{
  "date": "2026-10-30",
  "measured_at_utc": "2026-10-30T12:21:21.160498+00:00",
  "scope": "12 actual offered AVIF downloads from six original synthetic PNG inputs in one desktop in-app browser; independent Pillow decoding. Reference PNGs are decoded actual AVIFs, not substitute output files. No competitor conversion, other browser or physical device test.",
  "comparison_reference": "Pillow decoding of original PNG, not a claim to preserve original container/metadata or pre-encode browser raster exactly",
  "pairs": [
    {
      "input": {
        "file": "tiny-opaque.png",
        "bytes": 69,
        "sha256": "ddcd5af5a63051c809cbd99aa47a385933be87f59bcb6b2b657d572e64f58cc2",
        "size": [
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          1
        ]
      },
      "output": {
        "file": "tiny-opaque-q60.avif",
        "bytes": 310,
        "sha256": "24d1fa42e7e74c3bd0b16228e5f590e4f5bd372a1a36a6ae504145e00fd6526b",
        "size": [
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          1
        ],
        "format": "AVIF",
        "frames": 1
      },
      "settings": {
        "mode": "lossy",
        "quality": 60,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
      },
      "independent_decode": {
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        "rgba_pixels_different": 1,
        "rgba_max_abs_error": 2,
        "alpha_max_abs_error": 0,
        "alpha_levels": [
          255
        ],
        "opaque_rgb_pixels_different": 1,
        "opaque_rgb_max_abs_error": 2,
        "opaque_rgb_mean_abs_error": 1.0,
        "reference_png": "tiny-opaque-q60.png"
      },
      "actual_browser_download": true,
      "byte_difference": 241
    },
    {
      "input": {
        "file": "color-edges.png",
        "bytes": 292,
        "sha256": "e5ee6272d37c405c1c8a932141d65fdf687d7f75a0ab3b146003c61a9c25f13d",
        "size": [
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        ]
      },
      "output": {
        "file": "color-edges-q40.avif",
        "bytes": 1975,
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        ],
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        "frames": 1
      },
      "settings": {
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        "quality": 40,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
      },
      "independent_decode": {
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        "rgba_pixels_different": 8384,
        "rgba_max_abs_error": 247,
        "alpha_max_abs_error": 0,
        "alpha_levels": [
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        ],
        "opaque_rgb_pixels_different": 8384,
        "opaque_rgb_max_abs_error": 247,
        "opaque_rgb_mean_abs_error": 68.35126217451798,
        "reference_png": "color-edges-q40.png"
      },
      "actual_browser_download": true,
      "byte_difference": 1683
    },
    {
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        "file": "color-edges.png",
        "bytes": 292,
        "sha256": "e5ee6272d37c405c1c8a932141d65fdf687d7f75a0ab3b146003c61a9c25f13d",
        "size": [
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        ]
      },
      "output": {
        "file": "color-edges-q80.avif",
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        "sha256": "737373bd24d26370261565769bba776f158fb11c10603b5fabb45a7ac037ddf9",
        "size": [
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        ],
        "format": "AVIF",
        "frames": 1
      },
      "settings": {
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        "quality": 80,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
      },
      "independent_decode": {
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        "rgba_pixels_different": 8367,
        "rgba_max_abs_error": 231,
        "alpha_max_abs_error": 0,
        "alpha_levels": [
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        ],
        "opaque_rgb_pixels_different": 8367,
        "opaque_rgb_max_abs_error": 231,
        "opaque_rgb_mean_abs_error": 67.64869807195389,
        "reference_png": "color-edges-q80.png"
      },
      "actual_browser_download": true,
      "byte_difference": 3637
    },
    {
      "input": {
        "file": "color-edges.png",
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        "sha256": "e5ee6272d37c405c1c8a932141d65fdf687d7f75a0ab3b146003c61a9c25f13d",
        "size": [
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        ]
      },
      "output": {
        "file": "color-edges-q100.avif",
        "bytes": 11210,
        "sha256": "10e6260533d7913a6c54243194fc5a9b42700c137f22f16f1de8d1eb35100de3",
        "size": [
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        "format": "AVIF",
        "frames": 1
      },
      "settings": {
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        "quality": 100,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
      },
      "independent_decode": {
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        "rgba_pixels_different": 8359,
        "rgba_max_abs_error": 221,
        "alpha_max_abs_error": 0,
        "alpha_levels": [
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        ],
