What is a Unix timestamp?

It’s the number of seconds elapsed since 1 January 1970, 00:00:00 UTC — the “Unix epoch”. It’s the standard way computers store points in time: a single number, no timezones, no formats. 0 means the epoch itself; 1753238400 is a date in 2025.

How do I tell seconds from milliseconds?

By length: current dates are 10 digits in seconds (1.7 billion-ish) and 13 digits in milliseconds. JavaScript’s Date.now() gives milliseconds; most APIs and databases use seconds. This tool auto-detects which one you pasted and says so — a factor-of-1000 mistake puts you 50,000 years off.

Are Unix timestamps affected by timezones?

No — that’s their superpower. A timestamp is the same number everywhere on Earth; only its rendering as local time differs. This tool shows the converted moment in your local timezone, in UTC, and in ISO 8601 so you can see all three at once.

Does the conversion happen on a server?

No — everything runs in your browser, including the live “current timestamp” ticker. Nothing you paste is transmitted or stored, and the tool works offline once loaded.

What is the year 2038 problem?

Old systems store timestamps as signed 32-bit integers, which overflow on 19 January 2038 at 03:14:07 UTC. Modern software uses 64-bit values and is fine for billions of years. If you maintain legacy embedded systems or old databases, it’s a real migration item.

Can timestamps be negative?

Yes — negative values count backwards from 1970. For example, -86400 is 31 December 1969. Dates before 1970 are routinely stored this way, and this converter handles them.

What’s the ISO 8601 output for?

ISO 8601 (like 2025-07-23T04:30:00.000Z) is the standard human-readable, machine-parseable date format — unambiguous about ordering and timezone. It’s what you want in logs, APIs and config files; the copy button gives it to you exactly as JavaScript, Python and databases expect.

Unix Timestamp Converter

Convert Unix timestamps to human dates and back — auto-detects seconds vs milliseconds, shows local, UTC and ISO 8601.

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Current Unix timestamp: 1,78,47,98,674

23/7/2026, 2:54:34 pm · updates every second

Direction

Unix timestamp (seconds or milliseconds)

Convert Unix timestamps to dates — and back — without off-by-1000 mistakes

Logs, APIs, databases and JWT claims all speak in Unix timestamps — seconds since 1 January 1970 UTC. Humans don’t. Paste any timestamp above and get the moment it represents inyour local timezone, in UTC, and in ISO 8601, plus a plain-English “3 days ago”. Or flip direction: pick a date and time and get the epoch seconds and milliseconds to paste into your code.

Auto-detects seconds vs milliseconds

The classic timestamp bug is a factor of 1000: JavaScript uses milliseconds, most back-ends use seconds, and mixing them lands you in the year 57644. This converter detects which unit you pasted from the digit count, tells you what it assumed, and converts accordingly — no more mystery dates.

A live epoch clock, running locally

The current Unix timestamp ticks at the top of the tool, generated by your own device’s clock — handy for writing test data or checking clock drift. Like everything on this page, it involvesno server: nothing you paste is transmitted or stored, and the tool works offline.

Where you’ll use it

Reading exp and iat claims from a token you inspected in theJWT decoder. Making sense of created_at fields in API responses you cleaned up with the JSON formatter. Generating unique test records with IDs from the UUID generator and realistic time fields from here.

Frequently Asked Questions

What is a Unix timestamp?
It’s the number of seconds elapsed since 1 January 1970, 00:00:00 UTC — the “Unix epoch”. It’s the standard way computers store points in time: a single number, no timezones, no formats. 0 means the epoch itself; 1753238400 is a date in 2025.
How do I tell seconds from milliseconds?
By length: current dates are 10 digits in seconds (1.7 billion-ish) and 13 digits in milliseconds. JavaScript’s Date.now() gives milliseconds; most APIs and databases use seconds. This tool auto-detects which one you pasted and says so — a factor-of-1000 mistake puts you 50,000 years off.
Are Unix timestamps affected by timezones?
No — that’s their superpower. A timestamp is the same number everywhere on Earth; only its rendering as local time differs. This tool shows the converted moment in your local timezone, in UTC, and in ISO 8601 so you can see all three at once.
Does the conversion happen on a server?
No — everything runs in your browser, including the live “current timestamp” ticker. Nothing you paste is transmitted or stored, and the tool works offline once loaded.
What is the year 2038 problem?
Old systems store timestamps as signed 32-bit integers, which overflow on 19 January 2038 at 03:14:07 UTC. Modern software uses 64-bit values and is fine for billions of years. If you maintain legacy embedded systems or old databases, it’s a real migration item.
Can timestamps be negative?
Yes — negative values count backwards from 1970. For example, -86400 is 31 December 1969. Dates before 1970 are routinely stored this way, and this converter handles them.
What’s the ISO 8601 output for?
ISO 8601 (like 2025-07-23T04:30:00.000Z) is the standard human-readable, machine-parseable date format — unambiguous about ordering and timezone. It’s what you want in logs, APIs and config files; the copy button gives it to you exactly as JavaScript, Python and databases expect.