Google’s Web.dev tool provides an SEO score ranging from 0 to 100. What exactly does this score measure in terms of SEO, and how useful is it?
What is SEO?
What should an SEO score indicate? That largely depends on your interpretation of SEO.
Moz defines SEO in terms of traffic:
"What is SEO?
Search engine optimization (SEO) is the practice of increasing the quantity and quality of traffic to your website through organic search engine results."
Wikipedia, however, defines SEO in the context of visibility in search rankings, using "visibility" as a stand-in for search engine ranking:
"Search engine optimization (SEO) is the process of affecting the online visibility of a website or a web page in a web search engine’s unpaid results—often referred to as ‘natural’, ‘organic’, or ‘earned’ results."
Search Engine Journal describes SEO as:
"The process of optimizing a website… so it will appear in prominent positions in the organic results of search engines. Successful SEO makes a site appealing to users and search engines."
- Moz emphasizes traffic in its definition.
- Wikipedia focuses on search engine rankings.
- Search Engine Journal highlights both ranking and user appeal.
The definition from Search Engine Journal is noteworthy because it underscores the importance of appealing to users. Google’s search algorithms aim to rank what users want to see. Failure to satisfy user preferences often leads to disappointment.
How Does Google Define SEO?
Google’s SEO Starter Guide describes SEO as:
"Search Engine Optimization is about helping search engines understand and present content."
This means writing content in a clear and focused manner, possibly enhancing it with images, structured data, and metadata to assist search engines in understanding a page’s purpose.
Google’s Web.dev platform explains SEO in terms of site crawlability and content comprehension, ultimately to attract more traffic:
"Making your content discoverable matters because it’s how you get more relevant users viewing your content…
By making sure search engines can find and automatically understand your content, you are improving the visibility of your site for relevant searches.
This is called SEO, or search engine optimization, which can result in more interested users coming to your site. Audit your site and check the SEO results to see how well search engines can surface your content."
What Does the Web.dev SEO Score Measure?
Web.dev builds upon Google’s Chrome Lighthouse extension. According to the official Lighthouse page, these are the nine factors Google evaluates for the SEO score:
- Missing meta description
- Absent title element
- Invalid hreflang
- Invalid rel=canonical
- Illegible font sizes
- Use of plugins (Flash)
- Links lack descriptive text
- Unsuccessful HTTP status code on page
- Page blocked from indexing
What Does the Web.dev SEO Score Mean?
According to Web.dev, Google’s SEO score gauges how well search engines can “surface” content.
What does "surface" mean here? Does it imply the ability to rank content, or the capacity to discover it? It seems Google is indicating how successfully it can crawl and find content.
The definition given on the main Web.dev page reads:
"Checks for best practices to ensure your site is discoverable."
Discoverability is further described as:
"Easily discoverable
Ensure users can find your site easily through search."
This is a purposefully ambiguous explanation of discoverability. Is Google talking about ranking or about making content easier to find, assuming other ranking factors align?
Google remains vague on what SEO precisely entails.
Publishing experts view SEO regarding ranking and traffic. Yet, Google’s Web.dev pages avoid using the word "rank" in discussions about its SEO metric.
Google avoids mentioning rank or ranking on their Web.dev platform, likely purposefully.
The Web.dev site addresses SEO in terms of crawling and content comprehensibility, not ranking.
No results appear when searching for the terms rank and ranking.
The emphasis is on making content easy to find, not on improving rank.
Page Scores 90 and Ranks #85
Here is an example of a web page ranked #85 for the search term "how to diagnose arthritis."
The page’s Web.dev SEO score is 90. It didn’t reach 100 because it lacks a meta description tag.
Given that a meta description isn’t crucial for ranking, contributing to 10% of the SEO score is significant. This highlights that the SEO score emphasizes discoverability—crawling and indexing—rather than ranking and traffic.
Is Web.dev’s SEO Score a Useful Metric?
The score’s usefulness depends on your definition of SEO. Google’s interpretation involves checking for title tags, meta descriptions, and access to the page—elements considered rudimentary SEO.
Typically, the SEO industry and sources like Wikipedia start with Google’s basics and expand to include traffic, ranking, and user satisfaction.
Expecting Google to offer an SEO tool indicating the ranking potential of a page is unrealistic. This is among the reasons Google discontinued its PageRank toolbar meter.
Google’s Web.dev SEO score diverges from the broader industry definition of SEO.
The SEO score doesn’t predict ranking potential, as demonstrated by pages scoring high yet ranking low.
SEO’s broader industry associations with rankings and traffic are not addressed by Web.dev.
For accuracy, Web.dev’s SEO score might be better labeled an Indexability or Discoverability Score.
