Why Page Speed is the #1 Ranking Factor in Google

Page Speed is the most important part of onsite optimization

If Google can’t spider your site they can’t find all the pages, and if they can’t find the page it doesn’t matter how good the content or SEO is because they’ll never see the page.

So being able to find the page is the most important part of the game because if they can’t find the page you can’t rank the page.

1. Crawl Efficiency and Indexation

Crawl Budget: Google allocates a specific crawl budget to each website, which is the number of pages Googlebot will crawl within a given timeframe. Slow page speeds can lead to a lower crawl budget, meaning fewer pages from your site get indexed.
Crawl Rate: If your site is slow, Googlebot will reduce its crawl rate to avoid overloading your server, leading to less frequent updates and potentially missing new or updated content.
Crawl Depth: Slow sites may not have their deeper pages crawled and indexed, affecting the visibility of those pages in search results.
Crawl Timeout: Googlebot has a limited amount of time to crawl each page. If your page doesn’t load quickly, Googlebot may abandon the crawl, leaving your page unindexed.

And while other things can affect them being able to find a page like bad links, JavaScript and bad code page speed stands out among those other things because it takes it three steps further.

2. Core Web Vitals

In May 2021, Google introduced Core Web Vitals, emphasizing the importance of user experience metrics in their ranking algorithm. This initiative highlights Google's commitment to rewarding websites that deliver content quickly and efficiently.
During a Google Webmaster Hangout, John Mueller explained that Google aims to provide the best possible user experience. As part of this strategy, they have begun to reward sites that optimize content delivery for speed and efficiency.
By 2022, John Mueller reaffirmed that page speed remains a critical factor in SEO. However, the focus has shifted from page speed as a standalone metric to the more comprehensive Core Web Vitals, which encompass various elements of user experience that must be optimized.
One of the key components of Core Web Vitals is Largest Content Paint (LCP). Google considers an LCP of over 2.5 seconds as needing improvement. LCP measures the time it takes to render the largest content element visible in the viewport.

In essence, Google is clearly stating that your site should achieve an LCP under 2.5 seconds to avoid performance issues. If your largest content element takes longer than this to load, it indicates a problem that could negatively impact your SEO rankings.

Thus, optimizing for Core Web Vitals, particularly LCP, is crucial for maintaining and improving search visibility. This focus aligns directly with Google's ongoing effort to enhance user satisfaction through faster, more responsive web experiences.

So page speed affects crawlability and Core Web Vitals but it also takes that a bit further with User Experience and Engagement Metrics.

3. User Experience and Engagement Metrics

Bounce Rate: Google’s own research indicates that bounce rate increases dramatically as page load time increases. Specifically, bounce rate almost triples when page load time exceeds three seconds. This means users are more likely to leave your site before it fully loads, negatively impacting user engagement metrics that Google considers in its ranking algorithm.
Session Duration: Can impact search engine rankings. Search engines like Google look at user engagement as a signal when ranking websites because they want to send people to websites that provide a great experience. A higher session duration suggests that your site is providing value.

Now while page speed affects the single most important thing which is Google being able to find the page, as well Core Web Vitals, and the users experience and engagement it also affects conversions and revenue.

4. Direct Impact on Conversions and Revenue

Amazon: Found that for every 100 milliseconds of improved load time, there was a 1% increase in sales.
Mobify: Reported a 1.11% increase in sales for every 100 milliseconds improvement.
Walmart: Saw a 2% increase in conversion rate for every one-second improvement in page load time.
Cook: Observed a 7% increase in conversions for every 850 milliseconds improvement in load time.

5. Official Statements and Recommendations

Google's Web Performance Recommendations: Google recommends that the First Content Paint (FCP) should occur within 1 second or less. This is a clear indicator that Google values fast loading times as part of its overall assessment of page quality.
John Mueller’s Statements: Google's John Mueller has explicitly stated that high response times can severely limit the number of URLs Google will crawl from a site. He emphasizes the need for fast and responsive servers to ensure optimal crawling and indexing.

6. Technical SEO Considerations

Crawl Budget Management: Ensuring a fast site helps maximize your crawl budget, allowing more of your site to be indexed regularly.
Server Responsiveness: A fast server not only improves user experience but also ensures that Googlebot can efficiently crawl your site, which can positively impact your rankings.

7. Empirical Evidence and Industry Studies

Google’s Research: Multiple studies and tests conducted by Google underline the importance of page speed. Sites with faster load times not only rank higher but also tend to have better user engagement metrics, which are critical for SEO.
Industry Case Studies: The examples from Amazon, Mobify, Walmart, and Cook provide tangible evidence of how page speed improvements can lead to better business outcomes, which Google’s algorithms are likely to reward.

Conclusion

So we agree that if Google can’t spider your site they can’t find all the pages, and if they can’t find the page it doesn’t matter how good the content or SEO is because they’ll never see the page.