Glossary
Technical terms explained
Canonical URL
A canonical URL is the preferred version of a web page when multiple URLs have similar or duplicate content. It's specified using a canonical link element in the HTML head to tell search engines which version to index.
CLS (Cumulative Layout Shift)
A Core Web Vital metric that measures visual stability. It quantifies how much content shifts unexpectedly during page load. Lower scores are better. Good: < 0.1, Needs Improvement: 0.1-0.25, Poor:> 0.25.
Code Snippet
A pattern of code (defined by regex) that you want to monitor on your web pages. Commonly used for tracking analytics codes, pixels, or custom scripts.
CrUX (Chrome User Experience Report)
Google's dataset of real user performance metrics collected from Chrome users. Provides authentic user experience data for Core Web Vitals metrics.
FCP (First Contentful Paint)
A Core Web Vital metric measuring when the first text or image is painted. Good: < 1.8s, Needs Improvement: 1.8s-3s, Poor:> 3s.
INP (Interaction to Next Paint)
A Core Web Vital metric replacing FID, measuring responsiveness to user interactions. Good: < 200ms, Needs Improvement: 200ms-500ms, Poor:> 500ms.
JSON-LD
JavaScript Object Notation for Linked Data. A method of encoding structured data using JSON format, commonly used for schema.org markup to help search engines understand page content.
LCP (Largest Contentful Paint)
A Core Web Vital metric measuring loading performance. Marks when the largest content element becomes visible. Good: < 2.5s, Needs Improvement: 2.5s-4s, Poor:> 4s.
Meta Robots
HTML meta tag that provides instructions to search engine crawlers about indexing and following links. Common values include "noindex", "nofollow", "noarchive".
Origin vs URL (CrUX)
Origin represents the entire domain (e.g., example.com), while URL is page-specific (e.g., example.com/page). CrUX provides both when available, falling back to origin for low-traffic pages.
Retrigger
A manual, on-demand check of a URL outside the scheduled monitoring interval. Used to immediately verify changes or investigate issues.
Robots.txt
A file placed at the root of a website that provides instructions to web crawlers about which pages or sections should not be crawled or indexed.
TTFB (Time to First Byte)
A Core Web Vital metric measuring server responsiveness - the time from navigation to receiving the first byte of content. Good: < 800ms, Needs Improvement: 800ms-1800ms, Poor:> 1800ms.
X-Robots-Tag
An HTTP header alternative to meta robots tags, providing the same indexing instructions to search engines but applied at the server level rather than in HTML.