About this tool
Timestamp Converter is a free online tool that translates Unix timestamps into human-readable dates and back. It handles both seconds and milliseconds, detects the format automatically, and shows the result in ISO 8601, your local time zone, UTC, and as a relative phrase ("5 minutes ago"). Everything runs locally in your browser - no server, no signup, no tracking.
How it works
1
Paste a timestamp or a date
Enter a Unix timestamp (seconds or milliseconds - both work) in the left panel, or pick a date and time in the right panel.
2
Read the result instantly
The tool converts in real time as you type. You get ISO 8601, local time, UTC, and a relative phrase - all at once, no button to press.
3
Copy any value with one click
Click any output row to copy it to your clipboard. Perfect for pasting into code, logs, bug reports, or documentation.
Frequently Asked Questions
What is a Unix timestamp? v
A Unix timestamp is the number of seconds that have passed since 1 January 1970, 00:00:00 UTC - a moment known as the Unix epoch. It is a universal way to store time that does not depend on time zones or calendar quirks.
How do I tell seconds from milliseconds? v
Seconds are 10 digits today (around 1.7 billion), while milliseconds are 13 digits (around 1.7 trillion). The tool detects the format automatically: if the number is larger than 10^11, it treats it as milliseconds.
Does the tool work with any time zone? v
Yes. The tool uses your browser's local time zone for the "Local time" row and always shows UTC in a separate row. If you need a specific time zone, copy the ISO 8601 value and convert it in your own tools.
Is my data sent to a server? v
No. Every conversion happens directly in your browser using the built-in JavaScript Date API. No timestamps, dates, or any other data leave your device.