Timestamp Converter — Unix, ISO 8601 & Human-Readable

Convert between Unix timestamps, ISO 8601, and human-readable date formats.

How It Works

  1. 1Paste a Unix timestamp or pick a date and time.
  2. 2The other format updates automatically across multiple time zones.
  3. 3Copy any value with one click.

About Timestamp Converter

Working with timestamps in different formats is a daily task for developers, data engineers, and system administrators. Unix timestamps (seconds since January 1, 1970), ISO 8601 strings, and human-readable dates are all common in APIs, databases, log files, and configuration systems, but converting between them manually is tedious and error-prone. This tool converts seamlessly between Unix timestamps in seconds, Unix timestamps in milliseconds (used by JavaScript and Java), ISO 8601 strings (the standard for API communication), and human-readable date/time formats. Enter any format and instantly see all the others. Use the 'Now' button to capture the current timestamp for quick reference. Select a timezone from the dropdown to see how the same moment in time is represented across different time zones — invaluable when debugging issues across globally distributed systems. Common use cases include decoding timestamps from API responses, converting log file timestamps for incident analysis, generating timestamps for database queries, and verifying token expiration times.

From the blog

Frequently Asked Questions

What timezone is used?

Unix timestamps are timezone-independent (they represent seconds since 1970-01-01 UTC). The human-readable output uses your browser's local timezone.

What's the difference between seconds and milliseconds?

Unix timestamps in seconds are 10 digits (e.g., 1700000000). Milliseconds are 13 digits (e.g., 1700000000000). JavaScript's Date.now() returns milliseconds.

What is ISO 8601 and when should I use it?

ISO 8601 is the international standard for representing dates and times as a string, like 2026-05-03T14:30:00Z. Use it whenever a date crosses a system or API boundary — it removes any ambiguity about format or time zone.

Is my file uploaded to a server?

No. Transmute processes everything locally in your browser using JavaScript and the Canvas API. Your files never leave your device — there is no server, no upload, no cloud processing.

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