — identifiers for log correlation.
- SHA Hash Generator — checksums for payloads.
- All developer tools — eight browser-based utilities.