How to improve your SEO score: find out which tool gave it, then fix what that tool counts

To improve your SEO score, first find out which tool produced it, because every score counts something different. Then fix the failed checks that carry the most weight, starting with anything that stops the page being indexed, and run the same tool again. In Lighthouse, one check, whether the page can be indexed, is worth about four times any other, and failing it alone drops the score to 69. A site health score from a crawler rises as you clear errors across the site, and a plugin score rises post by post. Google does not read any of these numbers, so treat a higher score as proof the basics are fixed and judge the result in Search Console.

Which SEO score are you looking at?

"SEO score" is not one measurement. Four kinds of tool give one, and the way to raise each is different.

Kind of score	What it scores	Where you see it
Lighthouse SEO category	One page, 0 to 100, from ten weighted checks	Chrome DevTools, PageSpeed Insights, the command line
Crawler site health score	The whole site, from the issues a crawl finds	Site audit tools such as Semrush and Ahrefs
Plugin score	One post or page, against the plugin's content checks	Yoast SEO, Rank Math and similar WordPress plugins
Online checker score	One live URL, from a short list of on page checks	Free web checkers, such as Yoast's SEO Checker

If your number came from an agency report or a sales email, ask which tool made it. A score you cannot reproduce is a score you cannot improve.

Raising a Lighthouse SEO score

Lighthouse is an open source auditing tool from the Chrome team. You can run it in Chrome DevTools, from the command line or as a Node module, and its SEO category is also shown in PageSpeed Insights. We read the weights directly from the Lighthouse source code on GitHub on 22 October 2026.

There are ten automatic checks. Nine carry a weight of 1. The check called is-crawlable, which asks whether search engines are allowed to index the page, carries a weight of 93/23, about 4. A comment in the code explains why: it should be at least 31% of the score, "such that this audit failing results in the SEO category failing." So the arithmetic is simple:

• Fail only the indexing check and the score is about 69.
• Fail any one of the other nine and it is about 92.
• Each further ordinary failure takes off roughly another 8 points.

That gives you the order of work. Fix indexing first, then everything else in any order. Here is what each check wants:

• Page isn't blocked from indexing. Remove a noindex robots meta tag or an X-Robots-Tag: noindex header from any page you want found, including tags aimed at one crawler such as Googlebot. Lighthouse's own documentation gives legal pages as an example of content that can stay out.
• Document has a title element. One unique title per page.
• Document has a meta description. A short, specific summary of the page.
• Page has successful HTTP status code. The page returns 200, not an error.
• Links have descriptive text. Replace "click here" and "read more" with words that say where the link goes.
• Links are crawlable. Use real a elements with an href, not script-only click handlers.
• robots.txt is valid. Fix syntax errors in the file.
• Image elements have alt attributes. Describe each meaningful image.
• Document has a valid hreflang. Only relevant if you publish language or country versions.
• Document has a valid rel=canonical. One canonical, pointing at a real, indexable URL.

An eleventh item, structured data, is a manual check with a weight of zero, so it never changes the number. Test your markup separately. For the detail on each check and the failures that trip people up, see our guide to the ten checks behind the Lighthouse SEO score.

Raising a site health score from a crawler

Yoast's guide to performing an SEO audit describes the site audit in tools such as Semrush and Ahrefs as giving you "a technical health score from which to work". Each vendor counts issues its own way, which is why two tools give the same site different numbers. What raises all of them is the same: fewer errors found on the pages the crawler visits.

1. Fix by template, not by page. A missing meta description on 400 product pages is usually one field in one template. Fix the template and hundreds of issues close at once.
2. Clear errors before warnings and notices. Broken pages, broken internal links and redirect chains come first.
3. Start with the pages that earn traffic. Sort by clicks in Search Console and work down, so each fix helps real visitors.
4. Remove pages that should not exist, with a redirect where they had links or visitors.
5. Re-crawl with the same settings. Change the crawl scope and the score changes for reasons that have nothing to do with your site.

Keep the scope honest. Leaving problem sections out of the crawl moves the number and fixes nothing.

Raising a plugin score on a post

WordPress plugins score each post against their own content checks. Yoast's Dashboard groups posts as good, OK or needing improvement, for SEO and for readability, and lets you filter by content type and category. Two habits make these scores rise without harming the writing:

• Work the checks that matter to a reader first: a clear title, a meta description, the focus phrase used where a reader would expect it, internal links and alt text.
• Update the post after you change it. Yoast's help centre notes that a post's SEO score is only recalculated when the post is updated, which also explains a score that moved after a plugin update with no edit to the text.

If you use Rank Math, its analyzer works differently and splits its tests into sections. Our walkthrough of the Rank Math SEO Analyzer and the order to fix its tests covers that one.

What moves rankings once the score is high

A high score is the floor. Lighthouse says so in its own description of the SEO category: "There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals." Google's page experience documentation (last updated 22 September 2026) confirms that Core Web Vitals are used by its ranking systems, and adds that "trying to get a perfect score just for SEO reasons may not be the best use of your time."

So once the score is green, put the hours into what the score does not count: pages that answer the searches your buyers make, links from sites they trust, and pages that load quickly on a phone. Search Console's Performance report is where that work shows up, as impressions and clicks.

Questions about improving an SEO score

What is a good SEO score?

For Lighthouse, aim for 90 or more, which means at most one minor check is failing. For a crawler's health score, compare against your own last crawl rather than another site. For a plugin, aim for a good rating on the pages that earn traffic.

Does a score of 100 help my Google ranking?

It shows Google can index and read the page, which is required to rank at all. Ranking itself is decided by relevance, quality and the other factors Lighthouse says it does not score.

Why did my score drop when I changed nothing?

Usually the tool changed or the crawl did. A crawler may have found new pages, a plugin may have recalibrated its checks, or a theme update may have removed a tag. Re-run with the same settings and compare the list of failed checks, not the number.

Why do two tools give my site different scores?

They run different checks with different weights over different sets of pages. Pick one tool for tracking and use the others for a second opinion on specific issues.

How quickly can I see a higher score?

Lighthouse and online checkers update the moment you re-run them. A crawler updates on its next crawl. Rankings respond on Google's schedule, so watch Search Console over the following weeks.

The score Lighthouse is starting to add

The same Lighthouse source code that weights the SEO checks now carries a new category, Agentic Browsing, which it describes as checks for "browsable websites for AI agents" and labels as still under development. That is a sign of where scoring is going: from whether a search engine can read a page to whether an AI system can use it. Being readable is step one. Whether ChatGPT, Gemini or Perplexity actually name your business when a buyer asks is a separate result, and it does not appear in any SEO score. AI Knows Us measures that result across the main assistants and works out why a business is left out.