Unix Timestamp Converter
Convert Unix timestamps to readable dates, and convert UTC or local dates back to epoch time. Everything runs in your browser.
Seconds and milliseconds
Most Unix timestamps are 10 digits in seconds. JavaScript and some APIs use 13-digit millisecond timestamps.
UTC and local output
UTC is stable across systems. Local output uses your device time zone, which is useful when reading browser logs or app events.
Private browser utility
All conversion runs locally in your browser. No timestamp, date or log value is uploaded to Convertr.
Related developer tools
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have passed since January 1, 1970 at 00:00:00 UTC. Many APIs, databases and logs use it to store time.
Does this converter use seconds or milliseconds?
It supports both. Shorter values are treated as Unix seconds, and longer 13-digit values are treated as milliseconds. You can also choose the unit manually.
Is the timestamp converted on the server?
No. All conversion runs locally in your browser. The timestamp or date you type is not uploaded.
Why do UTC and local time differ?
UTC is a global time standard. Local time applies your device time zone offset and daylight saving rules, so the displayed hour may be different.
Unix Timestamp Converter
Convert Unix seconds or milliseconds to readable dates and convert local or UTC dates back to epoch time.
- Input
- An epoch value or calendar date, precision, and UTC/local interpretation.
- Output
- ISO-style dates, local display, and Unix second or millisecond values.
- Real limitations
- Time-zone and daylight-saving interpretation depends on the browser; leap seconds are not represented by standard Unix time.
- Privacy and data handling
- an epoch value or calendar date, precision, and UTC/local interpretation is processed in this browser tab. Convertr does not receive or store it; closing or reloading the page clears the working state unless the tool explicitly offers a local download.
How to use this tool
- Provide an epoch value or calendar date, precision, and UTC/local interpretation in the tool controls.
- Choose the settings that affect ISO-style dates, local display, and Unix second or millisecond values, then run the tool.
- Review ISO-style dates, local display, and Unix second or millisecond values before copying or downloading it.
Common failure modes
An out-of-range timestamp, invalid calendar date, or mistaken seconds-versus-milliseconds choice produces an error or unexpected year.
Useful example
Convert 0 seconds to 1970-01-01T00:00:00Z, then convert a chosen UTC date back to seconds.