How to Fix a Non-Power-of-Two WebGL Texture Rendering Black

WebGL 1 has strict completeness rules for non-power-of-two textures. The default sampler state expects mipmaps and repeat wrapping, which NPOT textures cannot satisfy, so they render black. Here is how to fix it.

How to fix it

1. Set clamp wrapping

After uploading an NPOT texture call gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE) and the same for TEXTURE_WRAP_T.

2. Use a non-mipmap filter

Set gl.TEXTURE_MIN_FILTER to gl.LINEAR or gl.NEAREST and skip generateMipmap, since NPOT textures cannot be mipmapped in WebGL 1.

3. Or upgrade to WebGL 2

WebGL 2 removes the NPOT restrictions, so requesting a webgl2 context lets you use repeat wrapping and mipmaps on NPOT textures normally.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every HTML5 error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.