Paste a Unix timestamp (seconds or milliseconds) or a date string, then click Convert Timestamp. The result renders below - nothing leaves your browser.
Unix Timestamp Converter
Paste a Unix timestamp and read it as a normal date, or paste a date and get the Unix seconds and milliseconds back. The conversion is plain JavaScript running in your browser - nothing is sent to a server.
Key features
- Auto-detects the unit from the digit count - seconds, milliseconds, microseconds, or nanoseconds - so you never choose a mode first.
- Shows the same instant several ways at once: ISO 8601 UTC, your local time with its UTC offset, and a relative phrase such as "3 days ago" - quick to sanity-check a log entry, an API response field, or a database row against wall-clock time.
- Shows a plain-language hint with working examples instead of an error dump when the input is not a timestamp or a date.
- Copy Output button puts the formatted result on your clipboard for pasting into a ticket or a query.
How the Unix Timestamp Converter tells seconds from milliseconds
The Unix Timestamp Converter reads the digit count of whatever you paste to pick the unit before doing any math, instead of asking you to choose a mode first. A value up to 11 digits is treated as seconds - the current epoch sits at 10 digits, so this range covers every real-world second-based timestamp with headroom. A value of 12 to 14 digits is read as milliseconds - JavaScript's own Date.now() output lands at 13 digits today. A value of 15 to 17 digits is read as microseconds, and 18 digits or more is read as nanoseconds, the two formats you are more likely to meet in a database export or a tracing tool than in everyday application code.
| Digits | Unit detected | Example |
|---|---|---|
| Up to 11 | Seconds | 1756800000 |
| 12-14 | Milliseconds | 1756800000000 |
| 15-17 | Microseconds | 1756800000000000 |
| 18+ | Nanoseconds | 1756800000000000000 |
Getting the unit wrong is not a small rounding error - it is the classic off-by-1000 mistake where a millisecond value read as seconds lands in the year 1970, and a seconds value read as milliseconds lands tens of thousands of years in the future. Detecting the unit from digit count, rather than from a dropdown, means pasting a value straight from a system log (typically seconds) or straight from a JavaScript Date.now() call or browser event timestamp (typically milliseconds) into the same box always resolves correctly without you needing to know which one it is first.
Convert a date back to a Unix timestamp
The reverse direction uses the same no-mode-switch approach: paste a date instead of a number - an ISO 8601 string such as 2026-09-02T12:00:00Z, or any other format the browser's own date parser can read - and the Unix Timestamp Converter returns both values for that instant side by side. For example, pasting 2026-09-02T12:00:00Z returns Unix seconds 1788350400 and Unix milliseconds 1788350400000 together, so you never have to remember which unit a downstream system expects before pasting the result back in.
Frequently Asked Questions
What does this Unix timestamp converter do?
It converts a pasted Unix timestamp into a readable date, and also works the other way: paste a date such as 2026-09-02T12:00:00Z and it returns the Unix seconds and milliseconds. Everything runs as plain JavaScript in your browser - nothing is sent to a server.
Do I have to say whether my timestamp is in seconds or milliseconds?
No. The unit is detected from the digit count: about 10 digits is read as seconds, 13 as milliseconds, and longer microsecond or nanosecond values from database exports are recognized the same way.
What formats does the output show?
The same instant is shown several ways at once: ISO 8601 UTC, your local time with its UTC offset, an RFC-style UTC string, and a relative phrase such as "3 days ago". A Copy Output button puts the whole result on your clipboard.
What happens if I paste something that is not a timestamp?
The page shows a plain-language hint with working examples - a 10-digit seconds value, a 13-digit milliseconds value, or an ISO date - instead of throwing an error.
Does this converter store or track what I paste?
No. Nothing you paste is stored beyond the current page session, sent to any analytics or tracking service, or tied to an account - there is nothing to sign up for. The conversion runs as plain JavaScript in your browser, so your timestamp or date never leaves the tab.