# Search Engine Optimization (SEO) [![Awesome](https://awesome.re/badge.svg)](https://awesome.re) A helpful checklist / collection of Search Engine Optimization (SEO) tips and techniques. ## Contents - [URL](#url) - [Accessibility](#accessibility) - [Meta Information](#meta-information) - [Keywords](#keywords) - [Content](#content) - [Images](#images) - [Videos](#videos) - [Links](#links) - [Mobile](#mobile) - [Sitemap](#sitemap) - [Social Media](#social-media) - [Tools & Services](#tools--services) - [Webmasters](#webmasters) - [Analytics](#analytics) - [Optimization](#optimization) - [Keywords](#keywords-1) - [Links](#links-1) - [Structured Data](#structured-data) - [Bookmarklets](#bookmarklets) - [Browser Extensions](#browser-extensions) - [Jekyll Plugins](#jekyll-plugins) - [TYPO3 Extensions](#typo3-extensions) - [WordPress Plugins](#wordpress-plugins) - [Books](#books) - [Courses](#courses) ## URL - Descriptive URLs: Use a descriptive page url, which should reflect your targeted keyword. - [File extension](https://www.youtube.com/watch?v=dSG6C33GwsE) - Do not strip out the file extension on URLs. - [HTTPS](https://webmasters.googleblog.com/2014/08/https-as-ranking-signal.html) - Security is a top priority for Google. - [Hyphens](https://www.youtube.com/watch?v=AQcSFsQyct8) - Split words using hyphens. - [Localisation](https://support.google.com/webmasters/answer/62399) - Choose a country-specific domain, for better local search results. - [Subdomain or subfolder](https://www.youtube.com/watch?v=_MswMYk05tk) - Subdomains are seen as separate domains. - [URL builder](https://support.google.com/analytics/answer/1033867) - 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](https://developers.google.com/structured-data/slsb-overview) - 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](https://support.google.com/webmasters/answer/1663744) - Implement the `rel="next"` and `rel="prev"` attributes to links. - [Performance](https://developers.google.com/webmasters/mobile-sites/mobile-seo/common-mistakes/slow-mobile-pages) - Performance and loading time is important. - Redirects: Avoid redirects if possible. Use 301 redirect instead of 302. - [RichSnippets](https://schema.org/) - Markup your code with rich snippets, they show up on the search results page. - [Robots](https://en.wikipedia.org/wiki/Robots_exclusion_standard) - Block pages which should not be indexed via the `robots.txt` file or ``. - Validation: Write valid code ([HTML Validator](https://validator.w3.org/) [CSS Validator](https://jigsaw.w3.org/css-validator/)). - [WAI-Aria](https://www.w3.org/TR/wai-aria/) - Use WAI-Aria tags to help machines understand your code. ## Meta Information - [Description](https://www.youtube.com/watch?v=W4gr88oHb-k) - Each page should have a unique description (max. 160 characters) ``. - Title: Each page should have a unique speaking title (60 - 100 characters) `Website Title`. ## Keywords - Content: Keyword should appear in ~3% of article length. - Heading: Keyword should appear in headings. - [Meta Tag](https://www.youtube.com/watch?v=jK7IPbnmvVU) - You can ommit the ``, 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](https://www.youtube.com/watch?v=rAWFv43qubI) - 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](https://www.youtube.com/watch?v=mQZY7EmjbMA) - Do not provide duplicated content, use unique content types. ## Images - [Alt tag](https://support.google.com/webmasters/answer/114016) - 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](https://www.youtube.com/watch?v=h2SWuUobbr0) - Use a short descriptive name. - [Optimization](https://imageoptim.com/) - Optimize images by removing some meta information. - [Responsive Images](https://www.w3.org/TR/html-picture-element/) - Serve the most optimized image corresponding to the window size. - Size: keep the filesize as low as possible. ## Videos - Controls: Add controls to playback and control your video. - Embed: Allow others to embed your videos. - Transcriptions: Use transcriptions for indexing, usability & content. - [Unplayable content](https://developers.google.com/webmasters/mobile-sites/mobile-seo/common-mistakes/unplayable-content) - Avoid unplayable video content. Use HTML5 `