One timestamp per line — auto-detects seconds, milliseconds, and microseconds
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Unix Timestamp Converter — Epoch to Date & Date to Epoch
About this tool
What Is a Unix Timestamp and How Does This Converter Work?
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC — a fixed reference point known as the Unix epoch. It is the universal standard for representing time in software: every major programming language (JavaScript, Python, Java, Go, Rust, PHP), every database (PostgreSQL, MySQL, MongoDB), and virtually every API uses Unix timestamps for storing and transmitting date and time data. A Unix timestamp is a single integer with no timezone ambiguity, making it ideal for calculations, sorting, and comparison. This free online Unix timestamp converter handles every common conversion task in one place: paste any epoch value to see the equivalent human-readable date in multiple formats, pick a date and time to get the Unix timestamp, convert entire batches of timestamps at once, and always see the current epoch time live.
Precision auto-detection is one of the most useful features of this tool. Many developers get tripped up by the difference between seconds (10-digit timestamp like 1700000000), milliseconds (13-digit like 1700000000000), and microseconds (16-digit). JavaScript's Date.now() returns milliseconds. Most Unix/Linux system tools return seconds. Some databases and tracing systems use microseconds. Paste any of these and the tool automatically identifies the precision and converts correctly — no manual switching between modes.
The timezone-aware display shows your local timezone, UTC, and any third timezone you search for simultaneously in the Epoch → Date panel. This is essential when debugging API responses, interpreting log files from servers in different regions, or working with users across time zones. The Quick Reference chips let you instantly load common reference points — Today midnight, Yesterday, 1 week ago, the Unix epoch itself, and Y2K — with one click. The Batch Converter handles multiple timestamps at once: paste a column of epoch values from a CSV export or log file and get a table of human-readable dates instantly.
Features
- Live current Unix time — shows seconds, milliseconds, and ISO 8601, updating every second
- Epoch → Date: paste any timestamp and get ISO 8601, UTC, RFC 2822, local time, day of week, and relative time
- Date → Epoch: date + time picker outputs Unix seconds, milliseconds, and ISO 8601 simultaneously
- Auto-detects precision — seconds (10-digit), milliseconds (13-digit), microseconds (16-digit)
- Searchable timezone picker — shows local timezone, UTC, and any selected timezone side by side
- Batch converter — paste one timestamp per line, get a conversion table with ISO 8601 and relative time
- Quick Reference chips — Today midnight, Yesterday, 1 week ago, 30 days ago, Unix epoch, Y2K
- 100% client-side — uses browser Date and Intl APIs, no server upload, works offline
How to Use
The Live Current Time card at the top always shows the current Unix timestamp in seconds, milliseconds, and ISO 8601 format, updating every second. Click Copy next to any format to copy it to your clipboard instantly.
To convert an epoch timestamp to a human-readable date, paste it into the Epoch → Date panel. The tool auto-detects whether your timestamp is in seconds, milliseconds, or microseconds and labels the precision in the header. The results panel shows every useful format simultaneously: ISO 8601, UTC String, RFC 2822, your local timezone, UTC, any timezone you've selected in the header picker, day of week, and a relative description like "3 hours ago" or "in 2 days". Click Now to load the current timestamp.
To convert a date to a Unix timestamp, use the Date → Epoch panel. Pick a date using the date input and set a time using the time input (defaults to your current local date and time). The panel outputs Unix seconds, Unix milliseconds, ISO 8601 UTC, and relative time. Click Now to reset to the current moment.
Use the Timezone picker in the header to add a third timezone to the Epoch → Date output. Type any city name or timezone name — "Tokyo", "America/New_York", "Europe/Berlin" — and the matching timezone appears in the dropdown.
The Quick Reference chips at the bottom let you load common timestamps instantly — click "Today midnight" to load midnight of today, "Unix epoch" to load 0, or "Y2K" to load January 1, 2000. The selected timestamp populates the Epoch → Date panel automatically.
For bulk conversion, paste multiple timestamps (one per line) into the Batch Converter textarea. The table shows each input alongside its Unix seconds, ISO 8601 date, and relative time. Mixed precisions in the same batch are handled correctly.
Common Use Cases
Frequently Asked Questions
A Unix timestamp is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC (the Unix epoch). It is a single timezone-independent integer used universally in programming, databases, and APIs to represent any moment in time. All major languages support it natively.
A seconds timestamp is 10 digits (e.g. 1700000000). A milliseconds timestamp is 13 digits (e.g. 1700000000000). JavaScript's Date.now() returns milliseconds. Linux date +%s returns seconds. This tool auto-detects which you've pasted and converts correctly — look for the precision badge next to the panel title.
The current Unix timestamp is shown live at the top of this page and updates every second. You can also run Math.floor(Date.now()/1000) in any browser console to get it in seconds, or Date.now() for milliseconds.
Use new Date(timestamp * 1000).toISOString() for a seconds timestamp, or new Date(timestamp).toISOString() for milliseconds. For local time: new Date(ts * 1000).toLocaleString(). For UTC: new Date(ts * 1000).toUTCString(). This tool shows all formats at once so you can copy the one you need.
ISO 8601 is a standardised human-readable date format: 2024-01-15T10:30:00.000Z. The T separates date from time, and the Z suffix means UTC. It is the recommended format for APIs, JSON payloads, and file metadata because it is unambiguous and sortable alphabetically.
The Unix epoch was chosen as a practical reference when Unix was developed in the early 1970s. It predates all real-world computer usage at the time, making all timestamps positive integers. The exact date was arbitrary — it just needed to be a fixed point in the past. Every major language and system uses the same epoch.
The Y2K38 problem affects 32-bit systems that store Unix timestamps as a signed 32-bit integer. The max value overflows on January 19, 2038 at 03:14:07 UTC, causing timestamps to roll back to negative numbers. Modern 64-bit systems are completely unaffected and can represent dates billions of years in the future.
Yes — use the Batch Converter at the bottom of the page. Paste one timestamp per line (mixing seconds, milliseconds, and microseconds is fine — each line is auto-detected separately). The output table shows Unix seconds, ISO 8601, and relative time for every line.
No. All conversions run entirely in your browser using JavaScript's built-in Date and Intl APIs. No data is sent anywhere. The tool works offline once the page has loaded.
RFC 2822 is the date format used in email headers: Mon, 15 Jan 2024 10:30:00 +0000. It is also used in HTTP headers and RSS/Atom feeds. This tool outputs RFC 2822 alongside ISO 8601 and UTC string formats for every timestamp conversion.