Test Mode Selection

Basic Mode

Test your browser time against our NTP reference. No setup required.

Bridge Mode

Test any NTP server via local bridge. Supports RFC1918 IPs.

CLI Script

Download shell script for server-side testing.

Basic Time Test

Test your system's time synchronization against our Stratum 1 NTP reference server.

NTP Bridge Testing

Bridge Not Connected

Start the local bridge server to test NTP servers directly.

Quick Start:

# 1. Download and install
cd /tmp && curl -sL https://online-ntp-validator.com/bridge/ntp-bridge.tar.gz | tar xz
cd ntp-bridge && npm install

# 2. Start the bridge
node server.js
# Bridge running on ws://localhost:8080

# 1. Prerequisites: Node.js (via Homebrew if needed)
brew install node

# 2. Download and install
cd /tmp && curl -sL https://online-ntp-validator.com/bridge/ntp-bridge.tar.gz | tar xz
cd ntp-bridge && npm install

# 3. Start the bridge
node server.js
# Bridge running on ws://localhost:8080

# PowerShell - 1. Prerequisites: Node.js
# Download from https://nodejs.org/

# 2. Download the bridge
Invoke-WebRequest -Uri "https://online-ntp-validator.com/bridge/ntp-bridge.zip" -OutFile "$env:TEMP\ntp-bridge.zip"
Expand-Archive -Path "$env:TEMP\ntp-bridge.zip" -DestinationPath "$env:TEMP\ntp-bridge" -Force
cd "$env:TEMP\ntp-bridge"

# 3. Install and start
npm install
node server.js
# Bridge running on ws://localhost:8080

Or download manually: server.js | package.json

Bridge URL:

CLI Testing Script

Download our bash script for server-side NTP testing.

# One-liner test
curl -sL https://ntp.rdem-systems.com/ntp-check.sh | bash

# Or download and run
wget https://ntp.rdem-systems.com/ntp-check.sh
chmod +x ntp-check.sh
./ntp-check.sh

Download ntp-check.sh

NTP Compliance Validation Checklist

Download our 15-point checklist to ensure your NTP infrastructure meets audit requirements:

Infrastructure

Multiple NTP sources configured (≥4)
Stratum 1 or 2 servers used
Geographic diversity of sources
Internal NTP hierarchy defined
Failover mechanisms in place

Security

UDP 123 firewall rules documented
NTP amplification protection
Access control lists configured
Monitoring and alerting active
Logs retained per policy

Validation

Offset within acceptable range
No false tickers detected
Reach value at 377
Regular sync verification
Documentation up to date

RDEM Systems provides enterprise-grade NTP services trusted by organizations across Europe.
Verify our NTP Pool contribution and reliability score (AS206014) →

Online NTP Validator