What's the difference between a crash and a hang?

A crash is when the game terminates unexpectedly and closes, usually from a fatal error like an unhandled exception, leaving a stack trace at the failure point. A hang is when the game becomes unresponsive but keeps running, stuck without progressing, typically from a deadlock, infinite loop, or blocked thread, and on mobile a long hang is often surfaced as an ANR. A crash ends the process; a hang gets stuck in it.

What is an ANR and is it a crash?

An ANR (Application Not Responding) is a mobile OS signal that an app has become unresponsive for too long, it's a hang, not a crash. The app hasn't terminated; it's stuck, usually because the main thread is blocked by a long or deadlocked operation. The OS flags it as an ANR because the app isn't responding to input. So an ANR is the mobile manifestation of a hang, distinct from a crash where the process actually terminates.

Why is a hang harder to debug than a crash?

Because a hang is the program stuck rather than failed at a single point, so it often doesn't leave a clean stack trace the way a crash does. Diagnosing a hang means finding where the program got stuck, a deadlock, an infinite loop, or the main thread blocked on a long operation, which requires investigating concurrency and long-running operations. A crash, by contrast, usually hands you a specific failure line via its stack trace.

Crash vs Hang: What's the Difference?

Quick answer: A crash is when the game terminates unexpectedly; a hang is when it becomes unresponsive but keeps running, stuck without progressing. A crash leaves a stack trace; a hang points to a deadlock or blocked thread.

Crash and hang are two distinct ways a game can fail, one stops dead, the other gets stuck. They feel similar to players but have different causes and require different debugging. Here's the difference between a crash and a hang.

What a Crash Is

A crash is when the game terminates unexpectedly, the process ends and the game closes. It's caused by something fatal the program can't continue past, typically an unhandled exception or a memory access violation. The defining trait is termination: after a crash, the game is gone.

Crashes leave a clear forensic trail, a stack trace at the point of failure, which makes them diagnosable. Bugnet captures crashes automatically with symbolicated stack traces, so even an abrupt crash gives you a specific line and call chain to investigate.

What a Hang Is

A hang is when the game stops responding but keeps running, the process is alive, but it's stuck and not progressing, unresponsive to input. On mobile, a hang that lasts long enough is often surfaced by the OS as an ANR (Application Not Responding). The cause is usually a deadlock, an infinite loop, or a thread blocked on something that never completes.

Unlike a crash, a hang doesn't terminate, so it may not produce a clean stack trace at a single failure point. Diagnosing it means finding where the program got stuck, often around threading or a long-running operation that blocked the main thread.

Why the Distinction Matters

The distinction directs your debugging. A crash points to a fatal error with a stack trace to follow, often a quick lead. A hang points to a stuck state, a deadlock, infinite loop, or blocked main thread, which requires investigating concurrency and long operations, a different and often trickier diagnosis.

Both ruin the player's session, so both deserve attention. Bugnet captures crashes with stack traces and helps surface patterns in hangs and unresponsiveness. So treat crash and hang as distinct: a crash terminates with a trace, a hang freezes while running (an ANR on mobile), each requiring a different debugging approach.

A crash terminates the game (leaving a stack trace); a hang freezes it while still running (a deadlock or blocked thread, surfaced as an ANR on mobile). Each points at different causes and debugging.