# AN-2026-0715: Next.js 16 (Oct 21, 2025) next/image defaults: images.qualities only [75] (other q values get 400), local IPs blocked, 3 redirects max, minimumCacheTTL 4 h

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- id: AN-2026-0715 (version 1; cite https://breakwire.org/claim/AN-2026-0715/v/1)
- kind: breaking · status: active · review: editor
- source: <https://nextjs.org/docs/app/guides/upgrading/version-16#:~:text=Local%20Images%20with%20Query%20Strings>
- more sources: <https://github.com/vercel/next.js/blob/4e5335a00314be7fbb2aace5e9be56a88e64e5a8/packages/next/src/server/image-optimizer.ts>
- event date: 2025-10-21
- services: nextjs
- affected: npm:next >=16
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. Next.js 16 upgrade guide (opened 2026-11-03), next/image changes (all marked breaking): images.qualities now defaults to only [75]; a quality prop not in the list is coerced to the closest allowed value, and direct /_next/image requests with an unsupported q return 400.  [✓0 ✗0]
1. Local image sources with query strings now need images.localPatterns.search; local IP optimization is blocked unless images.dangerouslyAllowLocalIP is true (private networks only); images.maximumRedirects defaults to 3 instead of unlimited; images.minimumCacheTTL default went from 60 seconds to 4 hours (14400 s); 16 was removed from the default images.imageSizes.  [✓0 ✗0]
2. In next@16.4.5 (packages/next/src/server/image-optimizer.ts) an unsupported quality is rejected with: "q" parameter (quality) of <q> is not allowed.  [✓0 ✗0]

## Fix
```text
Set images.qualities (e.g. [50, 75, 100]) for every quality you request; add localPatterns with search for local images with query strings; set dangerouslyAllowLocalIP only for private networks, maximumRedirects and minimumCacheTTL: 60 if you depended on the old behavior.
```

## Error signatures
- substring: `parameter (quality) of` (next@16.4.5 image-optimizer.ts; full text "q" parameter (quality) of <q> is not allowed)

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0715/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary source opened 2026-10-28