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https://spec.org

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
93
GRADE
A
FIX
2
REVIEW
2
PASS
11
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
84
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
95
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

2.92 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

3.68 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

0 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.004

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

2.92 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

3.71 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
17
11 PASS 2 REVIEW 2 FIX
D
Third-Party Impact
Action
70% third-party, 0 ms blocking
FIX
70% third-party, 0 ms blocking
Warning::
Third-party code accounts for 70% of page weight (229.7 KiB of 328.3 KiB)
Info::
Third-party blocking time is low (0 ms)
30%
70%
First-party Third-party
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

B
Image Optimization
12 images, 0 KB saveable
REVIEW
12 images, 0 KB saveable
Warning::
https://spec.org/images/SPECportraitWhiteTM.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.spec.org/images/SPEClogoWhiteTM.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
12 images 181 KB
0 oversized -0 KB
2 legacy format
2 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Page Weight Budget
328 KB transferred, 19 requests
PASS
328 KB transferred, 19 requests
Info::
Page weighs 350 KB (328 KB transferred)
Info::
19 HTTP requests
Info::
Estimated 0.07 g CO2 per page load
328 KB / 2.4 MB budget
328 KB transferred
19 requests
0.07 g CO2 per page load
Images 181.2 KiB 55%
Fonts 53.0 KiB 16%
CSS 50.1 KiB 15%
HTML 42.8 KiB 13%
Other 1.1 KiB 0%
0 2.4 MB 4.9 MB
Under budget
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
JS Execution Cost
498ms total JS execution
PASS
498ms total JS execution
Warning::
https://spec.org/: 318ms CPU time
Info::
Unattributable: 180ms CPU time
Info::
Third-party scripts: 180ms (36% of total)

Main Thread Breakdown

Style & Layout 44% Other 43% Rendering 6% Script Evaluation 4% Parse HTML & CSS 3%
ScriptTotalScriptingParse/CompileParty
https://spec.org/318ms10ms1ms1st
Unattributable180ms6ms0ms3rd
A+
Font Loading
2 fonts (53 KB)
PASS
2 fonts (53 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

