Unix timestamp converter
Turn a Unix timestamp into a readable date, or a date into a timestamp — with the current epoch time ticking live. Handy when you are reading logs, a database column or an API response.
–––Timestamp → date
Date → timestamp
The classic mix-up: seconds and milliseconds swapped
Nearly every timestamp bug in the wild is the same bug wearing two costumes. Feed a seconds value into code expecting milliseconds and every date collapses to January 1970 — the number is a thousand times too small, so the clock barely moves past the epoch. Feed milliseconds into code expecting seconds and dates leap tens of thousands of years into the future. Both symptoms are instantly recognisable once you know the tell: today's time in seconds is a ten-digit number, in milliseconds thirteen digits. The auto-detect here reads that difference for you, but knowing it by eye lets you spot the bug in your own logs before you have converted anything at all.
Timestamps in the wild
Once you start noticing them, epoch times are everywhere: created_at columns in databases, expiry fields in cookies and cache headers, event times in server logs, and the exp claim inside every JSON Web Token. The last one is a genuinely useful pairing — decode a token with the JWT decoder, paste its exp number in here, and the relative line tells you in plain words whether the token died an hour ago or lives for another week. That relative phrase is quietly the best sanity check on the page: a session that claims to expire in forty-six years is a bug you can smell without doing any arithmetic.
Edges of the epoch
A few corners are worth knowing. Negative timestamps are legitimate — they count backwards from 1970, so historic dates convert fine here. The year 2038 is the famous cliff for old systems that store seconds in a 32-bit integer, which overflows in January of that year; modern 64-bit systems shrugged this off long ago, but the date still matters if you maintain anything embedded or ancient. And Unix time deliberately ignores leap seconds — every day is exactly 86,400 seconds as far as the epoch is concerned, which is precisely what makes the arithmetic dependable. All of it runs in your browser, free and without limits, like the rest of the developer tools here.
What a Unix timestamp is
A Unix timestamp (or "epoch time") is simply the number of seconds that have passed since midnight UTC on 1 January 1970. It is how computers store a moment in time without worrying about time zones or calendar formatting, which is why you meet it constantly in logs, databases, cookies and API responses. Some systems count in milliseconds instead of seconds — a thousand times bigger — so this tool detects which one you pasted and converts it correctly. Everything runs in your browser; nothing you type is sent anywhere.
Seconds or milliseconds — how does it know?
In "Auto-detect" mode it assumes seconds for normal-length numbers and milliseconds for very large ones (13+ digits), which is right almost every time. If a value is ambiguous, switch the unit dropdown to force seconds or milliseconds.
Why do UTC and my local time differ?
A timestamp is a single moment; UTC and your local time are two ways of writing that same moment. The tool shows both, labelled with your browser's time zone, so you can pick whichever you need.
Can I go from a date to a timestamp?
Yes — use the "Date → timestamp" box. Pick a date and time (read in your local time zone) and you get the Unix timestamp in both seconds and milliseconds, plus the ISO 8601 form in UTC.
What is ISO 8601?
ISO 8601 is the standard text format for a date and time, like 2026-07-20T14:30:00.000Z — unambiguous and sortable. The trailing "Z" means UTC. It is the safest way to write a timestamp for humans and machines alike.
Is anything sent to a server?
No. All the conversion happens in your browser with JavaScript — you could disconnect from the internet and it would still work. Nothing is uploaded or logged.
