[b1ink0]

Sets the default AVIF quality to 74 in WP_Image_Editor::get_default_quality() and wp_get_image_encode_quality(). AVIF previously used the default of 82, which gives AVIF files only about 7% to 9% smaller than JPEG 82.

At 74, AVIF matches JPEG 82 on 83% (GD), 85% (Imagick) and 97% (browser) of generated images, at a median 72% to 76% of the JPEG 82 file size. The method and data are in the Trac ticket.

Trac ticket: https://core.trac.wordpress.org/ticket/66677

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: Drafting the patch, unit tests and ticket text, and running the benchmark. The chosen value and the final code were reviewed by me.

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This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

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[b1ink0]

cc: @adamsilverstein

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