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Epoch Converter

Convert Unix timestamps to human dates and back. Millisecond stamps are detected automatically, and everything runs in this browser tab.

Current Unix epoch time

ticking every second, from your device clock

…

ms …

Timestamp to date

Seconds or milliseconds — 13-digit values are treated as ms automatically.

Paste or type a timestamp to see the full date breakdown.

Date to timestamp

Accepts dates and ISO 8601 datetimes, with Z or ±HH:MM offsets. No offset means your local time.

Type a date to get its timestamp in seconds and milliseconds.

Quick Answer

The epoch converter at practicalwebtools.com/dev-tools/web/epoch-converter converts Unix timestamps to readable dates and back, in seconds or milliseconds — 13-digit values are detected as milliseconds automatically. It shows local time, UTC, ISO 8601, weekday, day of year, ISO week, and a relative phrase like "3 days ago", plus a live ticking epoch clock. It runs entirely in your browser tab.

How It Works

1

Paste a Unix timestamp — seconds or milliseconds, detected automatically from the digit count

2

Read the instant as local time, UTC, ISO 8601, weekday, day of year, ISO week, and relative time

3

Or type a date or ISO 8601 datetime to get its epoch seconds and milliseconds

4

Copy any value with its Copy button, or grab the live epoch from the ticking clock

Key Facts

  • Two-way conversion: epoch to local/UTC date, and date or ISO 8601 back to epoch seconds and milliseconds
  • Auto-detects units: 13-digit values (1e12 and up) are read as milliseconds, shorter ones as seconds
  • Live epoch clock ticks every second from your device clock, with one-tap copy
  • Full date breakdown: weekday, day of year, ISO 8601 week number, and relative time like "3 days ago"
  • Accepts ISO 8601 input with Z or ±HH:MM offsets; no offset means your local time
  • Handles pre-1970 dates through negative timestamps
  • Copy buttons on every output value
  • Runs entirely in this browser tab — nothing you type is sent anywhere

Frequently Asked Questions

What is a Unix epoch timestamp?

A Unix timestamp counts the seconds elapsed since 00:00:00 UTC on 1 January 1970 (the "epoch"), not counting leap seconds. Because it is a plain count of seconds, it carries no time zone: 1762248000 refers to the same instant everywhere, and you convert to a local calendar date only for display.

How do I tell seconds from milliseconds in a timestamp?

Count the digits. Current second-based timestamps are 10 digits (they stay 10 digits until the year 2286), while millisecond stamps are 13 digits — a 13-digit value in seconds would be far in the future, so 13 digits can only mean milliseconds. This converter applies that rule automatically: values of 1e12 (a 1 followed by 12 zeros) and above are read as milliseconds.

Does daylight saving or my time zone change a timestamp?

No. A timestamp is an absolute instant, stored as a count of UTC seconds. Your time zone only affects the local calendar date shown next to it. That is why this tool displays local time and UTC side by side — the UTC row is the zone-independent truth.

Can this converter handle dates before 1970?

Yes. Dates before the epoch are represented as negative timestamps — for example, minus 86400 is one full day before the epoch, 31 December 1969. Both directions of this converter accept negative values.

Is anything I type sent to a server?

No. I built this converter to run entirely in this browser tab — the timestamp math, the unit detection, and the live clock all execute locally. You can watch the Network tab in your browser developer tools: no request carries your input.

What does the ISO 8601 output mean?

ISO 8601 is the international date-time format, for example 2026-11-04T10:40:00.000Z. The T separates date and time, and the trailing Z marks UTC (zero offset). The converter accepts ISO 8601 input too, including offsets like +02:00 in place of the Z.