Next.js 14, 15, 16 向けの追加料金なし画像最適化

// smallpict-loader.ts
export default function smallPictLoader({ src, width, quality }: { src: string; width: number; quality?: number }) {
  const params = new URLSearchParams({
    url: src,
    w: width.toString(),
    q: (quality || 80).toString(),
    f: 'auto'
  });
  return `https://cdn.smallpict.app/v1/optimize?${params.toString()}`;
}

// next.config.ts
import type { NextConfig } from 'next';
const nextConfig: NextConfig = {
  images: {
    loader: 'custom',
    loaderFile: './smallpict-loader.ts',
  },
};
export default nextConfig;