Specified images.localPatterns should be an Array received $

Error message

Specified images.localPatterns should be an Array received ${typeof images.localPatterns}.
See more info here: https://nextjs.org/docs/messages/invalid-images-config

What it means

`images.localPatterns` controls which local URLs the image optimizer will fetch. It must be an array of `{ pathname, search }` glob-pattern objects. The guard at config.ts:653-658 rejects any truthy non-array value because the next step calls `.some()` / `.push()` on it. If left unset, Next.js seeds a default allowing all local paths.

Source

Thrown at packages/next/src/server/config.ts:655

      if (result.assetPrefix === '') {
        result.assetPrefix = result.basePath
      }
    }
  }

  if (result?.images) {
    const images: ImageConfig = result.images

    if (typeof images !== 'object') {
      throw new Error(
        `Specified images should be an object received ${typeof images}.\nSee more info here: https://nextjs.org/docs/messages/invalid-images-config`
      )
    }

    if (images.localPatterns) {
      if (!Array.isArray(images.localPatterns)) {
        throw new Error(
          `Specified images.localPatterns should be an Array received ${typeof images.localPatterns}.\nSee more info here: https://nextjs.org/docs/messages/invalid-images-config`
        )
      }
      // avoid double-pushing the same pattern if it already exists
      if (
        !images.localPatterns.some(
          (pattern) =>
            pattern.pathname === '/_next/static/media/**' &&
            pattern.search === ''
        )
      ) {
        // static import images are automatically allowed
        images.localPatterns.push({
          pathname: '/_next/static/media/**',
          search: '',
        })
      }
      if (

View on GitHub (pinned to 0ae8c72462)

Solutions

Wrap your pattern in an array: `localPatterns: [{ pathname: '/assets/**', search: '' }]`.
Confirm each entry has `pathname` (string glob) and optional `search` (string).
If you want all local paths, omit localPatterns entirely so Next.js applies the default.

Example fix

// before
module.exports = { images: { localPatterns: { pathname: '/assets/**' } } }
// after
module.exports = { images: { localPatterns: [{ pathname: '/assets/**', search: '' }] } }

Defensive patterns

Strategy: type-guard

Validate before calling

const lp = config.images?.localPatterns;
if (lp != null && !Array.isArray(lp)) throw new Error('images.localPatterns must be an array');
for (const p of lp ?? []) { if (typeof p.pathname !== 'string') throw new Error('each localPattern needs a pathname string'); }

Type guard

type LocalPattern = { pathname: string; search?: string };
function isLocalPatternsArray(v: unknown): v is LocalPattern[] {
  return Array.isArray(v) && v.every((p) => p && typeof (p as any).pathname === 'string');
}

Prevention

Always wrap individual patterns in an array literal in config.
Lint config files for `localPatterns:` followed by `{` instead of `[`.

When it happens

Trigger: Setting `images: { localPatterns: { pathname: '/assets/**' } }` (an object instead of an array), or `localPatterns: '/assets/**'` (a string).

Common situations: Migrating from `remotePatterns`/`domains` and assuming localPatterns takes a single object. Misreading docs and supplying one pattern object rather than an array of one.

Related errors

AI-assisted analysis of vercel/next.js@0ae8c72462 (2026-08-06). Data as JSON: /api/errors/cbccc8b642af7573. Report an issue: GitHub.