SEO for HTML: the tags that matter and the ones that do not

What each element does for search

A skeleton you can copy

Here is the order of a clean page head and body, described in words so you can map it to your template.

1. Document languageSet the lang attribute on the html element to the page language, for example en-US or en-GB. It helps screen readers and language detection.
2. Head essentialsCharacter set, viewport, a unique title, a meta description, and the canonical link. Add open graph tags if you want good link previews on social platforms.
3. Structured dataA JSON-LD script in the head or body describing the organization, article, product or local business that the page is actually about.
4. LandmarksUse header, nav, main, article, aside and footer instead of a pile of generic div elements. They give crawlers and assistive technology a map.
5. One h1 inside mainThen h2 sections in order, with h3 under them. Do not skip levels for styling. Use CSS for size.
6. Links and images with meaningDescriptive anchor text and alt text, width and height attributes on images to prevent layout shift.

Where HTML and JavaScript collide

Google can run JavaScript, but it does so in a second step that can take longer. If your important text, links or product details only appear after scripts run, indexing can be delayed or incomplete. Check this directly: open the page source (not the inspector), search for a sentence from the main content, and if it is missing from the source, the server is not sending it.

• Prefer server-side rendering or static generation for pages you want ranked. Frameworks such as Next.js support both. See our guide on Next.js SEO.
• Navigation links should be anchor tags with an href. Click handlers on buttons or divs do not give crawlers a URL to follow.
• Do not hide the main content behind a tab that loads only on click if you want it to rank.
• Use the URL Inspection tool in Search Console to see the rendered HTML that Google actually stored.

Old advice to drop

A quick test list

• View source and confirm the title, description, canonical and h1 are present without running scripts.
• Run the page through an HTML validator and fix unclosed elements, which can swallow content.
• Use Google's Rich Results Test or the Schema Markup Validator on pages with structured data.
• Check the mobile rendering in URL Inspection.
• Search your site for pages with duplicate titles and empty h1 elements.

A crawl of the whole site catches these in minutes. Our technical SEO work starts there, and the technical SEO checklist and schema markup checklist list every item. Ask for a fixed quote after a short call on the contact page.

Pitfalls

• Templates that copy the same title onto hundreds of pages.
• A noindex tag copied from staging to production.
• Canonical tags pointing to a redirected or blocked URL.
• Using headings for style, such as an h4 above an h2, which breaks the outline.
• Alt text stuffed with keywords. Describe the image as you would to a person who cannot see it.