Loading skill
Install any skill in seconds. Free to start, no credit card required.
Get Started Free →Use when auditing slow page loads, heavy assets, or rendering delays related to Eliminate render-blocking resources. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.
.claude/skills/thedaviddias-render-blocking/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-15 | ✗→✓ | ▲ Improved | -9% | 0% |
| case-01 | ✓→✓ | ＝ Same ✓ | 17% | 0% |
| case-02 | ✓→✓ | ＝ Same ✓ | 24% | 0% |
| case-03 | ✓→✓ | ＝ Same ✓ | 1% | 0% |
| case-04 | ✓→✓ | ＝ Same ✓ | -34% | 0% |
Render-blocking resources prevent the browser from painting anything on the screen, leading to a "white screen" effect and poor user experience.
defer, async, or media queries@import in CSS as it creates serial request chainsReview the page's resources and identify any CSS or JavaScript files that are blocking the initial render of the page.
Update the loading strategy for render-blocking resources by using defer, async, or inlining critical styles.
Explain how render-blocking resources impact the First Contentful Paint (FCP) and how to resolve them.
Review the routes, assets, and loading behavior that affect Eliminate render-blocking resources. Flag exact files, requests, or rendering steps that add unnecessary network, CPU, or layout cost, and describe the measurement method used to confirm the issue.
For full implementation details, code examples, and framework-specific guidance, see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/performance/render-blocking
| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-01 | pass→pass | 5,771 | 4,929 | -15% | 1 | 1 | 0% | 1,059 | 1,244 | +17% | 0 | 0 | — |
case-02 | pass→pass | 4,077 | 4,002 | -2% | 1 | 1 | 0% | 805 | 996 | +24% | 0 | 0 | — |
case-03 | pass→pass | 9,832 | 8,081 | -18% | 1 | 1 | 0% | 1,838 | 1,855 | +1% | 0 | 0 | — |
case-04 | pass→pass | 7,588 | 3,932 | -48% | 1 | 1 | 0% | 1,442 | 947 | -34% | 0 | 0 | — |
case-05 | pass→pass | 8,280 | 7,739 | -7% | 1 | 1 | 0% | 1,627 | 1,804 | +11% | 0 | 0 | — |
case-06 | pass→pass | 5,838 | 4,712 | -19% | 1 | 1 | 0% | 1,202 | 1,199 | -0% | 0 | 0 | — |
case-07 | pass→pass | 5,156 | 3,795 | -26% | 1 | 1 | 0% | 1,053 | 993 | -6% | 0 | 0 | — |
case-08 | pass→pass | 6,572 | 8,555 | +30% | 1 | 1 | 0% | 1,333 | 1,856 | +39% | 0 | 0 | — |
case-09 | pass→pass | 3,369 | 4,966 | +47% | 1 | 1 | 0% | 597 | 1,205 | +102% | 0 | 0 | — |
case-10 | pass→pass | 7,526 | 5,466 | -27% | 1 | 1 | 0% | 1,413 | 1,298 | -8% | 0 | 0 | — |
case-11 | pass→pass | 12,184 | 12,365 | +1% | 1 | 1 | 0% | 2,141 | 2,517 | +18% | 0 | 0 | — |
case-12 | pass→pass | 4,407 | 5,073 | +15% | 1 | 1 | 0% | 844 | 1,196 | +42% | 0 | 0 | — |
case-13 | pass→pass | 4,518 | 3,851 | -15% | 1 | 1 | 0% | 836 | 925 | +11% | 0 | 0 | — |
case-14 | pass→pass | 11,097 | 9,185 | -17% | 1 | 1 | 0% | 1,820 | 1,757 | -3% | 0 | 0 | — |
case-15 | fail→pass | 9,762 | 8,104 | -17% | 1 | 1 | 0% | 1,855 | 1,695 | -9% | 0 | 0 | — |
case-16 | pass→pass | 8,601 | 5,641 | -34% | 1 | 1 | 0% | 1,587 | 1,351 | -15% | 0 | 0 | — |
case-17 | pass→pass | 11,876 | 9,558 | -20% | 1 | 1 | 0% | 2,107 | 1,961 | -7% | 0 | 0 | — |
case-18 | pass→pass | 4,456 | 12,130 | +172% | 1 | 1 | 0% | 822 | 2,507 | +205% | 0 | 0 | — |
case-19 | pass→pass | 12,394 | 7,984 | -36% | 1 | 1 | 0% | 2,204 | 1,848 | -16% | 0 | 0 | — |
case-20 | pass→pass | 5,800 | 4,104 | -29% | 1 | 1 | 0% | 1,173 | 1,104 | -6% | 0 | 0 | — |
case-21 | pass→pass | 12,329 | 11,585 | -6% | 1 | 1 | 0% | 2,548 | 2,664 | +5% | 0 | 0 | — |
case-22 | pass→pass | 6,702 | 3,405 | -49% | 1 | 1 | 0% | 1,273 | 925 | -27% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted. The headline lift of +5 percentage points is the difference between those two pass rates over the 22 comparable cases.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
Other measured skills in the registry, with their headline benchmark lift.