Timestamp Converter
Convert Unix seconds, milliseconds, or date strings into readable UTC and local dates.
About Timestamp Converter
Unix timestamps count time from 1970-01-01T00:00:00Z. APIs and logs commonly report seconds or milliseconds, and confusing the two scales can move a date thousands of years away from its intended value.
Enter a 10-digit seconds value, a 13-digit milliseconds value, or a date string understood by the browser. The output includes UTC and local representations; local display depends on the device time zone, so use the ISO or UTC value when sharing an unambiguous date.
How to use this tool
Enter a Unix timestamp or an ISO-style date string. The converter detects seconds versus milliseconds by digit length and displays both UTC and device-local time.
Frequently asked questions
How does the converter distinguish seconds from milliseconds?
Integer timestamps with up to 10 digits (excluding a leading minus sign) are treated as seconds; longer integer values are treated as milliseconds.
Why does local time differ from UTC?
Local display uses the time zone configured on your device and may include a daylight-saving offset. ISO and UTC output provide an unambiguous reference.
Which date string formats are supported?
The browser Date parser handles common date strings. ISO 8601 strings with an explicit Z or numeric offset are recommended for predictable results.
Related Tools
JSON Formatter
Format, validate, and minify JSON data with syntax highlighting and error detection.
JWT Decoder
Decode and inspect JSON Web Tokens. View header, payload, and expiration info.
UUID Generator
Generate cryptographically secure UUID v4 values. Single or bulk generation.