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Definitions, examples and related tools. Find an unfamiliar term from your audit or search by topic.
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Alt text (the alt attribute) is a text description of an image for search engines and screen readers. It affects image SEO and website accessibility.
Related tool: Image checkAnchor text is the visible, clickable text of a hyperlink. It affects SEO: search engines use it to determine the topic of the destination page. It matters for internal and external linking.
Related tool: Link analyzerBacklinks are incoming links from other websites. They are one of Google’s main ranking factors. Learn how to get quality backlinks.
Related tool: Link analyzerBreadcrumbs are a website navigation element that shows the path from the homepage to the current page. They improve UX, site structure, and SEO through Schema.org markup.
Related tool: Schema ValidatorBrotli is a modern compression algorithm from Google that replaces Gzip. It compresses HTML/CSS/JS 20-30% better. It is supported by all modern browsers.
Related tool: HTTP/2 & BrotliA canonical URL (rel=canonical) is an HTML attribute that tells search engines which version of a page is the primary one when duplicates exist. Learn how to configure canonical correctly.
Related tool: Canonical CheckerA CDN (Content Delivery Network) is a network of servers around the world that delivers content to users quickly. It reduces TTFB and speeds up the delivery of static files.
Related tool: HTTP/2 & BrotliCLS is a Core Web Vitals metric that measures a page’s visual stability. It accounts for unexpected content shifts during loading. Good: up to 0.1.
Related tool: Web VitalsMinification is the removal of unnecessary characters from CSS, JS, and HTML without changing functionality. It reduces file size by 20-60%.
Related tool: Code MinifierCookies are small data files stored by a browser. They are used for authentication, analytics, and personalization. GDPR requires consent for analytics cookies.
Related tool: Cookie analyzerCore Web Vitals are three Google metrics for evaluating user experience: LCP, INP, and CLS. They affect rankings and website performance.
Related tool: Web VitalsCORS (Cross-Origin Resource Sharing) is a browser mechanism for controlling requests between different domains. Incorrect CORS configuration is a security threat.
Related tool: Security HeadersCSP is an HTTP security header that prevents unauthorized scripts from running and resources from being loaded from other websites. It protects against XSS attacks.
Related tool: CSP AnalyzerDNS (Domain Name System) is a domain name system that translates website addresses into server IP addresses. Learn how DNS works and what types of records exist.
Related tool: DNS LookupDuplicate content is identical text on multiple URLs. It can cause SEO problems: search engines may not know which version to show and may split link equity.
Related tool: Canonical CheckerA favicon is a small website icon displayed in browser tabs, bookmarks, and history. It affects brand recognition and the professional appearance of a website.
Related tool: Favicon checkA Featured Snippet (position 0) is a highlighted answer block at the top of the SERP. It can drive significant traffic growth. Learn how to optimize content for featured snippets.
Related tool: FAQ Schema GeneratorFID is an obsolete Core Web Vitals metric that measured the delay before the first interaction. It was replaced by INP in March 2024. Find out why INP is more accurate.
Related tool: Web VitalsH1 is the main heading of a page and one of the key on-page SEO factors. Learn the rules for using H1 to improve search engine rankings.
Related tool: Meta tag checkHreflang is an HTML attribute used to specify a page's language and region. It helps search engines show the right version of a site to users in different countries.
Related tool: Hreflang CheckerHSTS (HTTP Strict Transport Security) is a security header that forces browsers to switch to HTTPS. It protects against traffic interception attacks.
Related tool: Security HeadersHTTP/2 is a second-generation data transfer protocol. It speeds up website loading through multiplexing, header compression, and Server Push.
Related tool: HTTP/2 & BrotliIndexability is the ability of pages on a website to be included in the Google and Yandex search indexes. Without indexing, a page will not appear in search results.
Related tool: robots.txt analyzerINP is a Core Web Vitals metric that measures page responsiveness to clicks and key presses. It replaced FID in March 2024. Good: up to 200 milliseconds.
Related tool: Web VitalsInternal links are links between pages on the same website. They distribute PageRank and help crawlers and users find important pages.
Related tool: Link analyzerLazy loading is an optimization technique in which images and content are loaded only when they enter the viewport.
Related tool: Image checkLCP is a Core Web Vitals metric that measures how long it takes for the largest visible element on a page to load. Target: up to 2.5 seconds. A direct Google ranking factor.
