Next.js · sdk · fg-0304

next/image quality prop is ignored on Next.js 16 and direct /_next/image?q=90 requests return 400

An Image with quality={90} is served at q=75

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

Next.js 16 changed the default images.qualities from any value to only [75]. Unlisted quality values are snapped to the nearest allowed one, and the optimizer rejects unlisted q values.

Fix

List every quality you use in images.qualities.

Apply

// next.config.ts
export default { images: { qualities: [75, 90] } }

Affects: Next.js 16.0 and later

Sources

• https://nextjs.org/docs/app/guides/upgrading/version-16
• https://nextjs.org/docs/app/api-reference/components/image

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