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List of Top Public Time Servers

Google Public NTP [AS15169]:

Cloudflare NTP [AS13335]:

Facebook NTP [AS32934]:

Microsoft NTP server [AS8075]:

Apple NTP server [AS714, AS6185]:


NIST Internet Time Service (ITS) [AS49, AS104]:


Stratum 1:

Stratum 2:


Stratum 1:


Stratum 1:

Stratum 2: Москва


Stratum 1:

Stratum 1:

Stratum 2:

Company Delfa Co. Ltd. [AS8915]: [AS1853]:

Berkeley [AS25]:

Stratum 1:

Georgia State University [AS10631]:

University of Saskatchewan [AS22950]:

NSU [AS3335]:

Stratum 2:

ITAEC [AS41783]:

RSU [AS47124]:

Stratum 1:

National Institute of Information and Communications Technology [AS9355]:

NTT [AS2914]: [AS6939]:

TRC Fiord [AS28917]:

Netnod NTP service [AS57021]:

Stratum 1:





Anycast address for nearest NTP server of the above:

QiX NTP [AS14086]:

YYCIX NTP [AS396515]:

MSK-IX NTP [AS43832]:

Stratum 1:

Hetzner Online [AS24940]:

Trabia-Network [AS43289]:

RIPE [AS3333]:

Internet Systems Consortium [AS1280]: (prev

TimeNL/SIDN Labs [AS1140]: (

Kantonsschule Zug [AS34288]:


Chinese Academy of Sciences Nation Time Service Center [AS4808, AS9808, AS23724]:

Nat Morris [AS30746]:

Stratum 1:

NTP Pool:



























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OpenWRT also operates NTP servers:

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Ubiquiti time servers

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rail01 commented Jul 10, 2022

I made a separate gist with Polish NTP servers only and their details, I'm more than fine with my list being copied here:

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mdavids commented Oct 11, 2022

TimeNL ( is a pool nowadays, consisting of and (see
Also, there are two NTS-capable systems available; and

Copy link is a valid public time source as well.

Copy link -- HE has three public NTP servers

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ravench commented Jan 2, 2023

The Swiss Federal Institute of Metrology
Laboratory Photonics, Time and Frequency runs it's own time / atomic clock and offers three public NTP servers.

METAS operates three public stratum 1 NTP servers in open access policy, namely:

The alias points to one of the above servers.

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mqudsi commented Jan 10, 2023

The recently-added-to-the-list is a stratum 3 server/pool and probably useless for most.

mqudsi@freebsd> ntpdate -q
server 2606:4700:f1::123, stratum 3, offset -0.000278, delay 0.03026
server 2606:4700:f1::1, stratum 3, offset -0.000490, delay 0.02956
server, stratum 3, offset -0.000189, delay 0.03023
server, stratum 3, offset -0.000497, delay 0.02959

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cygvis commented Jan 10, 2023

Could somebody ELI5 what "stratum" is for me and anybody else that doesn't know?

Is it something I can use on a home network? If not, what's the best public server in the US/NA?

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cadusilva commented Jan 10, 2023

Could somebody explain what "stratum" is for me and anybody else that doesn't know?

The stratum indicates how close to the "absolute time" the NTP server is. Zero is the source of time, like a GPS device or atomic clock. Stratum 1 is the server that connects to the absolute clock source (stratum 0) and provides its time info to other clients and servers. Stratum 2 is a server that gets its time info from the stratum 1 server. Stratum 3 gets its time from a stratum 2 server and so on until stratum 16 when clients and servers don't trust the time provided. There are others stratum levels but you get the idea.

@cygvis here I use a GPS USB dongle as time source for my local network and also to the NTP Pool. The middleman is a Chrony server that gets the time from the GPS and provides a stratum 1 public time server.

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cygvis commented Jan 11, 2023

@cadusilva Oh okay, that makes more sense. Do you or does anybody know what stratum Google and Apple time servers are?

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@cygvis you can check the stratum of any NTP time server using this service.

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cygvis commented Jan 11, 2023

@cadusilva nice tool thanks. Looks like they're both Stratum 1

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@cygvis just be aware that Google (and Facebook) uses leap smearing. Using them both together or with other servers that don't use leap smearing can cause unexpected clock corrections or failure to sync, according to Red Hat.

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mqudsi commented Jan 11, 2023

Apple’s pool is a mix of stratum 1 and stratum 2. Depends on which server you end up with.

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rail01 commented Feb 12, 2023

EPIX, Polish non-commercial Internet Exchange and IP transit operator hosts

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n1zyy commented Mar 1, 2023

Note that all the *, *, *, etc. names are just vendor zones and don't actually point to distinct pools of servers. My understanding is that this is done to allow some rough mapping of traffic (via DNS) from each vendor, and maybe to allow them to turn off a vendor zone if they pull a Netgear or D-Link and ship what turns out to be a terribly buggy NTP implementation that egregiously abuses servers.

It doesn't really make sense to try configuring other vendor's names because they all just point to the same global pool of servers.

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pnahco commented May 8, 2023

.ir (Iran)

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Ubuntu uses

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Lofty73 commented Jun 6, 2023

Hi thanks. It seems to be an ongoing issue with me. Everything works perfect except the time server issue.
Will give it a try when I have rebuilt my dead PC

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In Spain, we have several Stratum 1:

  • (pool composed by and
  • (NTS Authentication)
  • server

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I am trying to connect to some stratum 1 international time servers (currently located in the US), but it seems I am not reaching any of them. I was able to connect to ones in the US. Does anyone know why this may be happening?

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hvia commented Jul 26, 2023

NTP / NTS server free to use worldwide (better performance for western Europe), located in France, stratum-2 :

see its info page @

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ziptx commented Aug 14, 2023

Great list. Would be really helpful to know which entries hold to the leap smearing standard. Regular NTP and smeared servers should not be mixed together. [no smearing] [smearing] [smearing]

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gdriggs commented Aug 14, 2023 via email

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PRSXFENG commented Mar 3, 2024

National Institute of Information and Communications Technology, Japan has a NTP server at


PS, my Brother printer connects to for NTP which appears to just CNAME to the above mentioned NTP Server

the FAQ section of NICT's NTP server also directs you to Internet Multifeed Co. which also runs a few NTP servers

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CroZg commented Mar 16, 2024

Croatia .hr:

Stratum 1 dynamic IP

Stratum 2 Osijek Rijeka Split Zagreb Zagreb

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francisuk1989 commented Jun 14, 2024

United Kingdom Stratum 1
Some NTP below maybe restricted to UK / Ireland IPs so if you in BST/GMT timezone you should be fine. is located near Leeds, UK UK UK UK UK  is located near Bournemouth, UK  is located near Mansfield, UK - Cornwall, UK - is located in Claremont, Western Australia

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