The Newbies Guide to Block URLs in a Robots.txt File

If you’ve ever wondered how to keep certain pages of your website hidden from search engines, you’re in the right place. Whether you want to stop duplicate pages from appearing in search results, prevent search engines from indexing private content, or optimize your crawl budget, using a robots.txt file is an essential tool in your SEO toolkit.

This guide is designed for beginners who want to learn how to block URLs using a robots.txt file without causing SEO issues. We’ll cover everything from what a robots.txt file is, how it works, and step-by-step instructions to set it up correctly. By the end of this post, you’ll have a solid understanding of how to block URLs from search engines safely.

What Is a Robots.txt File?

A robots.txt file is a simple text file placed in the root directory of a website. It contains directives that tell search engine crawlers (like Googlebot, Bingbot, and others) which pages or sections of your website they are allowed—or not allowed—to crawl.

Why Use a Robots.txt File?

Here are some of the most common reasons why website owners use a robots.txt file:

Prevent search engines from crawling duplicate content (such as printer-friendly pages or session-based URLs)
Hide private or sensitive pages (e.g., admin pages, login pages, or internal reports)
Stop search engines from wasting crawl budget on unimportant pages
Prevent image, PDF, or resource file indexing
Avoid indexing low-value pages like internal search results

How Search Engines Read Robots.txt

Before blocking URLs, it’s important to understand how search engines interpret the robots.txt file.

Key Components of a Robots.txt File

A robots.txt file consists of two main directives:

User-agent – Specifies which search engine crawler the rule applies to (e.g., Googlebot, Bingbot, or * for all bots).
Disallow – Instructs crawlers not to access specific URLs or directories.

Example of a simple robots.txt file:

User-agent: *
Disallow: /private-folder/

This tells all search engines not to crawl anything within the /private-folder/ directory.

Important Notes:

Robots.txt does not prevent indexing completely – If a page is already indexed or linked externally, it may still appear in search results. To ensure a page is not indexed, use the noindex meta tag instead.
Not all bots respect robots.txt – Malicious bots and scrapers might ignore it.
Google does not support noindex in robots.txt – Previously, some webmasters used Disallow: /page/ combined with Noindex, but Google no longer follows this method.

How to Block URLs in a Robots.txt File

Now, let’s go through various ways to block URLs using robots.txt.

1. Block an Entire Website

If you want to block your entire website from being crawled by search engines (e.g., during development), use:

User-agent: *
Disallow: /

2. Block a Specific Page

If you only want to prevent crawlers from accessing a single page, use:

User-agent: *
Disallow: /example-page.html

3. Block a Folder or Directory

To stop search engines from crawling an entire folder and its contents:

User-agent: *
Disallow: /private-folder/

4. Block a Specific Search Engine

If you only want to block Googlebot but allow others:

User-agent: Googlebot
Disallow: /

5. Block URLs with a Certain File Type

If you want to stop search engines from indexing all PDFs or other file types:

User-agent: *
Disallow: /*.pdf$

6. Block URLs with Query Parameters

If you have URLs with parameters (e.g., ?search=query), block them with:

User-agent: *
Disallow: /*?

7. Allow Crawling of Specific Files Inside a Blocked Folder

If you block a directory but want to allow one file:

User-agent: *
Disallow: /private-folder/
Allow: /private-folder/allowed-page.html

Where to Place the Robots.txt File

For robots.txt to work, it must be placed in the root directory of your website. It should be accessible at:

https://yourwebsite.com/robots.txt

If it’s not in the correct location, search engines won’t find or follow it.

Best Practices for Using Robots.txt

Be Careful When Blocking URLs – Avoid accidentally blocking important content (e.g., product pages or blog posts).
Test Your Robots.txt File – Use Google’s robots.txt tester in Google Search Console.
Use noindex for Stronger Control – If you want to ensure a page is not indexed, add noindex meta tags to the page instead.
Do Not Block JavaScript and CSS Files – Blocking these can harm SEO and prevent Google from rendering your site properly.
Regularly Review and Update – As your website grows, update your robots.txt to reflect any new changes.

Common Mistakes to Avoid

Accidentally blocking the entire website (Disallow: / without realizing it)
Blocking login pages instead of using authentication security
Relying on robots.txt to protect sensitive data (it doesn’t)
Blocking CSS and JavaScript files that search engines need to render your site properly

Conclusion

A robots.txt file is an essential tool for managing how search engines interact with your website. When used correctly, it helps improve crawl efficiency, protect sensitive areas, and optimize SEO. However, misusing robots.txt can cause severe SEO issues, so it’s important to follow best practices.

If you’re just starting out, take time to experiment with small changes and test them using Google’s tools. Over time, you’ll become more confident in managing search engine crawlers effectively.

For expert SEO and website optimization services, Upmax Creative is here to help. Need assistance? Contact us today!