How do I know if my game has a cross-platform problem?

Look at how problems distribute across platforms. The defining sign is crashes or bugs on one platform but not another (the game working on the platform you tested but crashing or glitching on another). A sign is problems clustering on a specific platform (crashes, performance issues, or bugs concentrated on one platform, e.g. all on the web build or on mobile). And a sign is complaints you can't reproduce on your platform (players on another platform reporting problems that don't happen on the platform you develop/test on). To diagnose, capture crashes with platform context from the field, so you can see whether problems cluster on a specific platform (the platform breakdown of your crashes/issues). If problems happen on one platform and not another, cluster on a specific platform, or you get complaints you can't reproduce on your platform, you have a cross-platform problem. Platforms (desktop, mobile, web, console) behave differently, run your game in different environments, so a problem specific to one platform's behavior is invisible from the platform that works (where it doesn't occur) but obvious in per-platform data (where the clustering shows). So you know your game has a cross-platform problem from the platform-specific distribution: problems on one platform not another, clustering on a specific platform, complaints you can't reproduce on your platform, all revealed by capturing crashes with platform context (which shows which platform problems concentrate on). The platform context is key, it's what makes a cross-platform problem, invisible from the platform that works, into a findable problem by revealing which platform the problems concentrate on (and thus what platform-specific behavior is causing them). Capturing crashes with platform context from the field is how you see cross-platform problems (especially on platforms you don't primarily test), since the platform breakdown reveals the platform-specific clustering that both confirms a cross-platform problem and points at the cause (the specific platform's behavior).

Why does my game work on one platform but not another?

Because platforms genuinely behave differently, and a game built and tested on one can hit platform-specific problems on another. Each platform, desktop OS, mobile OS, web/WebGL, consoles, has its own runtime behavior, hardware characteristics, APIs, constraints, and quirks, so the same code can run correctly on one and crash, glitch, or misbehave on another due to differences in memory limits, graphics handling, input, file systems, OS behavior, or the platform-specific layers your engine uses. For example, a mobile platform's tight memory can crash a game that's fine on desktop, a web/WebGL build can hit browser-specific issues that don't occur natively, and a console has its own certification requirements and behaviors. These platform-specific problems are invisible from a platform that doesn't have them, so testing only on your primary platform gives no assurance about the others, the problem only manifests on the platform it affects. So your game works on one platform but not another because the platforms differ in ways that matter (memory, graphics, APIs, constraints, platform-specific layers), so a problem specific to one platform's behavior occurs there while the platform you tested (which doesn't have that condition) works. This is why cross-platform games need testing on each platform they ship to (to catch the platform-specific issues), and why capturing crashes per platform from the field is valuable (since you can't fully test every platform, the field data surfaces platform-specific crashes you couldn't reproduce, with the platform context to identify and fix them). The core reason for cross-platform problems is that 'works on platform A' doesn't imply 'works on platform B' when the platforms differ in the ways that matter, so each platform needs its own validation. To find why your game fails on a specific platform, capture crashes with platform context (which reveals the problem clustering on that platform) and investigate that platform's specific behavior (how it differs, memory, graphics, APIs, that's causing the problem). The fix addresses the platform-specific cause (handle the platform's memory limits, graphics differences, API differences). So your game works on one platform but not another because platforms behave differently (so a problem specific to one platform's behavior occurs there but not on the platform you tested), and you diagnose it by capturing crashes with platform context (revealing which platform and pointing at the cause) and addressing the platform-specific behavior causing the problem.

How do I test and fix cross-platform problems?

