{
  "schemaVersion": 1,
  "generatedAt": "2026-08-01T11:18:50.680Z",
  "benchmarkDate": "2026-08-01",
  "title": "Audio format size and browser compatibility benchmark",
  "fixture": {
    "description": "Deterministic synthetic multi-tone and low-level noise fixture generated by FFmpeg. It is designed for repeatability, not to represent every voice or music recording.",
    "durationSeconds": 60,
    "sampleRate": 48000,
    "channels": 2,
    "bitDepth": 16
  },
  "environment": {
    "ffmpeg": "ffmpeg version 2025-07-17-git-bc8d06d541-full_build-www.gyan.dev Copyright (c) 2000-2025 the FFmpeg developers",
    "platform": "win32 x64",
    "cpu": "AMD Ryzen 7 4800H with Radeon Graphics         ",
    "encodeRepeats": 3
  },
  "methodology": [
    "Generate one deterministic 60-second, 48 kHz, stereo, 16-bit PCM source fixture.",
    "Encode every variant three times with the listed FFmpeg codec and target bitrate.",
    "Measure final bytes, effective bitrate, and the median wall-clock encode time on one test host.",
    "Serve each produced file to current Playwright Chromium, Firefox, and WebKit engines and require loaded metadata from the real file.",
    "Treat browser results as a dated engine test, not a promise for every operating system, device, or vendor build."
  ],
  "results": [
    {
      "id": "wav-pcm",
      "label": "WAV PCM",
      "family": "WAV",
      "compression": "Lossless",
      "extension": "wav",
      "mimeType": "audio/wav",
      "targetKbps": null,
      "actualBytes": 11520078,
      "actualKbps": 1536,
      "percentOfWav": 100,
      "medianEncodeMs": 119.2,
      "codec": "pcm_s16le",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "flac",
      "label": "FLAC",
      "family": "FLAC",
      "compression": "Lossless",
      "extension": "flac",
      "mimeType": "audio/flac",
      "targetKbps": null,
      "actualBytes": 6495609,
      "actualKbps": 866.1,
      "percentOfWav": 56.4,
      "medianEncodeMs": 361.7,
      "codec": "flac",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "mp3-128",
      "label": "MP3 128 kbps",
      "family": "MP3",
      "compression": "Lossy",
      "extension": "mp3",
      "mimeType": "audio/mpeg",
      "targetKbps": 128,
      "actualBytes": 960812,
      "actualKbps": 128.1,
      "percentOfWav": 8.3,
      "medianEncodeMs": 971,
      "codec": "mp3",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "mp3-192",
      "label": "MP3 192 kbps",
      "family": "MP3",
      "compression": "Lossy",
      "extension": "mp3",
      "mimeType": "audio/mpeg",
      "targetKbps": 192,
      "actualBytes": 1441196,
      "actualKbps": 192.2,
      "percentOfWav": 12.5,
      "medianEncodeMs": 1024.7,
      "codec": "mp3",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "mp3-320",
      "label": "MP3 320 kbps",
      "family": "MP3",
      "compression": "Lossy",
      "extension": "mp3",
      "mimeType": "audio/mpeg",
      "targetKbps": 320,
      "actualBytes": 2401964,
      "actualKbps": 320.3,
      "percentOfWav": 20.9,
      "medianEncodeMs": 1059.4,
      "codec": "mp3",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "aac-128",
      "label": "AAC 128 kbps",
      "family": "AAC",
      "compression": "Lossy",
      "extension": "m4a",
      "mimeType": "audio/mp4; codecs=mp4a.40.2",
      "targetKbps": 128,
      "actualBytes": 974041,
      "actualKbps": 129.9,
      "percentOfWav": 8.5,
      "medianEncodeMs": 1744.2,
      "codec": "aac",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "aac-192",
      "label": "AAC 192 kbps",
      "family": "AAC",
      "compression": "Lossy",
      "extension": "m4a",
      "mimeType": "audio/mp4; codecs=mp4a.40.2",
      "targetKbps": 192,
      "actualBytes": 1453973,
      "actualKbps": 193.9,
      "percentOfWav": 12.6,
      "medianEncodeMs": 1944.7,
      "codec": "aac",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "aac-256",
      "label": "AAC 256 kbps",
      "family": "AAC",
      "compression": "Lossy",
      "extension": "m4a",
      "mimeType": "audio/mp4; codecs=mp4a.40.2",
      "targetKbps": 256,
      "actualBytes": 1935755,
      "actualKbps": 258.1,
      "percentOfWav": 16.8,
      "medianEncodeMs": 2038.9,
      "codec": "aac",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "vorbis-128",
      "label": "Ogg Vorbis 128 kbps",
      "family": "Ogg",
      "compression": "Lossy",
      "extension": "ogg",
      "mimeType": "audio/ogg; codecs=vorbis",
      "targetKbps": 128,
      "actualBytes": 710146,
      "actualKbps": 94.7,
      "percentOfWav": 6.2,
      "medianEncodeMs": 1042.3,
      "codec": "vorbis",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "vorbis-192",
      "label": "Ogg Vorbis 192 kbps",
