Quick Start

Quick start

From nothing to a measured link. Everything here runs on one host and stays on your network.

What you need

• A Linux host on the LAN with Docker and the compose plugin.
• Nothing else. There is no account, no API key, and no external service to register with.

The container image is public, so no docker login is needed to pull it.

Run it

git clone https://github.com/sremich/lan-speedtest.git
cd lan-speedtest
cp .env.example .env          # fill in; never commit it
docker compose up -d

Comment out the three SPEEDTEST_TLS_* lines in .env for a first run. They point at a certificate you do not have yet, and the service refuses to start rather than falling back to plain HTTP — deliberately, because a silent downgrade to unencrypted is a worse outcome than a refusal. Plain HTTP on 8080 is the right way to try it; Deployment covers adding TLS.

Then open the host in a browser — http://HOST:8080/ unless you have set up TLS. The test starts as soon as the page loads, so the first thing you see is a run already in progress:

One chevron per request the profile will issue, coloured by stage: blue for latency, orange for download, purple for upload, red for packet loss. The line above names the stage running right now.

When it finishes you have the full picture — see Reading the Results for what each figure means.

The one setting to get right

SPEEDTEST_PROFILE picks how much data to move and how to interpret it. The shipped profiles are lan-1g, lan-2.5g, lan-10g and quick:

# in .env
SPEEDTEST_PROFILE=lan-1g

Getting this wrong does not produce an error — it produces a plausible wrong answer. A profile sized for a slower link finishes its transfers too fast to count as loading the connection, and the quality ratings then disappear with nothing said. Configuration explains the sizing rules.

If you would rather not choose, the picker in the page offers Auto, which measures the link with one short transfer and then selects a profile to match.

Then, in rough order of value

Next	Why
Deployment	TLS, the firewall, and pinning an image tag — what a permanent install needs
TURN and Packet Loss	Without a relay there is no packet-loss figure, and the quality ratings shift
Configuration	Naming the deployment, retention, reverse DNS, metrics
Reading the Results	Especially the loaded-minus-idle latency difference

Light and dark

The page follows the browser's own light/dark preference and has a toggle beside the profile picker. The choice is remembered per browser.

A stored run in the light theme. Every page carries the same toggle.

Turning off auto-start

A run moves hundreds of megabytes, which is the last thing you want during the video call that made you suspicious of the network in the first place. It can be turned off three ways, most specific first — see Configuration.

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See also: Deployment · Configuration · Reading the Results · Troubleshooting