Unix Timestamp Converter
Convert Unix timestamps to readable dates and back — free, no signup, live clock included.
Timezone scope: this tool shows UTC and your browser's local timezone only. It does not convert to other named timezones.
What Is the Unix Timestamp Converter?
A unix timestamp converter is a tool that translates between Unix time — the number of seconds (or milliseconds) since 1 January 1970 — and a readable date and time. Paste a timestamp and this converter shows the date in UTC, in your local timezone, in ISO format, and as a relative time like "3 hours ago", or go the other way and turn a date into a timestamp.
What Is It Used For?
Developers use it to read timestamps from logs, databases, and APIs, which almost always store time as a plain number. Support staff use it to turn a customer's timestamp into a real date. Data workers use it to check expiry times, scheduled jobs, and event times. Students learning programming use it to understand how computers store time.
Key Benefits
- Live clock — the current Unix time in seconds updates every second at the top of the page.
- Seconds or milliseconds, auto-detected — paste either form; the tool works out which one it is.
- Four views at once — UTC, your local time, ISO 8601, and relative time, side by side.
- Both directions — timestamp to date, and date to timestamp.
- Batch mode — convert a whole list of timestamps, one per line, in one click.
- Copy buttons — copy the ISO or UTC result straight into code, tickets, or messages.
- Completely free and private — no signup, and everything runs in your browser.
How to Use This Unix Timestamp Converter
- To read a timestamp: paste it into the timestamp box (seconds or milliseconds) and click Convert. Read the UTC, local, ISO, and relative results below.
- To use the current moment: click Use Current Time, which fills the box with the live timestamp.
- To go the other way: pick a date and a time, then click Convert Date to Timestamp. The date is read in your browser's local timezone.
- For many values at once: paste one timestamp per line into the batch box and click Convert Batch.
Common Mistakes to Avoid With Unix Timestamps
- Mixing up seconds and milliseconds. A 13-digit number is milliseconds; a 10-digit number is seconds. Converting one as the other lands you centuries off — this tool auto-detects, but always sanity-check the year.
- Forgetting the timezone. The same timestamp is a different clock time in every timezone. Always say whether you mean UTC or local time when sharing a converted date.
- Reading a date input as UTC. Date and time inputs on this page are read in your browser's local timezone, not UTC, so the same wall-clock time gives a different timestamp in another timezone.
- Assuming every timestamp is in seconds. JavaScript's Date.now() returns milliseconds, while many APIs return seconds — check the digit count before converting.
- Trusting relative time for exact work. "3 hours ago" is a friendly summary, not a precise value — use the ISO or UTC output when exactness matters.
Frequently Asked Questions
Is this timestamp converter free? Yes, completely free — no signup, no download, no limits.
Is anything I enter uploaded anywhere? No. Conversion happens entirely in your browser, so your timestamps and dates never leave your device.
What is a Unix timestamp? The number of seconds since 00:00:00 UTC on 1 January 1970 (the Unix epoch), not counting leap seconds. It is how most systems store a point in time as a single number.
How does auto-detection work? Values with an absolute size of 1,000,000,000,000 or more are treated as milliseconds; smaller values are treated as seconds. A 10-digit value is seconds, a 13-digit value is milliseconds.
What timezones does it show? UTC and your browser's local timezone only. It does not convert to other named timezones such as Tokyo or New York unless that happens to be your local timezone.
Why do UTC and local time differ? Because your local timezone is offset from UTC. The timestamp itself is one instant; the clock reading depends on where you are.
What is the ISO format? A standard written form like 2026-10-31T12:00:00.000Z, where Z means UTC. It is unambiguous across systems and is the safest form to paste into code or tickets.
How is relative time calculated? By comparing the converted date with the current moment in your browser: seconds, minutes, hours, or days ago, or "in" that time for future dates.
Can it convert negative timestamps? Yes. Negative values are dates before 1970, and the tool converts them the same way.
Does batch mode handle mixed seconds and milliseconds? Yes. Each line is auto-detected separately, and any line that is not a number is reported as invalid in the results.
Does the live clock update? Yes, every second, showing the current Unix time in seconds.
Can I convert a date in a different timezone? Not directly. The date inputs are read in your local timezone. To convert a time from another timezone, first work out what it is in your local time or in UTC.
Does it work on mobile? Yes. The tool runs in any modern mobile browser and the layout adjusts to small screens.
Final Thoughts
Timestamps look meaningless until you can read them as dates — and then they answer the question behind every log line and API response: when exactly did this happen? Keep this converter bookmarked and paste first, guess never.