      "family": "Ogg",
      "compression": "Lossy",
      "extension": "ogg",
      "mimeType": "audio/ogg; codecs=vorbis",
      "targetKbps": 192,
      "actualBytes": 1068064,
      "actualKbps": 142.4,
      "percentOfWav": 9.3,
      "medianEncodeMs": 1026.1,
      "codec": "vorbis",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "opus-64",
      "label": "Opus 64 kbps",
      "family": "Opus",
      "compression": "Lossy",
      "extension": "opus",
      "mimeType": "audio/ogg; codecs=opus",
      "targetKbps": 64,
      "actualBytes": 570964,
      "actualKbps": 76.1,
      "percentOfWav": 5,
      "medianEncodeMs": 594.3,
      "codec": "opus",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "opus-96",
      "label": "Opus 96 kbps",
      "family": "Opus",
      "compression": "Lossy",
      "extension": "opus",
      "mimeType": "audio/ogg; codecs=opus",
      "targetKbps": 96,
      "actualBytes": 735302,
      "actualKbps": 98,
      "percentOfWav": 6.4,
      "medianEncodeMs": 656.2,
      "codec": "opus",
      "sampleRate": 48000,
      "channels": 2
    },
    {
      "id": "opus-128",
      "label": "Opus 128 kbps",
      "family": "Opus",
      "compression": "Lossy",
      "extension": "opus",
      "mimeType": "audio/ogg; codecs=opus",
      "targetKbps": 128,
      "actualBytes": 930218,
      "actualKbps": 124,
      "percentOfWav": 8.1,
      "medianEncodeMs": 763.5,
      "codec": "opus",
      "sampleRate": 48000,
      "channels": 2
    }
  ],
  "browsers": [
    {
      "name": "Chromium",
      "version": "149.0.7827.55",
      "support": {
        "wav-pcm": {
          "canPlayType": "maybe",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "flac": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "mp3-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "mp3-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "mp3-320": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-256": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "vorbis-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "vorbis-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "opus-64": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60.01
        },
        "opus-96": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60.01
        },
        "opus-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60.01
        }
      }
    },
    {
      "name": "Firefox",
      "version": "151.0",
      "support": {
        "wav-pcm": {
          "canPlayType": "maybe",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "flac": {
          "canPlayType": "maybe",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "mp3-128": {
          "canPlayType": "maybe",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "mp3-192": {
          "canPlayType": "maybe",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "mp3-320": {
          "canPlayType": "maybe",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-256": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "vorbis-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "vorbis-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "opus-64": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "opus-96": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "opus-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        }
      }
    },
    {
      "name": "WebKit",
      "version": "26.5",
      "support": {
        "wav-pcm": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "flac": {
          "canPlayType": "probably",
          "ok": false,
          "reason": "timeout"
        },
        "mp3-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60.05
        },
        "mp3-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60.05
        },
        "mp3-320": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60.05
        },
        "aac-128": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-192": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "aac-256": {
          "canPlayType": "probably",
          "ok": true,
          "reason": "loadedmetadata",
          "duration": 60
        },
        "vorbis-128": {
          "canPlayType": "",
          "ok": false,
          "reason": "media-error-4"
        },
        "vorbis-192": {
          "canPlayType": "",
          "ok": false,
          "reason": "media-error-4"
        },
        "opus-64": {
          "canPlayType": "",
          "ok": false,
          "reason": "media-error-4"
        },
        "opus-96": {
          "canPlayType": "",
          "ok": false,
          "reason": "media-error-4"
        },
        "opus-128": {
          "canPlayType": "",
          "ok": false,
          "reason": "media-error-4"
        }
      }
    }
  ]
}