How to Fix a Blurry Web Game From Ignoring Device Pixel Ratio

On a Retina laptop the game looks fuzzy while native apps are crisp. The canvas rendered at logical resolution and got upscaled. Render at the device pixel ratio instead.

How to fix it

1. Scale the backing store

Set canvas.width = cssWidth * devicePixelRatio (and height likewise) so the drawing buffer has real device pixels, while leaving the CSS width/height in logical units.

2. Match the context transform

For 2D contexts, call ctx.scale(dpr, dpr) so your drawing coordinates stay logical; for WebGL set the viewport to the scaled size.

3. React to DPI changes

Listen for resize and DPI-change media queries and re-size the canvas, since moving a window between monitors can change the pixel ratio.

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.