Data & APIs
Timestamp converter
Unix timestamp to date converter: UTC ISO, local time, seconds, and milliseconds—instantly.
Overview
Paste an epoch value or a string `Date.parse` understands to see synchronized outputs. Short numeric strings (<10 digits) default to seconds while longer values default to milliseconds—use the toggles when APIs disagree. Handy for JWT `exp`, log correlation, and API debugging next to the JSON formatter.
Plain numbers: under 10 digits are treated as seconds; 10+ digits as milliseconds. Override with the toggles when needed.
Frequently asked questions
How does this Unix timestamp converter tell seconds apart from milliseconds?
By default, integers with fewer than 10 absolute digits are multiplied by 1000; longer integers are treated as milliseconds. Check a toggle to force either interpretation.
What time zone is the ISO 8601 output—UTC or local?
`toISOString` is always UTC with a trailing Z. The “Local string” card shows the browser zone.
Why does my date string or epoch value fail to parse?
The value must parse in the current browser. Sticky formats may need zero-padding or an explicit offset.
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