Web Image Formats Research

Transparent, reproducible benchmarks comparing modern image formats for the web — AVIF, JPEG XL, WebP, and JPEG — using perceptual quality metrics.

InteractivePlotly

Research Report

Interactive figures and analysis results from encoding studies. Compare formats across quality, file size, and encoding speed.

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StarlightDiátaxis

Documentation

Tutorials, how-to guides, API reference, and background explanations for running and extending the research.

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GitHub

Source Code

Browse the source, study configurations, and CI workflows. Contributions and issue reports are welcome.

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Key Findings

A preview of results from the format comparison study — two metrics, one story with a twist.

SSIMULACRA2 vs bits per pixel: AVIF and JPEG XL both clearly outperform WebP and JPEG across all quality levels.
SSIMULACRA2 metric. AVIF and JPEG XL deliver comparable perceptual quality at significantly lower file sizes than WebP and JPEG.
Butteraugli vs bits per pixel: JPEG XL consistently outperforms AVIF, while both outperform WebP and JPEG.
Butteraugli metric. Under this distortion model JPEG XL consistently edges ahead of AVIF — a different verdict than SSIMULACRA2, highlighting how metric choice matters.

About This Project