Website Speed Test
Test your website speed instantly with RankNibbler's built-in performance checker. When you run an SEO audit on the homepage, the Performance tab automatically runs a Google PageSpeed Insights test and shows your results — no separate tool needed.
What the Speed Test Checks
RankNibbler's Performance tab uses Google's official PageSpeed Insights API to test your page. This is the same data Google uses to evaluate your site for ranking purposes. The test returns:
Performance Scores (0-100)
| Score | Category | What It Tests |
|---|---|---|
| Performance | Page speed | LCP, FCP, TBT, CLS, Speed Index |
| Accessibility | Usability | Contrast, labels, ARIA, semantic HTML |
| Best Practices | Code quality | HTTPS, console errors, image format, deprecated APIs |
| SEO | Search optimisation | Meta tags, crawlability, mobile-friendliness |
Core Web Vitals
- Largest Contentful Paint (LCP) — loading speed of main content
- Cumulative Layout Shift (CLS) — visual stability during loading
- Total Blocking Time (TBT) — proxy for Interaction to Next Paint (INP)
- First Contentful Paint (FCP) — time to first visible content
- Speed Index — how quickly content is visually loaded
- Time to Interactive — when the page becomes fully interactive
Opportunities
Specific recommendations to improve performance, ranked by potential time savings. Common opportunities include compressing images, removing unused CSS, deferring offscreen images, and reducing JavaScript execution time.
Diagnostics
Additional information about your page's performance characteristics that may not directly affect the score but indicate areas for improvement.
How to Run a Speed Test
- Go to the RankNibbler homepage
- Enter your URL and click Analyse
- Wait for the SEO audit to complete (a few seconds)
- Click the Performance tab — the speed test runs automatically in the background
- Results appear in 10-20 seconds with scores, metrics, and recommendations
The speed test runs on mobile configuration by default, since Google uses mobile-first indexing. The test is powered by Google's PageSpeed Insights API — the same data available at pagespeed.web.dev, integrated directly into your RankNibbler audit.
Understanding Your Results
| Score | Rating | Action |
|---|---|---|
| 90 - 100 | Fast | Excellent performance. Minor tweaks possible but not urgent. |
| 50 - 89 | Average | Room for improvement. Focus on the opportunities listed. |
| 0 - 49 | Slow | Significant issues. Address the top opportunities immediately. |
How to Improve Your Speed Score
The most effective improvements for most websites:
- Optimise images — compress, resize, use WebP, add lazy loading
- Defer non-critical JavaScript — use async or defer on all scripts that are not needed for initial render
- Reduce external resources — fewer CSS and JS files means fewer network requests
- Set image dimensions — prevents CLS
- Use a CDN — serve content from servers close to your users
- Enable compression — GZIP or Brotli compression on your server
For a comprehensive guide, see how to reduce page load time.
Speed Test vs Full SEO Audit
The speed test is just one part of what RankNibbler checks. The full audit also covers on-page SEO factors like title tags, meta descriptions, headings, images, links, structured data, keyword density, readability, tech stack, and accessibility — over 30 checks in total. The Performance tab adds Google's speed analysis on top of all that.
Last updated: March 2026