53 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s FCP 2.9 s LCP 3.7 shttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 36.7 KiB — 10 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMaxKUBHMdazTgWw.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMaxKUBHMdazTgWw.woff2 — 16.3 KiB — 12 ms — font-display: swap
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 37 KB
Load time 10 ms
Start 130 ms
Risk FOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 16 KB
Load time 12 ms
Start 130 ms
Risk FOUT — text flashes from fallback to web font
Optimization checklist
  • Preload critical fonts (priority=high)
  • Use woff2 format for all fonts
  • Set font-display to swap, optional, or fallback
  • Subset large fonts (≤100 KB each)
A+
JS Bundles
No JavaScript
PASS
No JavaScript
Info::
No JavaScript bundles
No JavaScript files loaded.
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A
Page Weight Inventory
19 resources · 328 KB · 0 KB savings available
PASS
19 resources · 328 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 328 KB
Warning::
12 third-party resources (70% of weight)
19 resources · 328.3 KiB · 12 third-party Within 1MB page-weight target
Image 56% · 182.3 KiB
Font 16% · 53.0 KiB
CSS 15% · 50.1 KiB
Document 13% · 42.8 KiB
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
Network Waterfall
19 requests over 181ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 2.9 s LCP 3.7 shttps://spec.org// https://spec.org/ — 200 — 42.8 KiB — 46 ms — http/1.1https://fonts.googleapis.com/css?family=Roboto:400,400i,700,700i&display=swapfonts.googleapis.com/css?family=Rob... https://fonts.googleapis.com/css?family=Roboto:400,400i,700,700i&display=swap — 200 — 2.3 KiB — 44 ms — h2https://fonts.googleapis.com/css?family=Source+Code+Pro:400,400i,600&display=swapfonts.googleapis.com/css?family=Sou... https://fonts.googleapis.com/css?family=Source+Code+Pro:400,400i,600&display=swap — 200 — 892 B — 43 ms — h2https://spec.org/css/Minimus.min.7762ae9d1fe6c878fabc886a392ecf0c763b1087924dde1229a1d4e2f4dd0aab.css/css/Minimus.min.7762ae9d1fe6c878fa... https://spec.org/css/Minimus.min.7762ae9d1fe6c878fabc886a392ecf0c763b1087924dde1229a1d4e2f4dd0aab.css — 200 — 47.0 KiB — 11 ms — http/1.1https://www.spec.org/images/SPEClogoWhiteTM.svgwww.spec.org/images/SPEClogoWhiteTM... https://www.spec.org/images/SPEClogoWhiteTM.svg — 200 — 5.7 KiB — 66 ms — http/1.1https://spec.org/images/SPECportraitWhiteTM.svg/images/SPECportraitWhiteTM.svg https://spec.org/images/SPECportraitWhiteTM.svg — 200 — 5.7 KiB — 12 ms — http/1.1https://spec.org/images/social/xlogo20x20.webp/images/social/xlogo20x20.webp https://spec.org/images/social/xlogo20x20.webp — 200 — 858 B — 15 ms — http/1.1https://spec.org/images/social/linkedin20x20.webp/images/social/linkedin20x20.webp https://spec.org/images/social/linkedin20x20.webp — 200 — 592 B — 21 ms — http/1.1https://spec.org/images/social/facebook20x20.webp/images/social/facebook20x20.webp https://spec.org/images/social/facebook20x20.webp — 200 — 551 B — 25 ms — http/1.1https://www.spec.org/ThinkingTech-HeroImage_hu155598c248982bd9cc4b148d0fb12269_305190_1920x512_fill_q75_h2_box_smart1.webpwww.spec.org/ThinkingTech-HeroImage... https://www.spec.org/ThinkingTech-HeroImage_hu155598c248982bd9cc4b148d0fb12269_305190_1920x512_fill_q75_h2_box_smart1.webp — 200 — 67.5 KiB — 86 ms — http/1.1https://www.spec.org/blog/2026/snxbenchmarking/torpedo_retriever_IconImage_hubda700b4ec1de422c9bbb27afa649df8_102662_500x309_fill_q75_h2_box_smart1_3.webpwww.spec.org/blog/2026/snxbenchmark... https://www.spec.org/blog/2026/snxbenchmarking/torpedo_retriever_IconImage_hubda700b4ec1de422c9bbb27afa649df8_102662_500x309_fill_q75_h2_box_smart1_3.webp — 200 — 13.4 KiB — 28 ms — http/1.1https://www.spec.org/blog/2025/specviewperf15/torpedo_retriever_IconImage_hubda700b4ec1de422c9bbb27afa649df8_102662_500x309_fill_q75_h2_box_smart1_3.webpwww.spec.org/blog/2025/specviewperf... https://www.spec.org/blog/2025/specviewperf15/torpedo_retriever_IconImage_hubda700b4ec1de422c9bbb27afa649df8_102662_500x309_fill_q75_h2_box_smart1_3.webp — 200 — 13.4 KiB — 44 ms — http/1.1https://www.spec.org/blog/2025/cloudbenchmarkupdate/cloudupdate-IconImage_huaab0b850739c7f29a7974f555186ab97_4454106_500x309_fill_q75_h2_box_smart1.webpwww.spec.org/blog/2025/cloudbenchma... https://www.spec.org/blog/2025/cloudbenchmarkupdate/cloudupdate-IconImage_huaab0b850739c7f29a7974f555186ab97_4454106_500x309_fill_q75_h2_box_smart1.webp — 200 — 21.3 KiB — 43 ms — http/1.1https://www.spec.org/blog/2025/specadvocacy/greenmaplightbulb-IconImage_hu99351847bf76365ed01cc2e7d255e759_589363_500x309_fill_q75_h2_box_smart1.webpwww.spec.org/blog/2025/specadvocacy... https://www.spec.org/blog/2025/specadvocacy/greenmaplightbulb-IconImage_hu99351847bf76365ed01cc2e7d255e759_589363_500x309_fill_q75_h2_box_smart1.webp — 200 — 18.1 KiB — 44 ms — http/1.1https://www.spec.org/blog/2025/icpe2025/icpe20253-IconImage_hu75da5cdf2a7a88157e2e5f0301d9c36a_53031_500x309_fill_q75_h2_box_smart1.webpwww.spec.org/blog/2025/icpe2025/icp... https://www.spec.org/blog/2025/icpe2025/icpe20253-IconImage_hu75da5cdf2a7a88157e2e5f0301d9c36a_53031_500x309_fill_q75_h2_box_smart1.webp — 200 — 17.9 KiB — 45 ms — http/1.1https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2fonts.gstatic.com/s/roboto/v51/KFO7... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 200 — 36.7 KiB — 10 ms — h3https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMaxKUBHMdazTgWw.woff2fonts.gstatic.com/s/roboto/v51/KFO7... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMaxKUBHMdazTgWw.woff2 — 200 — 16.3 KiB — 12 ms — h3https://www.spec.org/blog/2025/cpu2017-story/gem5_microscope-IconImage_hu87424cfdcd4d728c2b54263c7fe68487_133116_500x309_fill_q75_h2_box_smart1_3.webpwww.spec.org/blog/2025/cpu2017-stor... https://www.spec.org/blog/2025/cpu2017-story/gem5_microscope-IconImage_hu87424cfdcd4d728c2b54263c7fe68487_133116_500x309_fill_q75_h2_box_smart1_3.webp — 200 — 16.3 KiB — 30 ms — http/1.1https://spec.org/favicon.ico/favicon.ico https://spec.org/favicon.ico — 200 — 1.1 KiB — 13 ms — http/1.1
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
36% of JavaScript execution is third-party
First-party Third-party 180ms · 0KB · $1/mo
Unattributable
Other
Optional
Execution 180ms
Transfer 0 KB
Monthly Cost $1/mo

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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