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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
78
GRADE
C
FIX
2
REVIEW
3
PASS
9
INFO
2

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

Mobile Desktop
55
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
80
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
92
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.

5.50 s

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

6.97 s

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

288 ms

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

0.000

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

6.46 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.

12.43 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
16
9 PASS 3 REVIEW 2 FIX
F
Page Weight Budget
Action
7.0 MB transferred, 137 requests
FIX
7.0 MB transferred, 137 requests
Critical::
Page weighs 12.9 MB (7.0 MB transferred)
Warning::
JavaScript is 1.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.1 MB
Warning::
137 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 1.5 g CO2 per page load
7.0 MB / 2.4 MB budget
7.0 MB transferred
137 requests
1.5 g CO2 per page load
Other 4.6 MiB 66%
JavaScript 1.1 MiB 16%
Images 1001.8 KiB 14%
CSS 168.5 KiB 2%
Fonts 67.9 KiB 1%
HTML 31.3 KiB 0%
Other 27.4 KiB 0%
Other 2.8 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

F
JS Execution Cost
Action
4661ms total JS execution
FIX
4661ms total JS execution
Warning::
Unattributable: 1665ms CPU time
Warning::
https://www.metabase.com/: 1588ms CPU time
Warning::
https://vjs.zencdn.net/7.20.3/video.min.js: 423ms CPU time
Warning::
https://www.metabase.com/js/tabs-with-timer.js: 347ms CPU time
Warning::
https://www.metabase.com/js/video-autoplay.js: 278ms CPU time
Warning::
Third-party scripts: 2449ms (53% of total)

Main Thread Breakdown

Other 51% Script Evaluation 21% Style & Layout 13% Rendering 5% Parse HTML & CSS 5% Script Parsing & Compilation 3%
ScriptTotalScriptingParse/CompileParty
Unattributable1665ms23ms0ms3rd
https://www.metabase.com/1588ms87ms4ms1st
https://vjs.zencdn.net/7.20.3/video.min.js423ms200ms46ms3rd
https://www.metabase.com/js/tabs-with-timer.js347ms198ms0ms1st
https://www.metabase.com/js/video-autoplay.js278ms225ms0ms1st
https://browser.sentry-cdn.com/7.80.0/bundle.tracing.min.js104ms82ms8ms3rd
https://unpkg.com/@lottiefiles/lottie-player@1.5.7/dist/lottie-player.js87ms37ms44ms3rd
https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js60ms49ms10ms3rd
https://s3.amazonaws.com/downloads.mailchimp.com/js/mc-validate.js58ms40ms11ms3rd
https://unpkg.com/imagesloaded@5/imagesloaded.pkgd.min.js53ms34ms1ms3rd
C
Image Optimization
Action
55 images, 0 KB saveable
REVIEW
55 images, 0 KB saveable
Warning::
https://www.metabase.com/images/chevron_blue_right... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/mcdonalds.sv... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/huma.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/home/airbyte... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/betterment.s... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/deutsche-tel... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/icons/curved-arrow... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/home/soc-2-type-1-... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/capital-one.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/kong.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/home/gdpr-certific... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/home/ccpa-certific... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/logos/Huggingface.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/profiles/derrick-m... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/home/demo.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/home/soc-2-type-2-... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
55 images 1002 KB
0 oversized -0 KB
54 legacy format
17 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

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

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

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

Set explicit width and height to prevent CLS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

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

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

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
JS Bundles
Action
40 scripts, 282 KB unused
REVIEW
40 scripts, 282 KB unused
Warning::
https://vjs.zencdn.net/7.20.3/video.min.js: 118 KB unused (74%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://s3.amazonaws.com/downloads.mailchimp.com/j...: 90 KB unused (65%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://unpkg.com/@lottiefiles/lottie-player@1.5.7...: 74 KB unused (86%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 282 KB
282 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://vjs.zencdn.net/7.20.3/video.min.js159 KB118 KB (74%)✓3rd
https://s3.amazonaws.com/downloads.mailchimp.com/js/mc-validate.js140 KB90 KB (65%)✓3rd
https://unpkg.com/@lottiefiles/lottie-player@1.5.7/dist/lottie-player.js86 KB74 KB (86%)✓3rd
https://unpkg.com/tippy.js@6.3.7/dist/tippy-bundle.umd.js19 KB—✓3rd
https://www.metabase.com/js/status.js1 KB—✓1st
https://www.metabase.com/js/add-params-to-anchors.js1 KB—✓1st
https://www.metabase.com/js/pass-referral-params-to-fillout-forms.js1 KB—✓1st
https://www.metabase.com/js/ai-newsletter-subscribe-form.js1 KB—✓1st
https://www.metabase.com/js/github-stars.js1 KB—✓1st
https://www.metabase.com/js/main-nav.js1 KB—✓1st

