Salesforce B2C Commerce 24.7 > Developing Your Site > Site Performance > Techniques for Improving Site Performance

404 Errors and 404 Pages

A site containing missing pages, images, JavaScript, or CSS files, can result in HTTP 404 error responses. To resolve these errors, you can use a link crawler to find broken links or missing images on any site pages.

Note: We recommend that you use link crawler tools during non-peak times.

You can also use browser developer tools to identify missing objects on pages that are responding to your browser with a 404 error.

No 404 error messages appear to shoppers for missing JavaScript or a missing include. However, error messages are generated and can affect system performance. We do not cache 404 responses by default. When 404 error response caching is not enabled, the system must request the asset each time a page is requested, resulting in the server having to work harder to respond to each page request. With administrator access, you can enable 404 error response caching for either static or dynamic content using feature switches available in Business Manager.

When using the 404 error response caching feature switches, keep the following in mind:

When using 404 caching for dynamic content, make sure to use the 404 response code when appropriate. For example, converting a sporadic 500 response to a 404 response can result in the undesirable effect of the web tier caching the response.
Be mindful of any content you included in 404 pages. We recommend that you avoid personalized content in 404 pages, as these pages can get cached and potentially displayed to many shoppers.

Note: New realms created after September 15th 2020 have 404 caching enabled by default. Administrators can disable 404 error response caching using feature switches in Business Manager.

When a shopper searches for an item that doesn't exist, they might also receive a 404 error page. This type of error typically results in the shopper seeing a generic 404 page not found message instead of the storefront. Receiving 404 pages can adversely affect the selling potential of a site. To help draw customers back to the shopping experience, we recommend customizing your 404 pages. For example, you can try adding the following to 404 pages:

Informational message―Add a message explaining that the page the customer is looking for can't be found.
Merchandising―Add top featured products, previously viewed products, or recently searched for products.
Search―Add a search box enabling the customer to search for a new product.
Sitemap―Add a sitemap that enables the customer to return to the site and continue shopping.