The full leaderboard
Scores below come from Google's PageSpeed Insights API in mobile mode, the same engine that powers Lighthouse. Two runs per URL, median reported. Color tiers follow Google's standard: green for 90 and above, amber for 50 to 89, coral for 0 to 49.
Click VERIFY on any row to open Google PageSpeed Insights with that tool's URL pre-filled. Don't trust these numbers, check them yourself.
Curious how your homepage compares? Drop the URL below and we'll deep-link you straight into Google PageSpeed Insights. No tracking, no signup. The form just builds the URL and opens it in a new tab.
Powered by pagespeed.web.dev - Google's official Lighthouse front end.
| # | Tool | Mobile | Desktop | LCP | TBT | Verify |
|---|---|---|---|---|---|---|
| 1 | Claude SEO USopen source | 99 | 99 | 1.7s | 0ms | VERIFY |
| 2 | MarketMusecontent strategy | 98 | 98 | 1.9s | 0ms | VERIFY |
| 3 | Semrushseo suite | 53 | 68 | 4.8s | 1116ms | VERIFY |
| 4 | Fraseai content briefs | 50 | 67 | 6.7s | 1778ms | VERIFY |
| 5 | RankIQblogger seo | 39 | 57 | 17.7s | 925ms | VERIFY |
| 6 | DataForSEOapi-first | 34 | 52 | 17.7s | 1051ms | VERIFY |
| 7 | Surfer SEOserp optimization | 31 | 60 | 18.7s | 1326ms | VERIFY |
| 8 | Ahrefsbacklink analysis | 26 | 56 | 17.5s | 2880ms | VERIFY |
Last run: - methodology - CC-BY-4.0
Methodology
Every URL is tested with the same engine, same throttling, same device profile. The methodology stays constant across quarterly refreshes so historical comparisons remain valid.
The full URL list and raw data live in the Claude SEO GitHub repo. Republish, quote, or rebuild this report freely - attribution required.
What a slow site actually costs
Speed isn't a feature, it's a revenue lever. Google's own research and the Web Almanac's annual analysis converge on the same conclusion: every additional second on mobile loses customers.
- Bounce probability rises 32% when mobile load time goes from 1 to 3 seconds, and 90% from 1 to 5 seconds (Think with Google).
- Pages meeting Core Web Vitals thresholds show a 24% lower abandonment rate during loading (web.dev).
- Conversion rate drops by an average of 4.42% with each additional second of load time between 0 and 5 seconds (Portent industry benchmark study).
For a SaaS pricing page, that's the difference between a trial signup and a closed tab. For a publisher, it's the difference between a subscriber and a bounce. Half the tools in the table above are leaving money in the parking lot before the visitor even reads the headline.
Largest Contentful Paint - the "is this page even loading" metric
LCP measures how long the largest above-the-fold element takes to render. Google's threshold for "good": 2.5 seconds or less. "Poor" starts at 4 seconds.
In this dataset only 2 of 8 tools hit the good threshold. The bottom of the table sits at 11-22 seconds - many times Google's good cut-off. The villain on those pages is almost always the same culprit: a large hero video, an unoptimized hero image, or a render-blocking third-party script (chat widgets, A/B tests, analytics) competing for the network.
The fix is pedestrian. Resize hero images to actual display dimensions. Serve them as WebP. Add fetchpriority="high". Defer everything that isn't above-the-fold. None of this requires a rewrite. It requires someone running a Lighthouse test and acting on the four "Opportunities" it reports.
Total Blocking Time - the tap-and-wait metric
TBT measures how long the main thread is locked up parsing JavaScript while the user taps and gets no response. Google's threshold for "good": 200ms or less. The bottom of this leaderboard sits at over 1 second of pure tap-and-wait.
TBT correlates almost perfectly with how many marketing pixels a site loads on first paint. Every analytics SDK, every retargeting tag, every chat widget adds tens to hundreds of milliseconds. Most of them could load lazily after the user has scrolled or interacted - but they don't, because the marketing team set them up and the engineering team didn't push back.
Mobile is where Google actually ranks
Some of the worst-scoring homepages here look fine on desktop. That's the trap. Google has been mobile-first since 2020 and went mobile-only for indexing in 2024. The desktop column on this leaderboard is informational. Only mobile counts for ranking.
This is why the report ranks by mobile and lists desktop as a secondary column. A tool with 96 desktop and 47 mobile is failing the version of the page Google indexes.
Why claude-seo.md ranks #1
We hit a stable median of 99 across three back-to-back PSI runs. MarketMuse hit a stable 98. The other six tools all dropped below 60. The 1-point lead at the top isn't the headline. The 40+ point cliff to the rest of the field is. Here's exactly what this site does. None of it requires a framework upgrade or a CDN migration.
- All CSS and JavaScript inlined. Zero external bundles. Zero render-blocking
<link>tags beyond two web fonts loaded withdisplay=optional. The browser has everything it needs to paint after the HTML arrives. - WebP for every image. Hero images use
fetchpriority="high"anddecoding="async". Below-fold images useloading="lazy". Cache-Control: max-age=31536000, immutableon the/assets/**directory viavercel.json. Returning visitors get every asset from disk cache.- No analytics scripts. No chat widgets. No marketing automation. No A/B testing SDK. The page that's shown to a visitor is the page the developer wrote, not the page after the marketing team's fifteen pixels finish booting.
- System fonts as the fallback path. If Google Fonts is slow, the browser renders Space Grotesk's system fallback in zero milliseconds. No FOIT, no FOUT, no waiting.
- No JavaScript framework. Single-file static HTML. The entire site builds in zero seconds because there's nothing to build. Every byte is intentional.
The full source for this site is on GitHub under MIT license. Copy it. Strip out the SEO content. Put your own product on top. The skeleton is the point.