Unix Timestamp Converter — Epoch to Date, No Upload
Convert a Unix timestamp (epoch) to a human-readable UTC and local date — or go the other way. Auto-detects seconds vs milliseconds. Everything runs in your browser with no upload, no account, no logs.
How to use this tool
- Enter a Unix timestamp or a human-readable date.
- See instant conversion between Unix and ISO 8601 formats.
- Copy the result in your preferred format.
About Unix Timestamp Converter
The Unix timestamp converter translates an epoch timestamp into a human-readable date and time, and it does so two ways at once. Paste or type a numeric timestamp and the tool shows both the UTC value in full ISO 8601 form, such as a year-month-day string ending in Z, and your local time as rendered by your own browser and operating system. A copy button sits beside each output so you can grab whichever representation you need.
A Unix timestamp counts from the epoch of January 1, 1970 at midnight UTC, but it can be expressed in either seconds or milliseconds, and mixing the two is a common source of bugs. The converter auto-detects the unit by digit count: roughly ten digits is interpreted as seconds and thirteen as milliseconds. If the guess is ever wrong, a toggle lets you force the unit manually. Input is parsed leniently, stripping non-digit characters, and a use-now button fills in the current timestamp so you can sanity-check the format quickly.
This is a developer and operations staple. Logs, databases, JWT expiry claims, API responses, and event streams routinely store times as epoch integers, and reading them at a glance is awkward. The converter is the fast way to answer questions like what real-world moment a log line corresponds to, or whether a token's expiry is in the past. Because it prints both UTC and local time, it also helps when you need to reconcile a server timestamp recorded in UTC against what a user in your own zone would have seen.
The conversion is built on JavaScript's native Date object, so it inherits that object's behaviour: it accepts negative timestamps for dates before 1970, and its reliable range covers the years from 1 through roughly 4000, well beyond any realistic log data. The local time is shown in the default Date string format and cannot be reformatted into a custom locale or pattern, and invalid or out-of-range input simply yields no result rather than an error. All of this runs locally in your browser, so the timestamps you paste never leave your device.
Frequently Asked Questions
- Does it work with seconds or milliseconds?
- Both. The tool auto-detects the unit from the number of digits, treating about ten digits as seconds and thirteen as milliseconds, which covers the common cases. If a particular value is ambiguous or detected incorrectly, you can override the choice with the seconds-versus-milliseconds toggle at any time.
- Which time zone does the output use?
- It shows two values side by side. One is UTC in ISO 8601 format, ending in a Z to mark it as universal time, and the other is your browser's local time, computed from your system's time zone settings. Showing both lets you reconcile a server timestamp stored in UTC against what a local user would see.
- What is the epoch the timestamps are measured from?
- Unix timestamps count the time elapsed since the epoch, midnight UTC on January 1, 1970. A value of zero is that exact instant, positive values are afterwards, and negative values are before it. The converter accepts negative timestamps, so dates earlier than 1970 are supported.
- What is the use-now button for?
- It fills the input with the current timestamp from your system clock. That is handy for confirming the expected digit length and unit, comparing a stored timestamp against right now to see if it is in the past or future, or simply generating a fresh epoch value to copy.
- What range of dates can it handle?
- Because it uses JavaScript's built-in Date object, it reliably covers roughly the years 1 through 4000, which spans any realistic log, database, or token value. Inputs that fall outside the valid range, or that are not a parseable number, simply produce no result rather than throwing an error.
- Can I change how the date is formatted?
- Not for the local time display, which uses the browser's standard Date string format and cannot be switched to a custom locale or pattern. The UTC output is fixed to ISO 8601. Both formats are copy-friendly and unambiguous, which is what most debugging and integration work needs.
- Is my timestamp sent anywhere?
- No. The conversion is done in your browser with native date functions, so the timestamps you paste in are processed locally and never transmitted to a server.
Embed this tool on your site
Free. One line of HTML — the tool runs in your visitor's browser, no data sent to anyone.
<iframe src="https://brevio.pro/embed/timestamp-converter" width="100%" height="600" loading="lazy" style="border:1px solid #e5e5e5;border-radius:8px" title="Unix Timestamp Converter — brevio"></iframe> <p style="font:12px/1.4 sans-serif"><a href="https://brevio.pro/tools/timestamp-converter">Unix Timestamp Converter</a> by <a href="https://brevio.pro">brevio</a></p>