Unix Timestamp Converter
Convert Unix timestamps to ISO 8601, UTC, local, RFC 2822 and 16 timezones — with a live ticking clock, auto seconds/ms detection and copy-to-clipboard on every value. Free, private, browser-only.
What is the Unix Timestamp Converter?
A Unix Timestamp Converter turns the number of seconds (or milliseconds) since the Unix epoch (1 Jan 1970 UTC) into a human-readable date — and back. Toollyz Unix Timestamp Converter shows a live ticking clock with the current epoch in both seconds and milliseconds plus the ISO 8601 and UTC strings, then lets you paste any timestamp (seconds, milliseconds or a relaxed ISO/RFC date string) and see it expressed in twelve formats at once: epoch seconds, epoch milliseconds, ISO 8601, UTC (`Date.toUTCString`), local long, local short, UTC readable, RFC 2822, date-only, time-only, weekday + month + day-of-year + ISO week, and a relative phrase (`in 3 minutes`, `2 hours ago`) computed by `Intl.RelativeTimeFormat`. Switch to the Timezones tab to see the same moment in sixteen popular zones (UTC, America/Los_Angeles, America/New_York, Europe/London, Europe/Berlin, Asia/Dubai, Asia/Kolkata, Asia/Tokyo, Australia/Sydney and more) — every formatter respects your browser's built-in IANA tz database, so leap-seconds and DST transitions match the OS. Every value has a one-click copy button. Auto-detect treats 10-digit and shorter integers as seconds and 13-digit positive integers as milliseconds.
How to use it
- Watch the live hero for the current epoch and ISO time, ticking once per second.
- Paste any timestamp or date into the input — choose Auto / Seconds / Milliseconds for numeric input.
- Read off the formats panel; click the copy icon on any value to grab it.
- Switch to Timezones to see the same instant in 16 popular zones.
Benefits
- Live ticking clock with the current epoch in seconds, milliseconds, ISO 8601 and UTC.
- Auto-detection between seconds and milliseconds based on integer length.
- Twelve output formats including ISO, UTC, local, RFC 2822, date-only, time-only and ISO week.
- Relative time formatting via `Intl.RelativeTimeFormat` for natural-language deltas.
- 16 common IANA timezones in a dedicated tab, formatted with `Intl.DateTimeFormat`.
- One-click copy on every value.
- Accepts relaxed date strings via `Date.parse` (most ISO 8601 and RFC 2822 work).
- 100% private — Toollyz has no backend, draft saved to localStorage.
Frequently asked questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have elapsed since 00:00:00 UTC on Thursday, 1 January 1970, the so-called Unix epoch. Many APIs, log files and databases store time as an epoch integer because it's compact, unambiguous and easy to compare.
How do I know if my number is seconds or milliseconds?
Seconds are 10 digits or fewer through year 2286; milliseconds are 13 digits today. Toollyz auto-detects: it treats 10-digit and shorter integers as seconds and 13-digit positive integers as milliseconds. You can override with the Unit selector.
What date formats does the input accept?
Numeric Unix timestamps (seconds or milliseconds), ISO 8601 (`2026-05-30T14:00:00Z`) and most RFC 2822 variants. Anything `Date.parse` understands works; if a string fails, you'll see an error in the input panel.
Where do the timezone names come from?
They're official IANA timezone identifiers (the `tz database`). Your browser's `Intl` API ships its own copy of the database; Toollyz simply asks it to format the date in each requested zone.
Does it handle daylight-saving time?
Yes — `Intl.DateTimeFormat` applies the correct DST offset for each timezone at the requested instant. If your OS's tz database is out of date, the displayed time may be off; install OS updates to fix.
What's the relative-time line?
It uses `Intl.RelativeTimeFormat` to express the difference between the parsed timestamp and the current moment as a natural-language phrase like "in 3 minutes" or "2 days ago". It updates as the clock ticks.
Does it work offline?
Yes — once the page is loaded, every conversion runs in your browser without any network call. The live clock updates each second from `Date.now`.
Is my input uploaded?
No. Toollyz has no backend. Your current input is saved to localStorage so a refresh doesn't lose it, but nothing is sent to a server.
What is ISO week and day-of-year?
ISO week is the 1–53 week number per ISO 8601 (week starting Monday; the week containing 4 Jan is week 1). Day-of-year is 1–366. Both are useful for project planning and astronomy.
Is this Unix Timestamp Converter free?
Completely free with no signup and no limits. Convert as many timestamps as you like — privately in your browser.