Quickstart

This guide takes you from nothing to a first result.

Prerequisites

• Python 3.13 or later
• Node.js 24 or later
• Google Chrome or Firefox

Step 1: Get Webperf Core

git clone https://github.com/Webperf-se/webperf_core.git
cd webperf_core

Step 2: Install dependencies

python -m pip install --upgrade pip
pip install -r requirements.txt
npm install --omit=dev

Step 3: Check the installation

python default.py --dependency

This validates your installation and tells you what's missing. If you only want the help text, python default.py -h is enough.

Step 4: Run your first test

python default.py -u https://webperf.se -t 22 -r

• -u is the address to test
• -t 22 picks the energy efficiency test, which measures how much data the page sends
• -r prints the review, that is, the list of what should be fixed

Without -r you only get the score, which is rarely what you want when troubleshooting.

Understanding the result

Every test produces a score between 1.0 and 5.0.

Next steps

Run several tests

Give several test numbers separated by commas:

python default.py -u https://example.com -t 22,9 -r

Run everything except one test

A negative number excludes a test. With no -t at all, everything runs.

# every test except email (24)
python default.py -u https://example.com -t -24

Test several websites

Create a sites.json:

[
  [1, "https://example1.com"],
  [2, "https://example2.com"]
]

Run it with:

python default.py -i sites.json -t 22

Save the result

python default.py -u https://example.com -t 22 -o result.json

The file extension decides the format: .json, .csv, .sql, .sqlite or .md.

Change the report language

python default.py -u https://example.com -t 22 -r -L en

Common problems

python3 default.py -h

node --version

sudo apt install google-chrome-stable
# or
sudo apt install firefox

Further reading

• Full local install: more detail and troubleshooting
• All tests: what each test does
• Command line arguments: every flag