Slightly different output of Three.js canvas screenshot in headed vs headless mode

[mikatalk]

As the title mentions, there seems to be a very small difference in brightness when taking a screenshot of a webgl rendered canvas, in headed vs headless mode.

I created a project on Github to replicate the issue using one of the three.js examples.

# install
npm install
# run server
npm run server
# headed run
npm run cypress:run
# headed open
npm run cypress:open

The two files output:

• headed
• headless

It's easier to overlap them back and forth to see the small difference.

Is it a know issue or did I miss a setting? Is it even possible to get a perfectly matching output?

Thank you!

[mikatalk]

Solved it by using the Chrome flag --use-gl=angle