Next.js Image Optimization in 2026: next/image v4, AVIF by Default, and the Config Changes Teams Miss This article was written with the assistance of AI, under human supervision and review. Most Next.js image performance problems in 2026 stem from teams upgrading to v4 without understanding the default format switch to AVIF and the breaking configuration changes that silently degrade production pipelines. The next/image component shipped automatic WebP conversion in v3, but v4 p...