Corvo

Converters

Unix Timestamp Converter

Convert Unix timestamps to human-readable dates and back, in both UTC and your local time. Auto-detects seconds vs. milliseconds. Free, instant, entirely in your browser.

Runs entirely in your browser. Nothing is uploaded.

ISO 8601 Waiting for input
UTC Waiting for input
Local time Waiting for input
Relative Waiting for input
Unix (seconds) Waiting for input
Unix (ms) Waiting for input
Waiting for input

What this tool does

Converts between a Unix timestamp and a human-readable date, in both directions, live — edit either field and the other updates automatically, along with ISO 8601, UTC, local time, and a relative "3 hours ago" style reading, all computed at once.

How to use it

  1. Type a Unix timestamp on the left, or pick a date and time on the right — editing either one updates everything else.
  2. Press Use current time to jump straight to right now.
  3. If a timestamp's seconds-vs-milliseconds guess looks wrong, set the unit manually.
  4. Copy any of the derived formats with its own Copy button.

Seconds or milliseconds?

Both are common — Unix systems and most APIs traditionally use seconds, while JavaScript's own Date.now() and many web APIs use milliseconds. This tool guesses based on how many digits the number has (seconds-since-epoch stays under 11 digits until the year 5138, milliseconds hits 13 digits much sooner), which correctly handles the overwhelming majority of real timestamps without you needing to think about it — but the unit selector is there for the rare case the guess is wrong.

Why UTC and local time both matter

A Unix timestamp has no timezone of its own — it's a count of seconds since a fixed moment, identical everywhere on Earth. UTC is what you'll see in most server logs, databases, and API responses, since storing an unambiguous timezone-free reference avoids an entire category of bugs. Local time is what that same instant looks like on your own clock right now — useful for sanity-checking a timestamp against "did this happen this morning or last night for me."

Questions

Is this Timestamp Converter free?

Yes, completely, with no signup and no limit on how much you convert.

Is anything sent to a server?

No. Every conversion happens in your browser using JavaScript's own date handling — nothing is transmitted anywhere.

How does it know if my timestamp is in seconds or milliseconds?

By its size. A Unix timestamp in seconds stays under 11 digits until the year 5138; the same moment in milliseconds is 13 digits. Anything at or above that threshold is treated as milliseconds. If you have an unusual value the guess gets wrong, switch the unit selector manually.

What is a Unix timestamp, exactly?

The number of seconds (or milliseconds, depending on the system) that have passed since midnight UTC on 1 January 1970 — the "Unix epoch." It's a single number that unambiguously represents a moment in time, which is why so many systems use it internally instead of a formatted date string.

Why does it show both a UTC time and a local time?

Because a Unix timestamp itself has no timezone — it's the same number everywhere on Earth for a given moment. Showing both makes clear which one you're looking at: UTC is what most systems log and store, while your local time is what that same moment looks like on your own clock right now.

Can it handle dates before 1970?

Yes — Unix timestamps can be negative to represent moments before the epoch, and this tool handles that correctly in both directions.

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