Free Online Unix Timestamp Converter Tool
Convert Unix/POSIX timestamps to human-readable dates and times instantly. Supports both seconds and milliseconds format, with multiple timezone display options. Perfect for developers working with APIs, databases, and log files. 100% client-side.
Detected: Seconds format
JavaScript Date API · 100% client-side
How to Use the Unix Timestamp Converter Tool
Enter a Timestamp
Type or paste a Unix timestamp (in seconds or milliseconds) into the input field. The tool auto-detects the format.
Auto-Convert Instantly
The tool instantly converts your timestamp to multiple date formats including UTC, local time, ISO 8601, and relative time.
Copy or Convert Back
Copy any formatted date to your clipboard, or use the date picker to convert a date back to a Unix timestamp.
Powerful Unix Timestamp Converter Features
Everything you need to convert Unix timestamps — all in one free tool.
Seconds & Milliseconds
Auto-detects both 10-digit (seconds) and 13-digit (milliseconds) timestamps. No switching required.
Multiple Date Formats
View the converted date in UTC string, local time string, ISO 8601, and relative time all at once.
Bidirectional Conversion
Convert timestamps to dates AND dates back to timestamps. Both sides update in real-time.
Copy Any Format
Copy the timestamp or any date format to your clipboard with a single click.
Relative Time
See the relative time display (e.g., '2 hours ago', 'in 3 days') for easy understanding.
Current Timestamp
One-click button to insert the current Unix timestamp for quick reference.
Clear & Sample
Load sample timestamps or clear all fields instantly.
100% Client-Side
All conversions happen in your browser. Your data stays private.
Why Use Our Unix Timestamp Converter Tool
The fastest way to convert Unix timestamps. Accurate, multi-format, and private.
100% Free
No hidden fees, no usage limits. Convert as many timestamps as you need.
Dual Format Support
Auto-detects seconds and milliseconds — no need to specify the format.
Real-Time Bidirectional
Change the timestamp or the date and both update instantly.
Developer-Friendly
Perfect for debugging API responses, reading log files, and working with databases.
Key Highlights
- No sign-up required
- 100% client-side
- Seconds & milliseconds auto-detect
- UTC, local, ISO & relative formats
- Bidirectional conversion
- Works on any device
Frequently asked questions
What is a Unix timestamp?
A Unix timestamp (also called POSIX time or epoch time) is the number of seconds or milliseconds that have elapsed since January 1, 1970, 00:00:00 UTC. It's a universal time format used by most operating systems, databases, and APIs.
Is this timestamp converter really free?
Yes, completely free. No hidden charges, no usage limits.
How do I know if my timestamp is in seconds or milliseconds?
The tool auto-detects: 10-digit timestamps are seconds, 13-digit timestamps are milliseconds. You can see which format was detected in the output.
Can I convert dates before 1970?
Yes! Unix timestamps can be negative for dates before January 1, 1970. The tool supports negative timestamps for historical dates.
What is the year 2038 problem?
The Year 2038 issue affects 32-bit systems where timestamps overflow. JavaScript uses 64-bit numbers, so this tool can handle dates far beyond 2038.
Do I need to install anything?
No installation required. Works entirely in your web browser.
Can I use this on my phone?
Yes, fully responsive and works on all devices.