Free time API

Exact UTC as JSON, from our reference clock in Frankfurt, which is synchronised with Germany’s national time institute PTB. Free, no key, no sign-up, and usable directly from web pages.

Current time

GET https://time.exact-time.eu/api/v1/time

Example response:

{
  "unixtime": 1793091821,
  "unixtime_ms": 1793091821487,
  "utc": "2026-10-27T09:03:41.487Z",
  "tai_minus_utc_s": 37,
  "gps_minus_utc_s": 18,
  "leap_second_pending": false,
  "reference": {
    "synced": true,
    "source": "PTB, Braunschweig (DE)",
    "host": "ptbtime1.ptb.de",
    "stratum": 2,
    "uncertainty_ms": 3.5,
    "status_age_s": 28
  },
  "note": "Timestamp taken when the request was processed. …",
  "docs": "https://exact-time.eu/time-api"
}

Fields

Field	Meaning
`unixtime`, `unixtime_ms`	Seconds and milliseconds since 1970-01-01 00:00:00 UTC, when our server processed the request
`utc`	The same moment in ISO 8601, with milliseconds
`tai_minus_utc_s`, `gps_minus_utc_s`	Current offsets of atomic time and GPS time from UTC (see time scales)
`leap_second_pending`	`true` if our atomic time sources announce an upcoming leap second
`reference.synced`	`false` if our server has lost its atomic reference; treat the time with caution then
`reference.uncertainty_ms`	Upper bound of our server’s difference from atomic time, from chrony

NTP server test

GET https://time.exact-time.eu/api/v1/ntp-test?host=ptbtime1.ptb.de

Queries a public NTP server four times from Frankfurt and checks NTS support. This is the API behind our NTP server tester; it takes about five seconds.

Examples

# Shell
curl -s https://time.exact-time.eu/api/v1/time

// JavaScript (browser or Node.js 18+)
const t = await (await fetch('https://time.exact-time.eu/api/v1/time')).json();
console.log(t.utc);

# Python
import json, urllib.request
t = json.load(urllib.request.urlopen('https://time.exact-time.eu/api/v1/time'))
print(t['utc'])

For the best accuracy, measure the round trip of your request and add half of it to unixtime_ms. That is what our own pages do, several times, keeping the fastest result.

Limits and fair use

Time: up to 60 requests per minute per address, with short bursts of up to 20. Over the limit you get HTTP 429.
NTP test: up to 10 tests per 10 minutes per address, and each target server at most a few times per minute.
CORS is enabled for all origins, so the API works directly from web pages.
No guarantee. This is a free service run on a small server. Do not build anything critical on it.
To keep a computer’s clock right, use NTP, not this API. NTP is more accurate and designed for it; see our NTP server list.
A link to exact-time.eu where you use the API is appreciated.