Google: Focus On Field Data For Core Web Vitals via @sejournal, @MattGSouthern

Google stresses the importance of using actual user data to assess Core Web Vitals instead of relying only on lab data from tools like PageSpeed Insights (PSI) and Lighthouse.

This reminder comes as the company prepares to update the throttling settings in PSI. These updates are expected to increase the performance scores of websites in Lighthouse.

Field Data vs. Lab Data

Core Web Vitals measure a website’s performance in terms of loading speed, interactivity, and visual stability from the user’s perspective.

Field data shows users’ actual experiences, while lab data comes from tests done in controlled environments using tools like Lighthouse.

Barry Pollard, a Web Performance Developer Advocate at Google, recently emphasized focusing on field data.

In a LinkedIn post, he stated:

“You should concentrate on your field Core Web Vitals (the top part of PageSpeed Insights), and only use the lab Lighthouse Score as a very rough guide of whether Lighthouse has recommendations to improve performance or not…

The Lighthouse Score is best for comparing two tests made on the same Lighthouse (e.g. to test and compare fixes).

Performance IS—and hence LH Scores also ARE—highly variable. LH is particularly affected by where it is run from (PSI, DevTools, CI…), but also on the lots of other factors.

Lighthouse is a GREAT tool but it also can only test some things, under certain conditions.

So while it’s great to see people interested in improving webperf, make sure you’re doing just that (improve performance) and not just improving the score”

Upcoming Changes To PageSpeed Insights

Pollard discussed user concerns about PageSpeed Insights’s slow servers, which can cause Lighthouse tests to take longer than expected.

To fix this, Google is changing the throttling settings in PageSpeed Insights, which should lead to better performance scores when the update is released in the coming weeks.

These changes will affect both the web interface and the API but will not impact other versions of Lighthouse.

However, Pollard  reminds users that  “a score of 100 doesn’t mean perfect; it just means Lighthouse can’t help anymore.”

Goodhart’s Law & Web Performance

Pollard referenced Goodhart’s Law, which says that when a measure becomes a goal, it stops being a good measure.

In the web performance context, focusing only on improving Lighthouse scores may not improve actual user experience.

Lighthouse is a helpful tool, but it can only assess certain aspects of performance in specific situations.

Alon Kochba, Web Performance and Software Engineer at Wix, added context to the update, stating:

“Lighthouse scores may not be the most important – but this is a big deal for Lighthouse scores in PageSpeed Insights.

4x -> 1.2x CPU throttling for Mobile device simulation, which was way off for quite a while.”

Lighthouse scores may not be the most important – but this is a big deal for Lighthouse scores in PageSpeed Insights.

4x -> 1.2x CPU throttling for Mobile device simulation, which was way off for quite a while. https://t.co/ZLrwsDQGmO

— Alon Kochba (@alonkochba) December 6, 2024

Key Takeaway: Prioritize User Experience

As the update rolls out, website owners and developers should focus on user experience using field data for Core Web Vitals.

While Lighthouse scores can help find areas for improvement, they shouldn’t be the only goal.

Google encourages creating websites that load quickly, respond well, and are visually stable.

Featured Image: GoodStudio/Shutterstock

Google Uses About 40 Signals To Determine Canonical URLs via @sejournal, @MattGSouthern

In a recent episode of Google’s Search Off the Record podcast, Allan Scott from the “Dups” team explained how Google decides which URL to consider as the main one when there are duplicate pages.

He revealed that Google looks at about 40 different signals to pick the main URL from a group of similar pages.

Around 40 Signals For Canonical URL Selection

Duplicate content is a common problem for search engines because many websites have multiple pages with the same or similar content.

To solve this, Google uses a process called canonicalization. This process allows Google to pick one URL as the main version to index and show in search results.

Google has discussed the importance of using signals like rel=”canonical” tags, sitemaps, and 301 redirects for canonicalization. However, the number of signals involved in this process is more than you may expect.

Scott revealed during the podcast:

“I’m not sure what the exact number is right now because it goes up and down, but I suspect it’s somewhere in the neighborhood of 40.”

Some of the known signals mentioned include:

1. rel=”canonical” tags
2. 301 redirects
3. HTTPS vs. HTTP
4. Sitemaps
5. Internal linking
6. URL length

The weight and importance of each signal may vary, and some signals, like rel=”canonical” tags, can influence both the clustering and canonicalization process.

Balancing Signals

With so many signals at play, Allan acknowledged the challenges in determining the canonical URL when signals conflict.

He stated:

“If your signals conflict with each other, what’s going to happen is the system will start falling back on lesser signals.”

This means that while strong signals like rel=”canonical” tags and 301 redirects are crucial, other factors can come into play when these signals are unclear or contradictory.

As a result, Google’s canonicalization process involves a delicate balancing act to determine the most appropriate canonical URL.

Best Practices For Canonicalization

Clear signals help Google identify the preferred canonical URL.

Best practices include:

1. Use rel=”canonical” tags correctly.
2. Implement 301 redirects for permanently moved content.
3. Ensure HTTPS versions of pages are accessible and linked.
4. Submit sitemaps with preferred canonical URLs.
5. Keep internal linking consistent.