Related tool: Web VitalsA meta description is a brief summary of a page shown in search results. It does not directly affect rankings, but a well-written description can increase CTR.
Related tool: Meta tag checkMeta tags are HTML elements in the head section that provide information about a page to search engines and browsers. Find out which meta tags matter for SEO.
Related tool: Meta tag checkOn-page SEO is the optimization of individual website pages: headings, meta tags, content, and images. These direct ranking factors are under the webmaster’s control.
Related tool: Meta tag checkOpen Graph is a page markup protocol for attractive previews when links are shared on social media. Learn which og tags you need and how to set them up correctly.
Related tool: Open Graph PreviewPage Speed is the time it takes a web page to load. It directly affects SEO rankings, conversions, and user behavior metrics. Google takes speed into account when ranking pages.
Related tool: Full site checkPagination splits content across pages (/page/2, ?page=2). It is important to configure canonical tags and links correctly so paginated pages do not harm SEO.
Related tool: Broken linksPeople Also Ask is the “People also ask” section in Google. It displays related questions. Appearing in PAA brings additional traffic and increases authority.
Related tool: Content idea generatorPreload is a directive for loading resources before they are discovered by the parser. It speeds up LCP and the loading of fonts and critical scripts. It is used with link rel=preload.
Related tool: Full site checkResponsive design is a web development approach in which a website displays correctly on all devices: mobile phones, tablets, and desktops.
Related tool: Responsive TesterA Rich Snippet (enhanced snippet) is a search result with additional data, such as a rating, price, or breadcrumbs. It requires Schema.org markup on the page.
Related tool: Schema ValidatorMeta robots is an HTML tag for managing the indexing and crawling of a specific page. The noindex, nofollow, and nosnippet directives provide precise control over bot behavior.
Related tool: robots.txt analyzerRobots.txt is a text file in a website’s root directory that controls search engine crawlers’ access to pages. Learn how to configure robots.txt correctly for SEO.
Related tool: robots.txt analyzerSchema.org is a vocabulary of structured data for semantic markup of web pages. It is used with JSON-LD to obtain rich snippets in search results.
Related tool: Schema ValidatorAn SEO audit is a comprehensive website check to identify factors that hinder rankings. It includes technical analysis, on-page SEO, backlink profile, and content.
Related tool: Full site checkSERP (Search Engine Results Page) is a search results page. It contains organic results, ads, featured snippets, and rich results. Learn how to improve your snippet.
Related tool: SERP PreviewA sitemap is an XML file listing all the pages on a website for search engine crawlers. Learn how to create and check a sitemap.xml file.
Related tool: Sitemap checkSrcset is an HTML attribute for responsive images. It lets the browser choose the optimal image size for each device and screen density.
Related tool: Image checkAn SSL certificate is a digital document that encrypts the connection between a browser and a server. Without one, the browser displays “Not secure.”
Related tool: SSL CheckerStructured data describes page content using Schema.org. Types supported by search engines can enable rich results, such as price, ratings, and recipe information.
Related tool: Schema ValidatorTechnical SEO is the optimization of a website’s technical aspects: crawling, indexing, speed, security, and structured data. It is the foundation for all other SEO.
Related tool: Full site checkThe title tag is an HTML element that contains a page title and appears in the browser tab and search snippet. It is the most important on-page SEO factor.
Related tool: Meta tag checkTTFB is the time from the browser’s request until it receives the first byte of the server’s response. It measures server response speed and provides the foundation for all other loading metrics.
Related tool: Web VitalsWebP is a modern image format developed by Google. 25-35% smaller than JPEG at the same quality. Supported by all modern browsers.
Crawling (crawlability) is the ability of search engine bots to crawl website pages. Crawling problems can prevent pages from being indexed.
Related tool: robots.txt analyzerWHOIS is a protocol for obtaining information about a domain owner, registration date, and registrar. It is used to check domains before purchase.
Related tool: WHOIS LookupA 301 redirect permanently forwards a page to a new URL. It passes all link equity and tells search engines that the page address has changed.
Related tool: Redirect checkA 302 redirect temporarily forwards a page. Unlike 301, search engines keep the original URL in the index and do not pass link equity.
Related tool: Redirect check