Use Lighthouse to check your website's SEO. You will see the same exact information in the SEO report.
SEO (Search Engine Optimization) is the process of making a website more visible in search results, also termed improving search rankings.
Search engines crawl the web, following links from page to page, and index the content found. When you search, the search engine displays the indexed content. Crawlers follow rules. If you follow those rules closely when doing SEO for a website, you give the site the best chances of showing up among the first results, increasing traffic and possibly revenue (for ecommerce and ads).
To learn more, check this page, where I copy-pasted the content above.
Page speed is a measurement of how fast the content on your page loads. Here are some reasons why page speed matters:
If your site takes a long time to load, users will be frustrated which will result in a lower ranking in search results.
Google can crawl your unoptimized page, but the page may not be indexed or be visible in search results. (see crawl budget)
To learn more, here's a link to the Performance cheat sheet.
- Structured data is valid
- Has a
<meta name="viewport">tag with width or initial-scale
<meta name="viewport"> not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input.
- Document has a
The title gives screen reader users an overview of the page, and search engine users rely on it heavily to determine if a page is relevant to their search
- Document has a meta description
Meta descriptions may be included in search results to concisely summarize page content.
- Page has successful HTTP status code
Pages with unsuccessful HTTP status codes may not be indexed properly.
- Links have descriptive text
Descriptive link text helps search engines understand your content.
- Links are crawlable
Search engines may use
href attributes on links to crawl websites. Ensure that the
href attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered.
- Page isn’t blocked from indexing
Search engines are unable to include your pages in search results if they don't have permission to crawl them.
If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed.
- Image elements have
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute.
- Document has a valid
hreflang links tell search engines what version of a page they should list in search results for a given language or region.
- Document has a valid
Canonical links suggest which URL to show in search results.
- Document avoids plugins
Search engines can't index plugin content, and many devices restrict plugins or don't support them.
- Document uses legible font sizes
Font sizes less than 12px are too small to be legible and require mobile visitors to “pinch to zoom” in order to read. Strive to have >60% of page text ≥12px.
- Tap targets are sized appropriately
Interactive elements like buttons and links should be large enough (48x48px), and have enough space around them, to be easy enough to tap without overlapping onto other elements.
Additional note: The list above may not be that exhaustive as this article focused on Lighthouse's recommendations. There are other things to consider to improve SEO which I will try to compile in another article.