These signals help Google find the correct canonical URLs, improving your site’s crawling, indexing, and search visibility.

Mistakes To Avoid

Here are a few common mistakes to watch out for.

1. Incorrect or conflicting canonical tags:

• Pointing to non-existent or 404 pages
• Multiple canonical tags with different URLs on one page
• Pointing to a different domain entirely

Fix: Double-check canonical tags, use only one per page, and use absolute URLs.

2. Canonical chains or loops

When Page A points to Page B as canonical, but Page B points back to A or another page, creating a loop.

Fix: Ensure canonical URLs always point to the final, preferred version of the page.

3. Using noindex and canonical tags together

Sending mixed signals to search engines. Noindex means don’t index the page at all, making canonicals irrelevant.

Fix: Use canonical tags for consolidation and noindex for exclusion.

4. Canonicalizing to redirect or noindex pages

Pointing canonicals to redirected or noindex pages confuses search engines.

Fix: Canonical URLs should be 200 status and indexable.

5. Ignoring case sensitivity

Inconsistent URL casing can cause duplicate content issues.

Fix: Keep URL and canonical tag casing consistent.

6. Overlooking pagination and parameters

Paginated content and parameter-heavy URLs can cause duplication if mishandled.

Fix: Use canonical tags pointing to the first page or “View All” for pagination, and keep parameters consistent.

Key Takeaways

It’s unlikely the complete list of 40+ signals used to determine canonical URLs will be made publicly available.

However, this was still an insightful discussion worth highlighting.

Here are the key takeaways:

• Google uses approximately 40 different signals to determine canonical URLs, with rel=”canonical” tags and 301 redirects being among the strongest indicators
• When signals conflict, Google falls back on secondary signals to make its determination
• Clear, consistent implementation of canonicalization signals (tags, redirects, sitemaps, internal linking) is crucial
• Common mistakes like canonical chains, mixed signals, or incorrect implementations can confuse search engines

Hear the full discussion in the video below:

Featured Image: chatiyanon/Shutterstock

Google Warns Of Duplicate Content “Black Holes” Caused By Error Pages via @sejournal, @MattGSouthern

Google’s “Search Off the Record” podcast recently highlighted an SEO issue that can make web pages disappear from search results.

In the latest episode, Google Search team member Allan Scott discussed “marauding black holes” formed by grouping similar-looking error pages.

Google’s system can accidentally cluster error pages that look alike, causing regular pages to get included in these groups.

This means Google may not crawl these pages again, which can lead to them being de-indexed, even after fixing the errors.

The podcast explained how this happens, its effects on search traffic, and how website owners can keep their pages from getting lost.

How Google Handles Duplicate Content

To understand content black holes, you must first know how Google handles duplicate content.

Scott explains this happens in two steps:

1. Clustering: Google groups pages that have the same or very similar content.
2. Canonicalization: Google then chooses the best URL from each group.

After clustering, Google stops re-crawling these pages. This saves resources and avoids unnecessary indexing of duplicate content.

How Error Pages Create Black Holes

The black hole problem happens when error pages group together because they have similar content, such as generic “Page Not Found” messages. Regular pages with occasional errors or temporary outages can get stuck in these error clusters.

The duplication system prevents the re-crawling of pages within a cluster. This makes it hard for mistakenly grouped pages to escape the “black hole,” even after fixing the initial errors. As a result, these pages can get de-indexed, leading to a loss of organic search traffic.

Scott explained:

“Only the things that are very towards the top of the cluster are likely to get back out. Where this really worries me is sites with transient errors… If those fail to fetch, they might break your render, in which case we’ll look at your page, and we’ll think it’s broken.”

How To Avoid Black Holes

To avoid problems with duplicate content black holes, Scott shared the following advice:

1. Use the Right HTTP Status Codes: For error pages, use proper status codes (like 404, 403, and 503) instead of a 200 OK status. Only pages marked as 200 OK may be grouped together.
2. Create Unique Content for Custom Error Pages: If you have custom error pages that use a 200 OK status (common in single-page apps), make sure these pages contain specific content to prevent grouping. For example, include the error code and name in the text.
3. Caution with Noindex Tags: Do not use noindex tags on error pages unless you want them permanently removed from search results. This tag strongly indicates that you want the pages removed, more so than using error status codes.

Following these tips can help ensure regular pages aren’t accidentally mixed with error pages, keeping them in Google’s index.

Regularly checking your site’s crawl coverage and indexation can help catch duplication issues early.

In Summary

Google’s “Search Off the Record” podcast highlighted a potential SEO issue where error pages can be seen as duplicate content. This can cause regular pages to be grouped with errors and removed from Google’s index, even if the errors are fixed.

To prevent duplicate content issues, website owners should:

1. Use the correct HTTP status codes for error pages.
2. Ensure custom error pages have unique content.
3. Monitor their site’s crawl coverage and indexation.

Following technical SEO best practices is essential for maintaining strong search performance, as emphasized by Google’s Search team.

Hear the full discussion in the video below:

Featured Image: Nazarii_Neshcherenskyi/Shutterstock