pytest-playwright-visual-snapshot 0.1.0

Easy pytest visual regression testing using playwright

Pytest Plugin for Visual Testing with Playwright

As of 2025-03-22 of all of the existing packages to do simple visual regression testing using playwright are long dead. I had a bunch of updates I wanted to make to existing systems so I rewrote the plugin with a bunch of updates:

• snapshots are always written on CI
• ability to mask out certain elements
• failing on --update-snapshots to make users manually review images
• snapshot name is optional, test_name[browser][os].png is auto-generated by default
• multiple snapshots in a single test, file names are auto incremented
• updated folder structure: snapshots/file_name/test_name/test_name[browser][os].png
• ability to configure directories, etc via ini + pytest config.

You can see this implemented in a working project here.

Installation

pip install pytest-playwright-visual-snapshot

Usage

This plugin provides a assert_snapshot fixture which is used to create snapshots and compare it.

def test_myapp(page, assert_snapshot):
    page.goto("https://example.com")
    assert_snapshot(page)

Then, run pytest:

pytest

The first time you run pytest, snapshots will be created, and you will get the error:

New snapshot(s) created. Please review images

The next run, the snapshots comparison will take place. To update snapshots, run:

pytest --update-snapshots

After updating, tests will fail and you will need to review images.

In case of a mismatch, snapshot_tests_failures folder will be created with actual_.., expected_.. and diff_.. images generated.

Configuration

View all configuration options by running pytest --help. Here's a quick example:

# NOTE this runs on any pytest invocation, even if no tests are run
def pytest_configure(config: Config):
  config.option.playwright_visual_snapshots_path = Path("...")
  config.option.playwright_visual_snapshot_failures_path = Path("...")

API

• threshold - sets the threshold for the comparison of the screenshots:0 to 1. Default is 0.1

• fail_fast - If True, will fail after first different pixel. False by default

Alternatives

• https://github.com/kumaraditya303/pytest-playwright-snapshot - long dead
• https://github.com/symon-storozhenko/pytest-playwright-visual - fork of the above repo, long dead
• https://github.com/Visual-Regression-Tracker/Visual-Regression-Tracker - requires a separate server to run