WAV, OGG or MP3: which format should game sound effects ship in?
Ship uncompressed WAV and let the engine compress once. Unity and Unreal re-encode on import, so a compressed source is compressed twice.
- Unity and Unreal re-encode audio at build time, whatever you import
- A compressed source gets compressed twice and clicks are where you hear it
- MP3 encoder padding breaks gapless loops; Vorbis and WAV do not
Should game sound effects be WAV, OGG or MP3?
Ship WAV to the engine. Unity and Unreal both re-encode audio at build time using their own settings, so whatever you import is compressed again on the way out. Importing an already-compressed file means the artefacts of the first encode are fed into the second, and on short transient sounds such as interface clicks, gun shots and impacts that is audible as a smeared or hollow attack. Uncompressed WAV lets the engine make that decision exactly once.
Does the WAV file size matter in the shipped game?
No, because the WAV is not what ships. The importer converts it to the engine's chosen format, so the size that matters is the compressed one in the build, not the source in your project folder. A project with 500 WAV files is a large repository and a normal-sized game.
Why not MP3?
Beyond the double-encode problem, MP3 adds encoder delay and padding at the start and end of a file. That silence is baked in, so a sound intended to loop seamlessly gets a gap on every repeat, and a sound intended to fire on a frame arrives late. Vorbis, which is what OGG normally carries and what Unity uses by default, does not have that problem, and WAV certainly does not.
When is a compressed file the right thing to import?
When nothing downstream is going to re-encode it: a web build loading audio directly, an engine or middleware configured to pass the file through untouched, or a long music bed where the size of the source genuinely matters. The rule is not that compression is bad, it is that it should happen once.
What sample rate and bit depth should game sound effects be?
44.1 kHz, 16-bit is the safe default and is what almost all game audio ships at. 48 kHz is common in video-led pipelines and is fine if the whole project is consistent. Going to 24-bit for a finished sound effect buys headroom you already spent in production; the place 24-bit earns its size is while recording and editing, not in the file you hand the engine.
What should I set on the Unity importer?
For short effects, Load Type: Decompress On Load, so the clip is not decoded on the frame it plays. Force To Mono for anything positional, since a 3D sound is panned by the engine and a stereo source both doubles the memory and fights the spatialiser. Leave the compression format at Vorbis for most things and use PCM for very short, very frequent sounds where decode cost matters more than size.
Every pack here ships as uncompressed 44.1 kHz 16-bit WAV for exactly this reason. Take 251 of them free and run them through your own importer.