What is the rendering crawler for
Analyze rendering and JavaScript execution for every page to uncover problems that affect SEO, user experience, and reliability
Detect JavaScript errors and rendering issues that prevent search engines and AI systems to understand and index your relevant pages
Identify performance bottlenecks caused by slow scripts, excessive DOM size, or inefficient resource loading
Analyze differences between downloaded and rendered HTML and understand how search engines crawl, render and index your site
Flawless rendering and JS execution are key for modern websites
Modern websites often rely on rendering JavaScript for dynamic content and interactivity. Our JavaScript crawler helps you to identify and fix rendering and JavaScript execution issues at scale before they impact your users or search visibility. Use our analysis to ensure your site is fast, reliable, and that content is accessible to users, search engines and AI systems.
Rendering error detection features
JavaScript error detection
Automatically detect JavaScript errors and console warnings that occur during page rendering. Identify scripts that fail to execute or are blocked from loading.
Blocked and missing resources
Find resources that fail to load due to Content Security Policy violations, network errors, or incorrect paths. Ensure all critical assets are available for rendering.
DOM and content changes
Track changes to the DOM, titles, meta descriptions, and headings made by JavaScript during rendering. Detect unexpected or missing content after execution.
Client-side redirects
Identify and eliminate unnecessary client-side redirects and meta-refreshes that delay content display and cause accessibility issues for users.
Crawl storage for subsequent analysis
Complete HTML & resource storage
Retrospective debugging of issues is made possible by saving HTML, resources, headers and console logs for all crawls, thus documenting errors and source code.
Show HTML source code for a given hint
Display the HTML source code snippet of many technical SEO hints directly from the saved HTML, without the need to open the source code inside the browser.
Asset caching for high-efficiency crawling
While other crawlers request the same resources again and again, ours caches them and reuses them throughout the crawl, which cuts traffic significantly.
Rendering performance optimization features
Optimize JavaScript Execution
Identify pages with a slow rendering performance or that contain render blocking scripts and optimize their rendering speed to increase user interactions.
Reduce resource bottlenecks
Detect pages with large, uncompressed, or excessive resources that slow down rendering and negatively impact user experience.
Web Vitals Measurements
Get web vitals measurements for your pages, including FCP, LCP, CLS, and more to better understand what causes the underlying performance issues.
Segment-based analysis
Compare rendering and JavaScript execution metrics across different page types or site segments to prioritize optimization efforts.