glslop GPU check

Thanks for running this. It takes about a minute and tells us whether glslop's experimental second renderer works correctly on your graphics hardware.

Nothing is sent anywhere. The page has no server. When it finishes it shows you a block of text — read it if you like, then copy it and send it back however you got this link.

It draws a handful of tiny test images off-screen. It does not run any of the heavy shaders from the site, so it will not tie up your graphics driver.

Also measure shader compile times (optional, slower)

This one is the question we most need answered, and it is the only part that is any trouble to run. It compiles twelve real shaders from the site, from the cheapest in the corpus up to the worst, and times both renderers on each.

Why it matters. The reason a second renderer exists at all is that on Windows the Direct3D shader compiler takes up to 190 seconds on our heaviest shader, while the newer path does the same work in about two. Nobody knows whether that happens on any machine other than the one it was found on — that is what your run would tell us.

What it costs you. Around a minute by default. It stops as soon as one shader takes longer than 30 seconds, and it never starts another compile after that. Checking the box below removes that stop, which can take up to 15 minutes and is only worth doing if you do not need the machine meanwhile.

The honest warning. Compiling very heavy shaders can make the graphics driver unresponsive for a while, and on rare occasions the browser resets its GPU process — that closes anything else on screen that is using WebGL, like a game or a map. Nothing is damaged and a reload fixes it, but do this when you are not in the middle of something.

The first run is the one that counts, because shader compilers cache their work and a repeat run can report the cache instead of a real compile. You do not have to keep track of that: at the end the page recompiles one shader with a tiny change that no cache can have seen before, and the result says whether the numbers above it are real. A second run is not wasted — the check is what tells us either way.

Only if we ask you to: the button below measures the WebGPU half on its own. It never compiles a heavy shader the old way, so it takes about a minute, it cannot make the driver unresponsive, and it reaches the shaders the normal run gives up on. It is also safe to run more than once: every shader is altered very slightly before it is built, so your machine cannot hand back something it prepared earlier and have that look like a fast result.