Web Checker: SEO & Speed

Audit page size, DOM complexity, on-page SEO, and Core Web Vitals. Dual-mode: SERP comparison or single-page CWV diagnostic.

Web Checker: SEO & Speed is a lightweight technical audit tool for SEO consultants, agencies, and website owners who need to check a page's "weight" fast — either comparing rivals on Google Search, or diagnosing any page you're currently viewing. Two Modes, One Extension 📊 SERP Comparison Mode — open a Google search results page and get, for each of the top 10 organic results: decoded + transfer HTML size, DOM element count, title length, H1 presence, an automatic WAF/Cloudflare challenge detector so blocked pages don't skew your data, a relative SEO Weight Score (0-100) against the batch average, and one-click CSV export for client reports. ⚡ Core Web Vitals Mode — open any regular page and get LCP, CLS, TTFB, and FCP rated against Google's official thresholds, a full page-weight measurement (HTML+CSS+JS+images+fonts), a resource breakdown by type with visual bars, a complete sortable resource list flagging the heaviest files, plain-English fix suggestions under each metric, and a composite Speed Score estimate. Why use it? 100% free, no account, no usage limits All processing happens on your device — nothing is sent to an external server Lightweight — vanilla JS, no heavy frameworks Best for: SEO/SEM consultants, digital marketing agencies, and small-to-medium website owners who want a fast technical audit without subscribing to an expensive tool.