About this tool

Unix Timestamp Converter

Convert Unix timestamps to readable local, UTC, and ISO dates.

The Unix Timestamp Converter turns an epoch value — seconds or milliseconds since 1970-01-01 00:00:00 UTC — into six readable forms at once: seconds, milliseconds, your local time, the UTC string, ISO 8601, and your current UTC offset in minutes. It detects the unit automatically, treating any value longer than 10 digits as milliseconds and anything shorter as seconds, so you can paste a log value without stopping to count zeros. The conversion runs both ways: pick a date and time and it gives you back the epoch seconds to copy.

How to use Unix Timestamp Converter

1. 1

   Open Unix Timestamp Converter on AltFTool — it loads instantly in your browser.

2. 2

   Paste the value into the Unix timestamp field — anything longer than 10 digits is read as milliseconds and anything shorter as seconds — or press Now to load the current instant.

3. 3

   To go the other way, pick a moment in the Date and time picker; it writes the matching epoch seconds straight back into the timestamp field.

4. 4

   The panel shows Seconds, Milliseconds, Local time, UTC time, ISO 8601 and Timezone offset in minutes side by side; Copy seconds puts the integer on the clipboard.

Why use Unix Timestamp Converter

• Seconds and milliseconds auto-detected

  Values over 10 digits are read as milliseconds, so a Java or JavaScript timestamp and a Unix seconds value both resolve correctly without a unit switch.

• Local, UTC and ISO side by side

  All three renderings are shown at once, which is what you need when the bug is precisely that two systems disagree about the timezone.

• Converts in both directions

  The date-and-time picker writes back to the timestamp field, so you can go from a calendar date to an epoch value as easily as the reverse.

Common use cases

• A log line or a JSON payload contains created_at: 1767225600 and you need to know what moment that actually was in your own timezone before replying to the incident.
• You are writing a database query or a test fixture that needs an exact epoch value for a specific date, and you want the seconds figure without doing the arithmetic.
• Two systems disagree about when an event happened and you suspect one is reporting milliseconds while the other reports seconds, so you convert both and compare.

Frequently asked questions