What this SEO check looks at
The check sends your URL to Google PageSpeed Insights, which loads the page the way a phone or a desktop computer would and runs Lighthouse, Google's open-source auditing tool. It takes about 10 to 30 seconds, because the page is really being loaded and measured.
You get back four category scores and a list of individual checks:
- SEO: basic things search engines need, such as a page title, a meta description, a page that is allowed to be indexed, crawlable links and image alt texts.
- Performance: how fast the page shows content and becomes usable, measured in a simulated, throttled environment.
- Accessibility: whether people using screen readers, keyboards or zoom can use the page. Many fixes here also help search engines understand your content.
- Best Practices: HTTPS, browser errors, outdated code and other signs of a healthy website.
On top of that you see Core Web Vitals. If enough Chrome users have visited your page, these come from real-user data in the Chrome UX Report. If not, you see lab values from the test run instead.
The check covers exactly one URL. Your home page, your contact page and your product pages can score very differently, so test the pages that matter most to your business.
How to read your scores
Each Lighthouse category is scored from 0 to 100. Google uses the same color bands everywhere:
| Score | Color | What it means |
|---|---|---|
| 90–100 | Green | Good. Fix any remaining items if they are easy. |
| 50–89 | Orange | Needs improvement. Look at the failed checks first. |
| 0–49 | Red | Poor. Something important is likely broken or very slow. |
The overall score at the top summarizes the four categories so you can compare runs at a glance. The category scores and the failed checks underneath are more useful for deciding what to do.
Why a 100 SEO score doesn't mean you rank #1
The SEO score only checks technical basics: can Google read and index the page, and are the key tags present? It says nothing about whether your content answers what people search for, how many other sites link to you, or how strong your competitors are. Think of it as a checklist that removes obstacles, not as a ranking prediction. A bakery with an SEO score of 85 and great local reviews can easily outrank one with a perfect 100.
Performance scores also vary between runs by a few points, depending on server load and network conditions. Don't chase small changes. Run the test two or three times if a result looks odd.
Core Web Vitals and their thresholds
Core Web Vitals are three metrics Google uses to describe how a page feels to real visitors. They are part of Google's page experience signals, but good content still matters far more.
| Metric | What it measures | Good | Poor |
|---|---|---|---|
| LCP (Largest Contentful Paint) | How long until the main content, often a large image or heading, is visible | ≤ 2.5 s | > 4 s |
| INP (Interaction to Next Paint) | How quickly the page reacts when someone taps or clicks | ≤ 200 ms | > 500 ms |
| CLS (Cumulative Layout Shift) | How much the layout jumps around while loading | ≤ 0.1 | > 0.25 |
Values between good and poor count as “needs improvement.” For field data, Google looks at the 75th percentile, so most of your visitors need a good experience, not just the ones on fast Wi-Fi.
INP only exists in field data, because it needs real people interacting with the page. In lab results you will see TBT (Total Blocking Time) instead, which estimates how long scripts block the page from responding, and FCP (First Contentful Paint), the moment the first text or image appears. Google's own explanation is on web.dev.
Small business sites often have no field data because they don't get enough Chrome traffic. That's normal. Use the lab values as a guide instead.
The most common problems and how to fix them
Missing title or meta description
Every page needs its own <title> and meta description. Most website builders (WordPress, Wix, Squarespace, Shopify) have an SEO field for this in the page settings. Write a title that says what the page is about and where, for example “Emergency Plumber in Denver | Smith Plumbing.” You can test the length with the SERP preview.
Page is set to noindex
A noindex tag tells Google not to show the page in search results. It is often left over from building the site, or set by a “discourage search engines” checkbox. Remove it in your SEO plugin or site settings, unless you really want the page hidden.
Blocked by robots.txt
Your robots.txt file can stop Google from crawling pages. A single line like Disallow: / blocks the whole site. Test your file with the robots.txt tester.
Images without alt text
Alt text describes an image for screen readers and search engines. Write what is actually shown: “Fresh sourdough loaves on a wooden counter” beats “image1” or a list of keywords. Purely decorative images can have an empty alt attribute.
Links without descriptive text
Links that just say “click here” or “more” don't tell anyone where they lead. Use the destination as the link text, such as “See our haircut prices.”
Slow, oversized images
Photos straight from a phone or camera are often several megabytes. Resize them to the size they are displayed at, save them as WebP or a compressed JPEG, and use lazy loading for images further down the page. This is the most common reason for a poor LCP.
Render-blocking CSS and JavaScript
Stylesheets and scripts in the page head can delay everything else. Remove plugins and widgets you don't use, load scripts with defer where possible, and turn on the optimization settings of your caching plugin or website builder.
No HTTPS
Browsers mark pages without HTTPS as “not secure.” Most hosts offer a free certificate. Turn it on and redirect all http:// addresses to https://.
Missing viewport tag
Without a viewport meta tag, phones show a shrunken desktop version of your page. Modern themes include it. If yours doesn't, add this to the page head:
<meta name="viewport" content="width=device-width, initial-scale=1">Mobile or desktop: which result matters?
Google mainly uses the mobile version of your site for indexing and ranking, so start with the mobile result. The mobile test simulates a mid-range phone on a slower connection, which is why its performance score is usually lower than desktop. That's expected. If most of your customers find you on their phones, as is typical for hair salons, cafés and tradespeople, the mobile numbers are the ones to improve.
What a single-page check can't tell you
Lighthouse looks at one page at a time. Some important problems only show up when you look at the whole site or at Google's own data:
- Broken links pointing to pages that no longer exist
- Duplicate titles and descriptions across many pages
- Sitemap problems, such as missing pages or old URLs
- Indexing status: whether Google has actually indexed the page
- Search performance: which searches you appear for, clicks and positions
For indexing and search data, use Google Search Console. It's free and comes straight from Google. If a page doesn't show up at all, this guide on why a page is not indexed walks through the usual causes. To check many pages at once, the RankTutor iPhone app checks up to 100 pages of a site.
After the check: a simple plan
- Fix anything that stops indexing first: noindex, robots.txt blocks, error status codes.
- Give each important page a unique title and meta description.
- Compress and resize large images, then run the check again to see the effect on LCP.
- Work through the remaining failed checks, starting with the ones that are quick to fix.
- Add structured data for your business, for example with the structured data generator.
- Repeat the check for your other key pages: services, prices, contact, top products.
- Check again after website updates, new plugins or a theme change.
For a deeper walkthrough of a full website audit, read the website SEO check guide.