Configure from Project Settings → Resolution → Codec .
Default: AV1 primary, H.264 fallback. Streampixel auto-falls-back to the secondary codec when a viewer’s browser or your UE version doesn’t support the primary.
Codec options Codec Quality at low bitrate Compatibility Notes AV1 ★ RecommendedBest Chrome desktop, modern hardware Highest quality per bit. Recommended primary codec for every use case. Requires UE 5.4+ on the encoder side. VP9 Good Chrome, Firefox, Edge Better quality than H.264 at the same bandwidth. Strong fallback for ArchViz / Digital Twin. H.264 Blocky Universal GPU-accelerated. Safe fallback for the broadest device reach. VP8 Average Universal CPU-decoded — older devices may struggle.
When fallback kicks in Scenario What happens Viewer on iPhone, AV1 primary iOS doesn’t decode AV1 → falls back to your fallback codec. Viewer on older Firefox, AV1 primary Firefox lacks AV1 → falls back. UE 5.3 or below, AV1 primary Encoder can’t produce AV1 → falls back globally.
AV1 only works on UE 5.4+. If you’re on an older version, set H.264 or VP9 as primary.
Recommended pairings AV1 is the recommended primary codec for every use case. Pick a fallback based on your audience.Use case Primary Fallback ArchViz / Digital Twin AV1 VP9 Chatbot / Avatar AV1 H.264 Games / Interactive AV1 H.264 Mixed devices, broad reach AV1 H.264
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Resolution settings Pair codec with the right resolution mode.
Performance tuning Hit your latency, FPS, and bitrate targets.
