Free & open-source SNTP app

Time sync made simple.

Install the app. Enter your NTP/SNTP server IP address. Done. AR Fast SNTP synchronizes your computer clock and shows you what’s happening — without editing NTP configuration files.

Download for Windows Linux x64 beta

Latest Windows release · Free & open source · View source on GitHub

Actual AR Fast SNTP Windows Studio with two NTP servers: one selected, stratum, offset, RTT and expanded Status History. — AR Fast SNTP Studio · actual Windows app

Get started

Three steps. No complicated configuration.

Install AR Fast SNTP

Download and install the Windows desktop app.

Enter your server IP

Use your GPS/NTP server address or another trusted SNTP server.

Watch it sync

Check the selected server, clock status, and response time.

New to NTP? Follow the beginner's quick start.

The real Windows application

See your time synchronization at a glance.

These are real screenshots from the Windows app. Click any image to view the full size.

Studio with one active selected time server and one nonresponding server — **Know which server is selected**See each server’s connection status.

Add NTP Server dialog showing IPv4 address input and Add Server button — **Enter your server IP**Add a time source right in the app.

Remove NTP Server confirmation dialog while other NTP sources remain active — **Manage your server list**Add or remove sources whenever you need.

Made for everyday engineering work

More than one time server

Manage up to 16 IPv4 time servers and choose which ones to use.

Syncs in the background

Keep synchronization running after you close the app window. Server settings stay saved.

Status you can understand

See the selected server, clock offset, response time, and recent events.

In tests on four Windows industrial HMI computers, time correction was observed in around one second, with recovery after reconnecting LAN in approximately six seconds. Actual timing depends on the network and server.

Choose your platform. Windows download & setup · Linux x64 beta · Help and troubleshooting. Use a PC where you are permitted to change system time.