How To Guide

How to Convert Unix Timestamp Online — Free Epoch Time Converter

Convert Unix timestamps (epoch seconds or milliseconds) to human-readable dates and back. Supports any timezone, ISO 8601 output, and batch conversion.

What a Unix timestamp is

A Unix timestamp counts seconds since January 1, 1970 UTC (the "Unix epoch"). 1744822800 is April 16, 2026, 6:00 PM UTC. Most APIs and databases store time this way because it's unambiguous, timezone-independent, and compact. The Unix timestamp converter goes both directions.

Seconds vs milliseconds

There are two widely-used variants:

  • 10-digit Unix time (seconds) — the classic; what most SQL databases and HTTP headers use
  • 13-digit Unix time (milliseconds) — what JavaScript's Date.now() and most NoSQL databases return

The converter auto-detects which one you pasted — typical timestamps from 2001 to 2286 fall into distinct digit counts, so there's no ambiguity. To handle manually: if it's 10 digits and from any reasonable year, it's seconds; if 13 digits, it's milliseconds.

The year 2038 problem

Classic 32-bit signed Unix timestamps max out at 2147483647 — that's 03:14:07 UTC on January 19, 2038. After that, they overflow to negative and software treats the date as December 1901. Modern systems use 64-bit integers (long long, or BigInt in JS) and are safe until the heat death of the universe. Check your legacy systems.

Timezone handling

Unix timestamps themselves have no timezone — they're a count of seconds that's identical everywhere. But displaying them requires a timezone. The converter shows UTC (the canonical form) plus your local timezone; you can override to any IANA zone (America/New_York, Europe/London, Asia/Tokyo). Daylight saving is handled correctly.

ISO 8601 is the right exchange format

When APIs need to transmit dates in a human-readable way, ISO 8601 (2026-04-16T18:00:00Z) is unambiguous and sortable as a string. Unix timestamps are better for storage; ISO is better for human inspection. The converter shows both.

Batch conversion

Paste a list of timestamps (one per line) to convert many at once — useful for inspecting log files or database dumps. The output table is copyable to spreadsheets.

Related time tools

For computing age from a DOB: age calculator. For span between two dates: date difference calculator. For just epoch conversion (no extra features): epoch converter.

Featured Tools

Try these free tools directly in your browser — no sign-up required.

how to convert unix timestamp unix timestamp converter epoch to date timestamp to human readable convert epoch time

Explore 300+ Free Tools

Utilko has tools for developers, writers, designers, students, and everyday users — all free, all browser-based.