Search Engine Optimization (SEO)

A helpful checklist / collection of Search Engine Optimization (SEO) tips and techniques.

Contents

• URL
• Accessibility
• Meta Information
• Keywords
• Content
• Images
• Videos
• Links
• Mobile
• Sitemap
• Social Media
• Tools & Services
• Webmasters
• Analytics
• Optimization
• Keywords
• Links
• Structured Data
• Bookmarklets
• Browser Extensions
• Jekyll Plugins
• TYPO3 Extensions
• WordPress Plugins
• Books
• Courses

URL

• Descriptive URLs: Use a descriptive page url, which should reflect your targeted keyword.
• File extension - Do not strip out the file extension on URLs.
• HTTPS - Security is a top priority for Google.
• Hyphens - Split words using hyphens.
• Localisation - Choose a country-specific domain, for better local search results.
• Subdomain or subfolder - Subdomains are seen as separate domains.
• URL builder - Use this tool to add custom campaign parameters to your URLs.

Accessibility

• 403: Provide a 403 - Access denied page.
• 404: Provide a 404 - Page not found page.
• Custom Search - With Google Sitelink search box, people can reach your content more quickly.
• File not found: Avoid 404 FILE_NOT_FOUND errors.
• Layout: Use divs instead of tables for layout. Using tables is not semantically correct.
• Moving a website: Redirect all your links to the new location via .htaccess.
• Pagination - Implement the rel="next" and rel="prev" attributes to links.
• Performance - Performance and loading time is important.
• Redirects: Avoid redirects if possible. Use 301 redirect instead of 302.
• RichSnippets - Markup your code with rich snippets, they show up on the search results page.
• Robots - Block pages which should not be indexed via the robots.txt file or <meta name="robots" content="">.
• Validation: Write valid code (HTML Validator CSS Validator).
• WAI-Aria - Use WAI-Aria tags to help machines understand your code.

Meta Information

• Description - Each page should have a unique description (max. 160 characters) <meta name="description" content="">.
• Title: Each page should have a unique speaking title (60 - 100 characters) <title>Website Title</title>.

Keywords

• Content: Keyword should appear in ~3% of article length.
• Heading: Keyword should appear in headings.
• Meta Tag - You can ommit the <meta name="keywords" content="">, search engines do not use this meta tag.
• Research: Rank for keywords with high traffic and less competition.
• Single: Every page should have a single unique targeted keyword.
• Title: Keyword should appear in page title.
• URL - Keyword should appear in URL name.

Content

• Content: Content matters the most in SEO.
• Flash: Avoid Flash content and Flash pages. They are not accessible on mobile phones and will be ranked lower.
• Freshness: New content is important. Updating pages or posting regularly is recommended.
• Headings: Clear structure H1 -H6 max. 70 characters long.
• Length: Article should be at least 300 words.
• Strong: Use strong tag to highlight your targeted keyword.
• Uniqueness - Do not provide duplicated content, use unique content types.

Images

• Alt tag - Add an alt-tag this a description of the image (60 - 70 characters).
• Dimensions: Add the width="" and height="" attributes to the image.
• File name - Use a short descriptive name.
• Optimization - Optimize images by removing some meta information.
• Responsive Images - Serve the most optimized image corresponding to the window size.
• Size: keep the filesize as low as possible.