How to Fix a Pygame Platformer Where Jump Height Changes With Frame Rate

A Pygame jump that reaches different heights at 30 and 120 fps is frame-rate dependent integration. Scale physics by dt. Here is how.

How to fix it

1. Get dt from the clock

Use dt = clock.tick(fps) / 1000.0 to get the seconds elapsed since the last frame, and pass it into your update logic.

2. Scale gravity and position by dt

Apply vel_y += gravity * dt and y += vel_y * dt. Now the same real time produces the same arc whether the loop runs fast or slow.

3. Consider a fixed timestep for stability

For very high or unstable frame rates, accumulate time and run physics in fixed steps. This keeps integration exact and avoids tunneling at low frame rates as well.

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 Pygame 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.