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

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

Green Hosting

No green hosting detected

A+
Third-Party Impact
18% third-party, 0 ms blocking
PASS
18% third-party, 0 ms blocking
Info::
Third-party code accounts for 18% of page weight (1.3 MiB of 7.0 MiB)
Info::
Third-party blocking time is low (0 ms)
82%
18%
First-party Third-party
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+
Font Loading
5 fonts (68 KB)
PASS
5 fonts (68 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

68 KB total

Render-blocking

0

of 5

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 4.0 s 5.0 s 6.0 s 7.0 s FCP 5.5 s LCP 7.0 shttps://fonts.gstatic.com/s/lato/v25/S6u9w4BMUTPHh6UVSwiPGQ3q5d0.woff2S6u9w4BMUTPHh6UVSwiPGQ3... https://fonts.gstatic.com/s/lato/v25/S6u9w4BMUTPHh6UVSwiPGQ3q5d0.woff2 — 13.9 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/lato/v25/S6uyw4BMUTPHjx4wXiWtFCc.woff2S6uyw4BMUTPHjx4wXiWtFCc... https://fonts.gstatic.com/s/lato/v25/S6uyw4BMUTPHjx4wXiWtFCc.woff2 — 13.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/robotomono/v31/L0xuDF4xlVMF-BfR8bXMIhJHg45mwgGEFl0_3vq_ROW4AJ68SA.woff2L0xuDF4xlVMF-BfR8bXMIhJ... https://fonts.gstatic.com/s/robotomono/v31/L0xuDF4xlVMF-BfR8bXMIhJHg45mwgGEFl0_3vq_ROW4AJ68SA.woff2 — 12.4 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/lato/v25/S6u8w4BMUTPHjxsAXC-qNiXg7Q.woff2S6u8w4BMUTPHjxsAXC-qNiX... https://fonts.gstatic.com/s/lato/v25/S6u8w4BMUTPHjxsAXC-qNiXg7Q.woff2 — 14.5 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/lato/v25/S6u9w4BMUTPHh50XSwiPGQ3q5d0.woff2S6u9w4BMUTPHh50XSwiPGQ3... https://fonts.gstatic.com/s/lato/v25/S6u9w4BMUTPHh50XSwiPGQ3q5d0.woff2 — 13.4 KiB — 0 ms — font-display: swap
S6u9w4BMUTPHh6UVSwiPGQ3... woff2 swap
Size 14 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
S6uyw4BMUTPHjx4wXiWtFCc... woff2 swap
Size 14 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
L0xuDF4xlVMF-BfR8bXMIhJ... woff2 swap
Size 12 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
S6u8w4BMUTPHjxsAXC-qNiX... woff2 swap
Size 15 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
S6u9w4BMUTPHh50XSwiPGQ3... woff2 swap
Size 13 KB
Load time 0 ms
Start 0 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+
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
3 hints, 0 missing preconnects
PASS
3 hints, 0 missing preconnects
Info::
Page uses 3 resource hint(s)

Current Resource Hints

preconnect
3
preload
—
dns-prefetch
—
prefetch
—

3 resource hints configured

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
A+
HTTP Caching
max-age=600 (10 minutes)
PASS
max-age=600 (10 minutes)
Info::
Cache-Control header is set
Got: max-age=600
Info::
Effective TTL: 10 minutes (max-age=600)
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present
Cache-Control

max-age=600

DirectiveValueMeaning
max-age600Cache for 10 minutes
Effective TTL: 600 seconds
Network Waterfall
137 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
53% of JavaScript execution is third-party
First-party Third-party 2449ms · 452KB · $14/mo
Unattributable
Other
Costly
Execution 1665ms
Transfer 0 KB
Monthly Cost $10/mo
vjs.zencdn.net
Other
Costly
Execution 423ms
Transfer 159 KB
Unused 74%
Monthly Cost $2/mo
browser.sentry-cdn.com
Other
Optional
Execution 104ms
Transfer 30 KB
Monthly Cost $1/mo
unpkg
CDN
Optional
Execution 87ms
Transfer 86 KB
Unused 86%
Monthly Cost $0/mo
cdnjs
CDN
Optional
Execution 60ms
Transfer 36 KB
Monthly Cost $0/mo
s3.amazonaws.com
Other
Optional
Execution 58ms
Transfer 140 KB
Unused 65%
Monthly Cost $0/mo
unpkg
CDN
Optional
Execution 53ms
Transfer 0 KB
Monthly Cost $0/mo

These scripts may cost more than they're worth

  • Unattributable adds 1665ms and costs ~$10/month
  • vjs.zencdn.net adds 423ms and costs ~$2/month

53% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 1665ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

vjs.zencdn.net takes 423ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

74% of vjs.zencdn.net's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

86% of unpkg's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

65% of s3.amazonaws.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

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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