# SVG to ICO study
Experiment date 2026-10-26. CC0 original drawings.
Upload each of the six valid SVGs at https://filepetal.com/svg-to-ico/ with the 16/32/48/256 setting. Download the ICO; square.svg was also saved using 256 px only. Each multiple ICO contains four independently rendered PNG payloads, not four separate downloads. Reference PNG files here are extracted from actual ICO downloads, not additional tool export buttons. verification.json gives input/output bytes, dimensions, payload sizes, alpha bounds and full SHA256. SHA256SUMS.txt identifies the exact archived files.
Run generate-fixtures.py in an empty folder to recreate input SVGs. Parse the recorded ICOs with Pillow, or use Filepetal ICO to PNG to inspect each contained image. Browser PNG encoders can change file bytes. A matching reference hash identifies a file; it is not a universal quality test.
Wide/tall art is fitted without distortion or crop; unused square area remains clear. A painted white background stays white. Fine strokes can fade at small sizes. No background eraser, favicon site installation, manifest or automatic optical correction is provided. Five diagnostic inputs should produce an error and no stale result. One desktop browser tested; no physical phone, Windows shell or competitor conversion tested. Keep original SVG for editing.