# Unix Timestamp Converter

> Convert Unix timestamps to readable dates and back, with a live current-time readout.

URL: https://uttir.com/unix-timestamp-converter
Categories: developer-tools
Privacy: All conversion happens locally in your browser.

## About

Unix time counts seconds since 00:00:00 UTC on 1 January 1970. It is compact and timezone-free, which is why logs, databases, and APIs use it — but humans cannot read 1700000000 at a glance. This converter translates both directions instantly.

It auto-detects whether a value is in seconds or milliseconds, shows the date in ISO 8601, UTC, and your local timezone, and includes a live readout of the current Unix time.

## How to use

1. **Paste a timestamp** — Seconds (10 digits) or milliseconds (13 digits) — the unit is detected automatically.
2. **Read the date** — ISO, UTC, local, and relative representations appear instantly.
3. **Or pick a date** — Use the date picker to get the matching Unix seconds and milliseconds.

## Examples

### Seconds to date

A 10-digit value is treated as seconds.

Input:

```
1700000000
```

Output:

```
2023-11-14T22:13:20.000Z
```

## FAQ

### Seconds or milliseconds — which do I need?

JavaScript’s Date.now() returns milliseconds; most Unix systems and JWT exp claims use seconds. The tool detects which you pasted and labels it.

### Why does the local time differ from UTC?

A timestamp is a single instant; timezones are just different ways of displaying it. The UTC and local lines show the same moment in two zones.

### Seconds or milliseconds?

JavaScript uses milliseconds; most server-side languages use seconds. The tool has a toggle so you can switch. A 1000x difference between the same moment in two systems is a common bug.

## Related tools

- [JWT Decoder](https://uttir.com/jwt-decoder) — Decode a JWT’s header and payload and check its expiration — without sending it anywhere.
- [Time Zone Converter](https://uttir.com/time-zone-converter) — Convert times between time zones and compare them side by side.
- [UUID Generator](https://uttir.com/uuid-generator) — Generate cryptographically random UUID v4 identifiers, one or a thousand at a time.

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For the full HTML page with the live tool, visit https://uttir.com/unix-timestamp-converter.
This file is the markdown rendering at https://uttir.com/unix-timestamp-converter.md. See https://uttir.com/llms.txt for a site-wide summary.