xvfbwrapper

Manage headless displays with Xvfb (X virtual framebuffer)

About

xvfbwrapper is a Python library for managing X11 virtual displays with Xvfb (X virtual framebuffer), a virtual X server that runs without a physical display. It provides the Xvfb class, a Python interface for configuring and controlling the Xvfb program.

See the module API documentation for more information.

• Copyright (c) 2012-2026 Corey Goldberg
• Development: GitHub
• Releases: PyPI
• License: MIT

Status

Latest Version
Build/Tests (CI)
Supported Python Versions
OSS Sponsorship

What is Xvfb?

Xvfb (X virtual framebuffer) is a display server implementing the X11 display server protocol. It runs in memory and does not require a physical display or input device. Only a network layer is necessary.

Xvfb allows GUI applications that use X Windows to run on a headless system.

Installation

Official releases are published on PyPI:

pip install xvfbwrapper

System Requirements

• Python 3.10+
• X Window System
• Xvfb (sudo apt-get install xvfb, yum install xorg-x11-server-Xvfb, etc)
• Support for file locking using fcntl (POSIX systems)

Examples

Basic Usage:

Note: Always either wrap your usage of Xvfb() with try/finally, or use it as a context manager to ensure the display is stopped. If you don't, you'll end up with a bunch of junk in /tmp if errors occur.

from xvfbwrapper import Xvfb

xvfb = Xvfb()
xvfb.start()
try:
    # launch stuff inside virtual display here
finally:
    xvfb.stop()

Usage as a context manager:

from xvfbwrapper import Xvfb

with Xvfb():
    # launch stuff inside virtual display here
    # (Xvfb will stop when this block completes)

Specifying display geometry:

from xvfbwrapper import Xvfb

xvfb = Xvfb(width=1280, height=720)
xvfb.start()

Specifying display number:

from xvfbwrapper import Xvfb

xvfb = Xvfb(display=23)
xvfb.start()  # Xvfb will start on display :23

Setting XDG_SESSION_TYPE:

When running Xvfb in a Wayland session, GUI toolkits may try to use the Wayland backend instead of connecting to Xvfb. Setting set_xdg_session_type=True forces XDG_SESSION_TYPE=x11 in the Python process and all child processes, ensuring that GUI apps use the X11 backend and can render on the virtual display.

from xvfbwrapper import Xvfb

xvfb = Xvfb(set_xdg_session_type=True)
xvfb.start()

Specifying other Xvfb options:

The Xvfb executable accepts several types of command line arguments.

The most common is an argument with a - prefix and a parameter (i.e. -nolisten tcp). These can be added as keyword arguments when creating an xvfbwrapper.Xvfb instance. For example:

from xvfbwrapper import Xvfb

xvfb = Xvfb(nolisten="tcp")
xvfb.start()  # Xvfb will be called with the `-nolisten tcp` argument

However, there are other possible types of arguments:

• unary argument (i.e. ttyxx)
• unary argument with a + prefix (i.e. +xinerama)
• unary argument with a - prefix (i.e. -nocursor)
• argument with a parameter (i.e. c 100)
• argument with a + prefix and a parameter (i.e. +extension RANDR)

Any type of argument can be added as an extra_args sequence when creating an xvfbwrapper.Xvfb instance. For example:

from xvfbwrapper import Xvfb

xvfb = Xvfb(extra_args=("ttyxx", "-nocursor", "+extension", "RANDR"))
xvfb.start()  # Xvfb will be called with the `ttyxx -nocursor +extension RANDR` arguments

Multithreaded execution:

To run several Xvfb displays at the same time, you can use the environ keyword when starting the Xvfb instances. This provides isolation between processes or threads. Be sure to use the environment dictionary you initialize Xvfb with in your subsequent calls. Also, if you wish to inherit your current environment, you must use the copy method of os.environ and not simply assign a new variable to os.environ:

import os

from xvfbwrapper import Xvfb

isolated_environment1 = os.environ.copy()
xvfb1 = Xvfb(environ=isolated_environment1)
xvfb1.start()

isolated_environment2 = os.environ.copy()
xvfb2 = Xvfb(environ=isolated_environment2)
xvfb2.start()

try:
    # launch stuff inside virtual displays here
finally:
    xvfb1.stop()
    xvfb2.stop()

Headless browser tests:

This uses selenium and xvfbwrapper to run a test on Chrome inside a headless display.

import os
import unittest

from selenium import webdriver
from xvfbwrapper import Xvfb


class TestPage(unittest.TestCase):
    def setUp(self):
        xvfb = Xvfb(set_xdg_session_type=True)
        xvfb.start()
        self.driver = webdriver.Chrome()
        self.addCleanup(xvfb.stop)
        self.addCleanup(self.driver.quit)

    def test_selenium_homepage(self):
        self.driver.get("https://www.selenium.dev")
        self.assertIn("Selenium", self.driver.title)


if __name__ == "__main__":
    unittest.main()

• virtual display is launched
• browser launches inside virtual display (headless)
• browser quits during cleanup
• virtual display stops during cleanup

Development

• Git: github.com/cgoldberg/xvfbwrapper.git

• Create a virtual env and install required testing packages:

  python -m venv venv
  source ./venv/bin/activate
  pip install --editable --group dev --group test .
  

• Run all tests in the default Python environment:

  pytest
  

• Run all tests, linting, and type checking across all supported/installed Python environments:

  tox