Go: What is the difference between log.Fatal and log.Panic?

log.Fatal — logs and exits. log.Panic — logs and panics.

log.Fatal:

• Calls os.Exit(1).
• Deferred functions NOT executed.

1log.Fatal("Failed")
2// Deferred functions won't run

log.Panic:

• Calls panic().
• Deferred functions ARE executed.

1log.Panic("Failed")
2// Deferred functions run
3// Can recover

When to use log.Fatal:

• Startup failures.

When to use log.Panic:

• Errors requiring cleanup.

Common mistakes:

• Using log.Fatal when cleanup needed.
• Using log.Panic without recover().
• Forgetting log.Fatal skips deferred functions.
• Using either for normal error handling.
• Using log.Fatal in goroutines.