Test on each platform you ship to, prioritize by usage, capture crashes per platform from the field, and fix the platform-specific causes. Test on each platform you ship to: since platforms behave differently, a problem specific to one platform only surfaces on that platform, so test each platform you actually ship to (at least its critical paths), prioritizing the platforms most of your players are on (so your limited testing covers the most players). This catches the cross-platform problems you can before launch. Since you can't fully test every platform and configuration, capture crashes per platform from the field: this surfaces the platform-specific crashes you couldn't reproduce, with the platform context to identify them (which platform the problem clusters on), effectively extending your coverage across all the platforms you ship to. Then fix the platform-specific causes: use the platform context (which platform the problem is on) to investigate that platform's specific behavior (how it differs, memory, graphics, APIs, that's causing the problem), and fix the cause for that platform (handle the platform's memory limits, graphics differences, API differences, etc.). Verify in the field per platform (the problem stops on that platform on the fixed version). So you test and fix cross-platform problems by testing each platform you ship to (prioritized by usage, to catch what you can before launch), capturing crashes per platform from the field (to surface the platform-specific problems you couldn't reproduce, with the platform context to identify them), and fixing the platform-specific causes (investigating how the affected platform differs and addressing it). The key is that cross-platform problems come from platforms behaving differently, so they're invisible from the platform that works (you can't catch them by testing only your primary platform) and require per-platform testing (for the platforms you can test) plus per-platform field capture (for the platforms and configurations you can't fully test), with the platform context revealing which platform a problem is on (so you can investigate that platform's specific behavior and fix the cause). Capturing crashes with platform context from the field is essential, it's how you see the cross-platform problems on platforms you don't primarily test (the platform clustering reveals them) and diagnose them (the platform points at the cause), so you can fix the platform-specific problems across all the platforms you ship to, even ones you can't fully test yourself. So testing and fixing cross-platform problems combines per-platform testing (for the platforms you can test, prioritized by usage) with per-platform field capture (for the platforms and conditions you can't, surfacing the problems with platform context), and fixing the platform-specific causes (revealed by which platform the problem clusters on), which handles the cross-platform problems that come from platforms behaving differently.

Signs Your Game Has a Cross-Platform Problem

Quick answer: Watch for crashes or bugs on one platform but not another, problems clustering on a specific platform, and complaints you can't reproduce on your platform. Cross-platform problems are invisible from the platform that works but obvious in per-platform data.

Shipping to multiple platforms means each can behave differently, so a cross-platform problem hits one platform while others are fine. Here are the signs your game has a cross-platform problem.

Crashes or Bugs on One Platform but Not Another

The defining sign is crashes or bugs on one platform but not another, the game working on the platform you tested but crashing or glitching on another. If a problem happens on one platform (desktop, mobile, web, console) and not others, it's a cross-platform problem, specific to that platform's behavior.

Bugnet captures crashes with platform context, so platform-specific problems are identifiable. Crashes or bugs on one platform but not another are the defining sign of a cross-platform problem, and capturing crashes with platform context is what reveals it, the platform breakdown shows the problem clustering on one platform, which both confirms it's cross-platform and points at the cause (that platform's specific behavior).

Problems Clustering on a Specific Platform

A sign is problems clustering on a specific platform, crashes, performance issues, or bugs concentrated on one platform (e.g. all your crashes on the web build, or on mobile). If your problems concentrate on one platform while others are fine, you have a cross-platform problem specific to that platform.

Bugnet captures platform context with crashes, so clustering on a specific platform is visible. Problems clustering on a specific platform are a sign of a cross-platform problem, and the platform context reveals the clustering (which platform the problems concentrate on), pointing at the platform-specific cause, since platforms run your game differently, a problem on one platform points at how that platform differs.

Complaints You Can't Reproduce on Your Platform

A sign is complaints you can't reproduce on your platform, players on another platform reporting problems that don't happen on the platform you develop/test on. If players on a platform you don't primarily use report problems you can't reproduce, it's a cross-platform problem on a platform outside your test set.

Bugnet captures crashes with platform context from the field, so problems on platforms you don't test are identifiable. Complaints you can't reproduce on your platform are a sign of a cross-platform problem (on a platform you don't primarily test), and field capture with platform context is how you see and diagnose them, the captured platform and conditions reveal the problem on the platform you can't reproduce it on, so you can fix it.

Watch for crashes or bugs on one platform but not another, problems clustering on a specific platform, and complaints you can't reproduce on your platform. Cross-platform problems are invisible from the platform that works but obvious in per-platform data.