Z

Unix Timestamp Converter

Convert Unix timestamps (seconds or milliseconds) to ISO, UTC, RFC 2822, local, and relative formats. Live "Now" panel.

Free No signup Client-side Privacy friendly

Auto-detects seconds vs milliseconds. ISO 8601 strings also accepted.

Converted

Invalid input.

Now (live)

How to use

  1. 1 Paste a Unix timestamp (seconds or milliseconds) or any ISO 8601 / RFC 2822 date string into the input.
  2. 2 The Converted panel shows the date in every common form, including a relative phrase like "3 days ago".
  3. 3 The Now panel refreshes every second so you can grab the current Unix time at a glance.
  4. 4 Use Copy on any row to push it to your clipboard.

Why use this tool

  • Auto-detects seconds vs milliseconds — no more accidentally dividing by 1000.
  • Shows ISO, local, UTC, RFC 2822, and a relative form in one view.
  • Live "Now" reference, useful when you need to script the current timestamp.
  • Runs in your browser — no clock skew from a server.

Frequently asked questions

How does it tell seconds from milliseconds?

Any input ≥ 1e11 is treated as milliseconds. That threshold corresponds to year ~5138 in seconds, but only March 1973 in milliseconds — so it correctly classifies every real-world timestamp.

What does "negative timestamp" mean?

Unix timestamps before 1970-01-01 UTC are negative. The tool handles them — try -2208988800 for 1900-01-01.

Need this value in a different timezone?

Use our Timezone Converter — paste the ISO output, then pick source and target zones.

How do I add hours to this timestamp?

Convert it to ISO, then use the Date Calculator in Add mode for calendar arithmetic.

Summary

Unix Timestamp Converter is a free developer utility by Zerethon Tools. Convert Unix timestamps (seconds or milliseconds) to ISO, UTC, RFC 2822, local, and relative formats. Live "Now" panel. Runs entirely in the browser — no signup, no upload.

Category
Developer
Pricing
Free
Privacy
Browser-based
Signup
Not required

Privacy

Your data never leaves your browser unless explicitly stated. Unix Timestamp Converter runs entirely client-side — no server upload, no logging, no tracking of your input.

Related tools

JSON Formatter

Format, validate, and minify JSON online. Free, no signup — your data never leaves your browser.

Open tool

SQL Formatter

Format SQL queries online — beautify MySQL, PostgreSQL, SQLite, SQL Server, Oracle, and BigQuery.

Open tool

UUID Generator

Generate UUIDs online — v1, v4, v7, and Nil. Bulk generation up to 10,000. Free, no signup.

Open tool

Password Generator

Generate strong, cryptographically random passwords. Configurable length and character sets — runs in your browser.

Open tool

Build, share, and grow on Zerethon Social

Free signup. Earn points, collect achievements, and connect with creators worldwide.

Try Zerethon free