        "opaque_rgb_pixels_different": 8359,
        "opaque_rgb_max_abs_error": 221,
        "opaque_rgb_mean_abs_error": 67.5365533691115,
        "reference_png": "color-edges-q100.png"
      },
      "actual_browser_download": true,
      "byte_difference": 10918
    },
    {
      "input": {
        "file": "color-edges.png",
        "bytes": 292,
        "sha256": "e5ee6272d37c405c1c8a932141d65fdf687d7f75a0ab3b146003c61a9c25f13d",
        "size": [
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        ]
      },
      "output": {
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        "bytes": 17658,
        "sha256": "41be36924aa20d4a89f9af4466a2f793837bd05c6aa7019cce1042436836d5e3",
        "size": [
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        "format": "AVIF",
        "frames": 1
      },
      "settings": {
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        "quality": 100,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
      },
      "independent_decode": {
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        "rgba_pixels_different": 0,
        "rgba_max_abs_error": 0,
        "alpha_max_abs_error": 0,
        "alpha_levels": [
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        ],
        "opaque_rgb_pixels_different": 0,
        "opaque_rgb_max_abs_error": 0,
        "opaque_rgb_mean_abs_error": 0.0,
        "reference_png": "color-edges-lossless.png"
      },
      "actual_browser_download": true,
      "byte_difference": 17366
    },
    {
      "input": {
        "file": "alpha-bands.png",
        "bytes": 219,
        "sha256": "26006319310b64864ddfce11f23a873c9687831cc42e66a571774541fe6587ea",
        "size": [
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        ]
      },
      "output": {
        "file": "alpha-bands-q60.avif",
        "bytes": 559,
        "sha256": "4a0772b908c26c62d6994acce38aded2bc5a5d52203d2f21d3aeca0b758404b7",
        "size": [
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        "format": "AVIF",
        "frames": 1
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      "settings": {
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        "quality": 60,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
      },
      "independent_decode": {
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        "rgba_pixels_different": 8385,
        "rgba_max_abs_error": 195,
        "alpha_max_abs_error": 0,
        "alpha_levels": [
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        ],
        "opaque_rgb_pixels_different": 2080,
        "opaque_rgb_max_abs_error": 1,
        "opaque_rgb_mean_abs_error": 0.6666666666666666,
        "reference_png": "alpha-bands-q60.png"
      },
      "actual_browser_download": true,
      "byte_difference": 340
    },
    {
      "input": {
        "file": "alpha-bands.png",
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        "sha256": "26006319310b64864ddfce11f23a873c9687831cc42e66a571774541fe6587ea",
        "size": [
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      "output": {
        "file": "alpha-bands-q100.avif",
        "bytes": 603,
        "sha256": "f0d03f5b0419ea63deddc4be06033a7fcc1810e82909cf3c83b5d63ec98a5354",
        "size": [
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        "format": "AVIF",
        "frames": 1
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        "quality": 100,
        "speed": 6,
        "encoder": "@jsquash/avif 2.1.1",
        "bitDepth_parameter": 8,
        "qualityAlpha_parameter": 100
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      "independent_decode": {
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        "rgba_pixels_different": 8385,
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        "alpha_max_abs_error": 0,
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        ],
        "opaque_rgb_pixels_different": 2080,
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      "actual_browser_download": true,
      "byte_difference": 384
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    {
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        "sha256": "26006319310b64864ddfce11f23a873c9687831cc42e66a571774541fe6587ea",
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      "output": {
        "file": "alpha-bands-lossless.avif",
        "bytes": 573,
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        "speed": 6,
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        "qualityAlpha_parameter": 100
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        "rgba_pixels_different": 6305,
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        "opaque_rgb_pixels_different": 0,
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      "actual_browser_download": true,
      "byte_difference": 354
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    {
      "input": {
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      "actual_browser_download": true,
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    {
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    {
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  ]
}