About OpenPacketLoss™

OpenPacketLoss™ is a free, browser-based UDP packet loss and jitter testing tool built by the team behind OpenSpeedTest, a network performance utility that has been running continuously since 2013 and is trusted by millions of users, network engineers, and ISPs across more than 200 countries.

After more than a decade of building and operating OpenSpeedTest, we kept hitting the same blind spot: speed tests tell you how fast your connection is, but nothing about whether it is stable. Packet loss and jitter, the metrics that actually determine whether your video call, game, or VoIP line works, are completely invisible to TCP-based tools. OpenPacketLoss™ was built to close that gap.

Why Existing Tools Miss the Problem

Standard network tests hide packet loss by design.

Speed tests use TCP. TCP automatically retransmits lost data, so a packet drop becomes invisible lag rather than a reported loss event. Your speed test shows 500 Mbps while your Zoom call sounds robotic.

Ping and traceroute use ICMP. Routers routinely deprioritize or rate-limit ICMP probes, so ping loss often has no real relationship to what UDP applications are experiencing on the same connection at the same moment.

How OpenPacketLoss™ Works

The test runs over a WebRTC DataChannel configured with ordered: false and maxRetransmits: 0, forcing true unreliable datagram mode with no buffering, no retransmissions, and no concealment. The client sends packets carrying sequence numbers and high-resolution timestamps. The server analyzes the received sequence to calculate exact packet loss percentage, round-trip latency, and jitter.

This is the same UDP protocol stack used by Zoom, Discord, Microsoft Teams, and Valorant. The result this test returns is what your applications are actually working with.

Who This Is For

Home users and gamers experiencing lag, rubberbanding, or call quality issues that a speed test cannot explain

IT administrators diagnosing packet loss on office networks, specific subnets, or WAN paths

Network engineers and ISPs who need a reproducible, browser-based UDP test without installing anything

Self-hosters and developers who want a private testing node on their own infrastructure

No Installation. No Account. No Data Collected.

Open the page and run the test. OpenPacketLoss™ works natively in all modern desktop and mobile browsers with no plugins, extensions, or sign-up required. We do not log your IP address, store test results, or collect any personally identifiable information. The only output is the raw metric you requested.

Fully Open Source and Self-Hostable

The entire stack, including the server, frontend, and Docker image, is open source and available on GitHub. The server is written in Rust using webrtc-rs, with production-ready multi-architecture Docker images for amd64, arm64, and arm/v7.

Want a private testing node on your LAN, a self-hosted endpoint for your team, or a deployment on your own VPS? Visit the Self-Hosted Server page to get started.

Built on Over a Decade of Network Testing

OpenSpeedTest has been measuring internet performance since 2013. It is deployed by ISPs, embedded in routers, and used by network engineers across more than 200 countries. OpenPacketLoss™ is built on the same infrastructure philosophy: no third-party dependencies, self-hosted first, open source by default.

Questions, bug reports, or deployment help: Contact us or open an issue on GitHub.

Test Your Connection Now

Experience the most accurate WebRTC-based UDP packet loss test directly in your browser. No software to install, no configuration needed. Head back to our homepage and start testing your network stability now.

About OpenPacketLoss™ | The Real UDP/WebRTC Test