Timestamp Converter
Logs, APIs and databases keep time as a Unix timestamp: a bare count of seconds (or milliseconds) since 1 January 1970 UTC. Humans keep time as dates. This converter translates both ways — paste a timestamp to get its ISO 8601 form and your local time, or pick a date to get its timestamp in seconds and milliseconds.
Timestamp → Date
Date → Timestamp
How to use it
- To decode: paste a Unix timestamp, press Convert, and read its ISO and local forms.
- To encode: pick a date and time, and read off the timestamps in seconds and milliseconds.
- Compare values in your logs against the live clock readout at the top of the tool.
Key facts
- Timestamp zero is midnight UTC on 1 January 1970 — the Unix epoch.
- Current-era timestamps are 10 digits in seconds and 13 in milliseconds; auto-detect switches at the trillion mark.
- The ISO result is always UTC (note the trailing Z); the "local" result uses your browser's timezone.
About this tool
Logs, APIs and databases keep time as a Unix timestamp: a bare count of seconds (or milliseconds) since 1 January 1970 UTC. Humans keep time as dates. This converter translates both ways — paste a timestamp to get its ISO 8601 form and your local time, or pick a date to get its timestamp in seconds and milliseconds.
The classic ten-versus-thirteen-digit confusion is handled for you: seconds and milliseconds are detected automatically from the size of the number, and a unit selector lets you override the guess when a value is ambiguous. A live readout of the current Unix time sits at the top for quick comparison against your logs.
Like every TextKit tool, the Timestamp Converter runs entirely on your device. There is no account, no upload and no record of the content you process — close the tab and everything is gone.
Frequently asked questions
Is my timestamp in seconds or milliseconds?
Count the digits: 10 means seconds, 13 means milliseconds for any date in the current era. The converter auto-detects from magnitude, and the unit dropdown lets you force the interpretation when it matters.
Why do the ISO and local results differ?
They describe the same instant. ISO is expressed in UTC; the local form is the same moment rendered in your browser's timezone. For comparing values across systems, the UTC form is the safe one.
What happens with negative timestamps?
They count backwards from the epoch, so they represent dates before 1970. The converter handles them the same way, in either unit.
Related tools
JSON Formatter & Validator
Pretty-print, minify and validate JSON, with the exact error location when it breaks.
~/tool/json-to-csvJSON to CSV Converter
Convert a JSON array of objects into a tidy CSV, header row and quoting included.
~/tool/base64-encode-decodeBase64 Encode / Decode
Encode text to Base64 or decode it back, with full Unicode support.