Next.js Dynamic Route Error: How to Fix 'Path Does Not Match Page' with getStaticPaths & getStaticProps

Table of Contents#

1. Understanding the "Path Does Not Match Page" Error
2. Common Causes of the Error
3. Prerequisites
4. Step-by-Step Fix
5. Advanced Scenarios
6. Prevention Tips
7. Conclusion
8. References

Understanding the Error#

The "Path Does Not Match Page" error in Next.js typically appears during:

• Build time: When next build fails to pre-render a page because the path structure is invalid.
• Runtime: If a user navigates to a dynamically generated path that wasn’t pre-rendered and fallback is misconfigured (more on this later).

The error message itself is usually vague, but it boils down to a mismatch between:

• The dynamic route structure defined by your page filename (e.g., [slug].js, [category]/[post].js).
• The paths generated by getStaticPaths, which tell Next.js which URLs to pre-render.

Example Error Scenario#

Suppose you have a blog with a dynamic route pages/posts/[slug].js (to handle URLs like /posts/hello-world). If getStaticPaths returns a path with a parameter named id instead of slug, Next.js will throw the error because it expects a slug parameter to match the [slug].js filename.

Common Causes#

Here are the most frequent culprits:

1. Mismatched Parameter Names: The params object in getStaticPaths uses a key that doesn’t match the dynamic route’s filename (e.g., [slug].js expects slug, but you return id).

2. Incomplete Nested Route Params: For nested dynamic routes (e.g., [category]/[post].js), getStaticPaths is missing one or more required parameters (e.g., only returning post without category).

3. Trailing Slash Mismatch: A conflict between Next.js’s trailingSlash config and the paths generated (e.g., paths end with / when trailingSlash: false is set).

4. Invalid Characters in Slugs: Slugs with unencoded special characters (e.g., spaces, /, ?) can break path generation.

5. Fallback Misconfiguration: Setting fallback: false but not pre-rendering all possible paths, leading to 404s or runtime errors.

Prerequisites#

To follow this guide, you should:

• Have a basic understanding of Next.js Pages Router (we’ll focus on Pages Router; App Router uses generateStaticParams, but the core logic is similar).
• Be familiar with getStaticPaths and getStaticProps for static site generation (SSG).
• Have access to your project’s codebase and build logs.

Step-by-Step Fix#

Let’s resolve the error with a systematic approach. We’ll use a sample blog with a dynamic route as our case study.

Step 1: Verify the Dynamic Route Structure#

First, confirm your page’s filename matches the intended URL structure. Next.js uses the pages directory (or app for App Router) to define routes.

Example Mistake: If your filename is [slug].js but you want to use id as the parameter, rename the file to [id].js or update getStaticPaths to use slug (not id).

Step 2: Inspect getStaticPaths Output#

The getStaticPaths function returns an object with a paths array, where each entry defines a pre-rendered path. Log this output to debug mismatches.

Example: Logging getStaticPaths#

Add a console.log to getStaticPaths in your dynamic page:

// pages/posts/[slug].js  
export async function getStaticPaths() {  
  const paths = [  
    { params: { slug: "hello-world" } }, // Correct: matches [slug].js  
    { params: { id: "123" } }, // ❌ Error: parameter "id" doesn't match "slug"  
  ];  
 
  console.log("Generated paths:", paths); // Log to terminal  
 
  return { paths, fallback: false };  
}  

When you run next dev, check your terminal. You’ll see the invalid id parameter, confirming the mismatch.

Step 3: Ensure Params Match Route Segments#

For nested dynamic routes (e.g., [category]/[post].js), getStaticPaths must return all parameters defined in the filename.

Example: Nested Route Fix#

If your route is pages/[category]/[post].js, getStaticPaths must include both category and post:

// ❌ Incorrect: Missing "category" parameter  
export async function getStaticPaths() {  
  return {  
    paths: [{ params: { post: "nextjs-tips" } }], // Missing "category"  
    fallback: false,  
  };  
}  
 
// ✅ Correct: Includes both parameters  
export async function getStaticPaths() {  
  return {  
    paths: [  
      { params: { category: "tech", post: "nextjs-tips" } },  
      { params: { category: "design", post: "ui-trends" } },  
    ],  
    fallback: false,  
  };  
}  

Step 4: Handle Trailing Slashes#

Next.js’s trailingSlash config (in next.config.js) determines if URLs end with a /. Mismatched trailing slashes cause "Path Does Not Match Page" errors.

Example: trailingSlash Mismatch#

If next.config.js has:

// next.config.js  
module.exports = {  
  trailingSlash: true, // URLs must end with /  
};  

Your getStaticPaths must return paths with trailing slashes:

// ❌ Incorrect: Missing trailing slash  
{ params: { slug: "hello-world" } } // Generates /posts/hello-world (no /)  
 
// ✅ Correct: With trailing slash  
{ params: { slug: "hello-world/" } } // Generates /posts/hello-world/  

Conversely, if trailingSlash: false, omit the trailing slash.

