SEO score vs Performance score.

[vimal-here]

Summary

My website has got a good SEO score for mobile

But the performance score is very bad.

Question: As the SEO score is good, can I assume that my website's search engine ranking will be good, regardless of the bad performance score?

The SEO report says

These checks ensure that your page is optimized for search engine results ranking

[patrickhulce]

As the SEO score is good, can I assume that my website's search engine ranking will be good, regardless of the bad performance score?

No, this is not a safe assumption. The SEO category score represents how many common SEO mistakes were avoided and is not a comprehensive assessment.

Your misunderstanding raises a valid point though!

Lighthouse team, WDYT about a CWV-style audit that has a high SEO weight and represents whether LCP/CLS/TBT are passing? Wording would need to be carefully chosen to avoid confusion with actual CWV metric thresholds, but something to capture the spirit of CWV in SEO would be nice instead of easily getting 100s.

[connorjclark]

Main concern with that: assigning any weight to a performance part of the SEO score is going to be mistakenly seen as authoritative, coming from us. We have no idea what the weighting really is in Search.

[patrickhulce]

This concern sounds like an argument against us having an SEO category score at all :) (which, to be fair, could be a possible outcome here)

If we are going to have an SEO category though, one that is almost always ~90+ and is missing major components of the score that we know to be considered seems rather misleading. IMO, we either try to capture the aspects of SEO we know about and can automatically check, or we punt it to plugin land.

[evolve2k]

Drawing on peoples concerns above, that it would be a real shame to loose the SEO score as it provides an important baseline to ensure that essentials are covered.

In light of the above I'm suggesting the 'SEO' section be renamed 'SEO Essentials'.
And the copy beneath just making clear that this is not everything but common details to get right.

Lighthouse improves overall website quality across the web and I suggest it keeps that focus.

[benschwarz]

This concern sounds like an argument against us having an SEO category score at all :) (which, to be fair, could be a possible outcome here)

I believe removing the SEO category score (actually, all category scores 🤪) would be a positive improvement. The technical SEO audits are helpful, but are in no way an exhaustive list that ensure a high listing. Having a score muddies that information.

[patrickhulce]

We're going to be updating the category description to indicate more strongly that there are many aspects of SEO that are not captured in the SEO category, including performance.

[vimal-here]

@patrickhulce Thanks for the update.
Now understood that - If the SEO score is above 90, we cannot safely assume that the search engine rankings will also be good if the LH performance score is bad.

Do we have a calculation already or a weight-age in terms of search engine ranking for both LH's performance & SEO scores?
For example, if the performance score is above 90 and SEO score is below 10, what will be the level of impact in terms of search engine ranking? Will it be more critical than the use case I shared in my first comment?

[patrickhulce]

For example, if the performance score is above 90 and SEO score is below 10, what will be the level of impact in terms of search engine ranking?

No mapping of Lighthouse score to search ranking impact exists. Lighthouse is a tool to help debug and monitor signals for improvements, not the canonical explanation of all search ranking issues.

To that point, I'm not aware of any tool or document that explains the exact impact of all search ranking issues (nor do I think it would be a good idea for one to exist due to exploitation), but you should be able to take a look at Search Console and the field data section of PageSpeed Insights for search's explanations.

[vimal-here]

@patrickhulce - Sure, thanks for the inputs.