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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
78
GRADE
C
FIX
1
REVIEW
4
PASS
7
INFO
2

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

Mobile Desktop
85
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
81
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.

738 ms

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

1.21 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.

0.229

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

1.09 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.

1.21 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
14
7 PASS 4 REVIEW 1 FIX
F
Page Weight Budget
Action
10.1 MB transferred, 144 requests
FIX
10.1 MB transferred, 144 requests
Critical::
Page weighs 17.0 MB (10.1 MB transferred)
Warning::
Images are 1.3 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.3 MB
Warning::
JavaScript is 1.2 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.2 MB
Warning::
144 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 2.1 g CO2 per page load
10.1 MB / 2.4 MB budget
10.1 MB transferred
144 requests
2.1 g CO2 per page load
Other 7.3 MiB 72%
Images 1.3 MiB 13%
JavaScript 1.2 MiB 12%
CSS 168.4 KiB 2%
Fonts 67.9 KiB 1%
HTML 31.3 KiB 0%
Other 27.6 KiB 0%
Other 2.8 KiB 0%
Other 232 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

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

C
Image Optimization
Action
58 images, 0 KB saveable
REVIEW
58 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/kong.svg 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/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/logos/Huggingface.... 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/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/gdpr-certific... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.metabase.com/images/icons/Type=Learn.s... 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.
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/product/business-i... 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/home/soc-2-type-1-... 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/profiles/derrick-m... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
58 images 1.3 MB
0 oversized -0 KB
58 legacy format
18 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

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

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

B
JS Execution Cost
948ms total JS execution
REVIEW
948ms total JS execution
Warning::
https://www.metabase.com/: 556ms CPU time
Warning::
Unattributable: 306ms CPU time
Info::
https://vjs.zencdn.net/7.20.3/video.min.js: 85ms CPU time
Info::
Third-party scripts: 392ms (41% of total)

Main Thread Breakdown

Other 42% Style & Layout 21% Script Evaluation 20% Rendering 8% Parse HTML & CSS 4% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://www.metabase.com/556ms24ms1ms1st
Unattributable306ms4ms0ms3rd
https://vjs.zencdn.net/7.20.3/video.min.js85ms41ms18ms3rd
C
JS Bundles
Action
43 scripts, 282 KB unused
REVIEW
43 scripts, 282 KB unused
Warning::
https://vjs.zencdn.net/7.20.3/video.min.js: 117 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 KB117 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://www.metabase.com/js/video-autoplay.js1 KB—✓1st
https://www.metabase.com/js/promo-banner.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.js0 KB—✓1st
https://www.metabase.com/js/ai-newsletter-subscribe-form.js1 KB—✓1st
https://www.metabase.com/js/events/datetime.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
13% third-party, 0 ms blocking
PASS
13% third-party, 0 ms blocking
Info::
Third-party code accounts for 13% of page weight (1.3 MiB of 10.1 MiB)
Info::
Third-party blocking time is low (0 ms)
87%
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 500 ms 1.0 s FCP 738 ms LCP 1.2 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_ROW4AJi8SJQt.woff2L0xuDF4xlVMF-BfR8bXMIhJ... https://fonts.gstatic.com/s/robotomono/v31/L0xuDF4xlVMF-BfR8bXMIhJHg45mwgGEFl0_3vq_ROW4AJi8SJQt.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
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
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
144 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
41% of JavaScript execution is third-party
First-party Third-party 392ms · 159KB · $2/mo
Unattributable
Other
Costly
Execution 306ms
Transfer 0 KB
Monthly Cost $2/mo
vjs.zencdn.net
Other
Optional
Execution 85ms
Transfer 159 KB
Unused 74%
Monthly Cost $0/mo

These scripts may cost more than they're worth

  • Unattributable adds 306ms and costs ~$2/month

41% 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 306ms 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

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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