Step 5: Validate Path Generation Logic#

If you fetch paths from an API or CMS (e.g., WordPress, Contentful), ensure the data source returns valid slugs. Common issues:

• Slugs with spaces (e.g., "hello world" instead of "hello-world").
• Slugs with / (e.g., "tech/nextjs" creates a nested path like /posts/tech/nextjs, which may require a catch-all route).

Fix: Sanitize Slugs#

Use a library like slugify to clean slugs before passing them to getStaticPaths:

import slugify from "slugify";  
 
export async function getStaticPaths() {  
  const posts = await fetch("https://api.example.com/posts").then(res => res.json());  
 
  const paths = posts.map((post) => ({  
    params: {  
      slug: slugify(post.title, { lower: true }), // Sanitizes "Hello World" → "hello-world"  
    },  
  }));  
 
  return { paths, fallback: false };  
}  

Step 6: Test with fallback#

The fallback option in getStaticPaths controls behavior for paths not pre-rendered at build time:

• fallback: false: Returns 404 for undefined paths (good for static content with known slugs).
• fallback: true: Serves a temporary "fallback" page and generates the path on the first request (use for large datasets).
• fallback: 'blocking': Server-renders the page on the first request (similar to getServerSideProps).

If fallback: false but you forgot to pre-render a path, users will see a 404 or runtime "Path Does Not Match Page" error. Use fallback: true or 'blocking' for dynamic content with unknown slugs.

Advanced Scenarios#

Nested Dynamic Routes#

For routes like pages/[author]/[post]/[comment].js, getStaticPaths must include all three parameters:

export async function getStaticPaths() {  
  return {  
    paths: [  
      {  
        params: {  
          author: "john-doe",  
          post: "nextjs-guide",  
          comment: "123", // All three parameters required  
        },  
      },  
    ],  
    fallback: "blocking",  
  };  
}  

Catch-All Routes ([...slug].js)#

Catch-all routes (e.g., pages/products/[...slug].js) match nested paths like /products/electronics/phone. Here, slug is an array of route segments:

// ✅ Correct for [...slug].js  
export async function getStaticPaths() {  
  return {  
    paths: [  
      { params: { slug: ["electronics", "phone"] } }, // Matches /products/electronics/phone  
      { params: { slug: ["clothing", "shirt"] } }, // Matches /products/clothing/shirt  
    ],  
    fallback: true,  
  };  
}  

Optional Catch-All Routes ([[...slug]].js)#

Optional catch-alls (note the double brackets) match the root path and nested paths. For pages/products/[[...slug]].js, valid paths include /products (empty array) and /products/electronics:

export async function getStaticPaths() {  
  return {  
    paths: [  
      { params: { slug: [] } }, // Matches /products  
      { params: { slug: ["electronics"] } }, // Matches /products/electronics  
    ],  
    fallback: false,  
  };  
}  

Prevention Tips#

1. Use TypeScript
   Type the params object in getStaticPaths to catch mismatches early:

   // pages/posts/[slug].tsx  
   export async function getStaticPaths() {  
     const paths: { params: { slug: string } }[] = [  
       { params: { slug: "hello-world" } },  
     ];  
     return { paths, fallback: false };  
   }  

2. Unit Test getStaticPaths
   Write tests to validate that getStaticPaths returns paths with the correct structure. Use tools like Jest:

   import { getStaticPaths } from "../pages/posts/[slug]";  
    
   test("getStaticPaths returns valid slug params", async () => {  
     const result = await getStaticPaths();  
     result.paths.forEach((path) => {  
       expect(path.params).toHaveProperty("slug"); // Ensure "slug" exists  
       expect(typeof path.params.slug).toBe("string"); // Ensure slug is a string  
     });  
   });  

3. Debug Build Output
   Use next build --debug to log all pre-rendered paths. Check for unexpected URLs or missing parameters.

4. Validate Data Sources
   If fetching paths from an API, add checks to ensure slugs are valid (no spaces, special characters, or leading/trailing slashes).

Conclusion#

The "Path Does Not Match Page" error in Next.js is almost always caused by a mismatch between your dynamic route’s filename and the params returned by getStaticPaths. By:

• Verifying your route structure,
• Inspecting getStaticPaths output,
• Ensuring parameters match route segments,
• Handling trailing slashes,

you can resolve the error and ensure smooth static generation. For advanced use cases like nested or catch-all routes, double-check that all required parameters are included.

References#

• Next.js Dynamic Routes Documentation
• getStaticPaths API Reference
• trailingSlash Configuration
• Catch-All Routes