Unix Timestamp Converter
Free online Unix timestamp converter to convert between epoch timestamps and human-readable dates in ISO, UTC, and local formats.
Timestamp → Date
iso
2026-03-30T05:19:36.000Z
utc
Mon, 30 Mar 2026 05:19:36 GMT
local
2026-03-30 05:19:36
relative
0s ago
Date → Timestamp
What Is a Unix Timestamp?
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC—a reference point known as the Unix epoch. It is the most universal way to represent a specific moment in time across programming languages, databases, APIs, and operating systems. This tool converts Unix timestamps to human-readable dates and vice versa, supporting both seconds and milliseconds precision.
How to Use the Unix Timestamp Converter
- Enter a Unix timestamp in the 'Unix Timestamp' field to convert it to a date.
- Select whether the timestamp is in seconds or milliseconds.
- Click 'Now' to populate the current Unix timestamp.
- View the converted date in ISO 8601, UTC, local, and relative time formats.
- To convert a date to a timestamp, enter a date string (e.g., '2024-01-01T00:00:00Z') in the 'Date String' field.
- Copy any result using the copy button next to each value.
Common Use Cases
- API Debugging — Convert timestamps from API responses or JWT tokens into readable dates to verify expiration times, created-at fields, and event timing.
- Database Queries — Translate between epoch values stored in databases and human-readable dates when writing or debugging queries.
- Log Analysis — Convert epoch timestamps found in application or system logs into local time to correlate events and diagnose issues.
- Cross-Timezone Coordination — Use Unix timestamps as a timezone-neutral reference point when coordinating events or deadlines across distributed teams.
FAQ
What is the difference between seconds and milliseconds timestamps?
A seconds timestamp counts whole seconds since the Unix epoch (e.g., 1700000000), while a milliseconds timestamp includes three extra digits for millisecond precision (e.g., 1700000000000). JavaScript's Date.now() returns milliseconds, while most Unix tools use seconds.
What date formats are accepted for conversion?
The tool accepts ISO 8601 format (2024-01-01T00:00:00Z), common date strings (Jan 1 2024), and most formats that JavaScript's Date constructor can parse.
What happens with timestamps before 1970?
Timestamps before the Unix epoch (January 1, 1970) are represented as negative numbers. The tool can convert negative timestamps to their corresponding dates.
Is the 'relative' time updated in real time?
The relative time is calculated when the timestamp is entered or changed. It shows an approximation like '5h ago' or '3d from now' based on the difference from the current moment.