PRG Pattern Explained Simply + Benefits for SEO

The PRG pattern is a variant of link masking. The abbreviation stands for “Post-Redirect-Get.” The method is used mainly in large online shops to avoid duplicate content or near-duplicate content and to save the Googlebot’s crawl budget.

This makes the PRG pattern an alternative to setting canonical tags, the attributes noindex and nofollow, and blocking pages in robots.txt. Sometimes these variants are also combined.

How the PRG pattern works

The core purpose of the PRG pattern is originally and primarily to prevent duplicate form submissions. After a form is submitted (POST), the server does not respond directly with content but instead redirects via HTTP 303 See Other (or 302 Found as a fallback) to a GET request. This way, a reload or the back button does not resend the form data – avoiding, for example, a duplicate order. Only on top of this is the pattern used in SEO as link masking.

In SEO use, the pattern is based on the following principle:

• Post: When a user clicks a filter link, a post request is sent to the server.
• Redirect: The server responds with a redirect (HTTP 303) to the source page.
• Get: Only in the third step does the get request occur, through which the target page is served.

What is decisive for the SEO benefit is that the Googlebot generally does not follow post forms. This has two advantages:

• No new URLs are created. This means there is no duplicate content that could have a negative effect.
• The PRG pattern prevents link power (“link juice”) from flowing off to unimportant filter URLs and keeps it concentrated on the crawlable, important links. At the same time, the link structure stays clearer.

Tips for search engine optimization (SEO)

The PRG pattern is used above all in large online shops. Especially with filter functions, it prevents the creation of countless URLs that lead to duplicate content and unnecessarily consume crawl budget.

Whether the method is applicable depends on technical prerequisites: the server-side programming language, the CMS and other factors. Web developers need a certain technical understanding (basic knowledge of HTML and CSS). It is best to outsource the HTML of the navigation instead of placing it in the source code; it can be loaded via AJAX.

The PRG pattern is also used for the back button on forms: because form data is not resent, the user experience improves.

For filtered product lists, the PRG pattern can be usefully combined with canonical tags and the noindex attribute: PRG keeps the masked filter targets out of crawling, while canonical/noindex cleanly consolidate the remaining, accessible variants. This keeps the crawl budget on the relevant pages.