Tractor 

¿Qué es un rastreador?

A crawler (spider, web spider, or web crawler) is an automated software program, also called a bot, used by search engines to discover and index webpages on the internet.

How Crawlers Work

Bloggers who want to appear on search results pages should understand how web crawlers work. Below is a simplified overview of how they operate.

1 Starting Point

Crawlers begin with a list of known URLs. These URLs are called seed URLs and usually point to popular websites and pages on the web. 

2 Fetching

The crawler visits each URL in the list. However, before crawling a site, the crawler checks the site’s robots.txt file to check whether the blogger has set rules to specify how crawlers should crawl their site. 

Search engine crawlers typically obey the robots.txt rules. They then visit the pages they can crawl to retrieve their HTML content. 

3 Parsing

The crawler then proceeds to parse the HTML data. That means it breaks the HTML data into its individual components and extracts the relevant information on the page, including its text, links, metadata, images, and other elements.

This allows the crawler to understand what the webpage is about. The crawler also takes note of the links on the page and adds them to the list of URLs to crawl. The crawler would later follow these links to discover the new pages on those sites. 

4 Indexing

The crawler stores the information gathered from the crawled pages in a database called an índice. When a visitor enters a search term into the search engine, the search engine selects relevant content from the index and shows it to the visitor.

5 Recrawling

The crawler will periodically check the webpages in its index to see if they have been updated since its last visit. If they have, it will recrawl them and update its index.

The rate at which the crawler revisits a URL depends on several factors, including how important the webpage is, how frequently it is updated, the server response time, and the crawl budget allocated by the search engine.

Importance of Web Crawlers

Crawlers are crucial for discovering the webpages displayed on search results pages. The process of visiting a page and fetching its content using a crawler is called crawling, and the ability of a crawler to discover and crawl a webpage is called crawlability.

Crawling itself is the first step for webpages displayed on search results pages. Specifically, search is a three-step process that includes:

• Crawling 
• Indexing 
• Serving

Content needs to be crawled before it can be indexed, and it needs to be indexed before it can be served on search results pages. This means that content not crawled cannot be indexed and served on search results pages.

Overall, if you want content on search results pages, then make sure the content can be crawled. Otherwise, it will not get to the search results page, no matter how good it is.

Good Crawlers vs. Bad Crawlers

Bloggers typically differentiate between good and bad crawlers. Good crawlers are crawlers that are helpful to a site. For example, search engine crawlers like Googlebot y Bingbot are typically considered good bots.

On the other hand, bad crawlers are web crawlers that steal data and disrupt or harm the website. What is considered a bad bot can vary from site to site. Some bloggers even categorize otherwise good bots that disobey robots.txt rules or scrape content as bad bots. 

Web Crawler Best Practices

Search engines rely on efficient crawling to index and present your site on search results pages. To ensure search engines can crawl your site and content, we recommend following the best practices below.

1 Use a Clean URL Structure

Use descriptive URLs that are short and free of unnecessary parameters. For example, a URL like https://example.com/yoga/best-yoga-poses is good as it helps crawlers understand the page’s content and its hierarchy. 

2 Optimize Your Page Speed

Su page speed is the time it takes your pages to load. Fast-loading pages are more likely to be crawled and indexed regularly than slow-loading ones. Slow-loading pages, for their part, signal to search engines that you are experiencing server issues. 

This will affect your crawlability as the search engine would reduce your crawl budget in response, which could cause the crawler to visit your site and pages less often. You should consider this page speed optimization guide to ensure your pages load quickly.

3 Create a robots.txt File

Your robots.txt file guides crawlers on which parts of your site should or should not be crawled. So, be sure to create one that prevents crawlers from accessing sensitive areas of your site.

It is essential to update this file frequently. You should also keep it error-free to prevent crawlers from crawling the wrong pages or not crawling the pages that you want them to crawl.

4 Generate an XML Sitemap

Un mapa del sitio XML provides a structured list of all important pages on your site. Crawlers usually access it to discover the important pages on your site. So, ensure to create one and keep it updated with the posts and pages you want on search results pages. 

However, it is crucial to state that crawlers can find your pages without an XML sitemap. The sitemap only acts as a guide and is not the only method of discovering your webpages. 

5 Implement Internal Links

Crawlers follow links to find your webpages. This includes inbound links that point to your site from other sites and internal links that originate from and point to another page on your site.

Ensure to implement an internal linking strategy to ensure that crawlers can find your pages and understand the relationship between different pages on your site. 

6 Minimize Broken Links

Broken links prevent crawlers from navigating your site and discovering and crawling your pages. They also signal to search engines that your site is poorly maintained. 

This will affect your crawlability. Some search engines will even penalize your site when you have many broken links. This will affect your SEO and may cause your rankings to drop on search results pages. 

7 Avoid Excessive Redirects

While redirects are useful, excessive redirects can confuse crawlers and slow down your page speed. Crawlers will also stop following a link after a few redirects, which will leave the page uncrawled. 

Make sure to use redirects only when necessary and avoid redirect chains. The best redirect is one that goes from the old URL to the new one. If your redirect is any longer, ensure it is not unnecessarily long and does not become a redirect chain.