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https://Bili.works

Performance

· 26 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
83
GRADE
B
FIX
3
REVIEW
7
PASS
13
INFO
3

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

Mobile Desktop
48
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
96
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
91
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.

4.14 s

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

14.11 s

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

604 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.

5.17 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.

14.11 s

Page Load Progression

573 ms
1.1 s
1.7 s
2.3 s
2.9 s
3.4 s
4.0 s
4.6 s
Checks
26
13 PASS 7 REVIEW 3 FIX
D
Page Weight Budget
Action
2.3 MB transferred, 30 requests
FIX
2.3 MB transferred, 30 requests
Info::
Page weighs 4.5 MB (2.3 MB transferred)
Warning::
Images are 1.2 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.2 MB
Warning::
JavaScript is 790 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 790 KB
Info::
Fonts are 229 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 229 KB
Info::
30 HTTP requests
Info::
Estimated 0.47 g CO2 per page load
2.3 MB / 2.4 MB budget
2.3 MB transferred
30 requests
0.47 g CO2 per page load
Images 1.2 MiB 53%
JavaScript 789.5 KiB 34%
Fonts 229.0 KiB 10%
CSS 55.5 KiB 2%
HTML 12.0 KiB 1%
Other 5.4 KiB 0%
Other 545 B 0%
0 2.4 MB 4.9 MB
Approaching limit

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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

D
JS Execution Cost
Action
2342ms total JS execution
FIX
2342ms total JS execution
Warning::
https://bili.works/: 539ms CPU time
Warning::
Unattributable: 510ms CPU time
Warning::
https://www.googletagmanager.com/gtag/js?id=G-HHL3...: 469ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-TWM...: 356ms CPU time
Warning::
https://bili.works/cookie-banner/silktide-consent-...: 327ms CPU time
Warning::
Third-party scripts: 1475ms (63% of total)

Main Thread Breakdown

Script Evaluation 44% Other 27% Style & Layout 17% Script Parsing & Compilation 8% Rendering 3%
ScriptTotalScriptingParse/CompileParty
https://bili.works/539ms29ms10ms1st
Unattributable510ms158ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-HHL341VPJT&cx=c&gtm=4e6562469ms369ms97ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5S356ms280ms65ms3rd
https://bili.works/cookie-banner/silktide-consent-manager.js327ms62ms7ms1st
https://cdn.deftform.com/embed.js140ms127ms5ms3rd
D
JS Bundles
Action
11 scripts, 196 KB unused
FIX
11 scripts, 196 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-HHL3...: 67 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-TWM...: 65 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-TWM...: 65 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://bili.works/cookie-banner/silktide-consent-...: unminified — 2 KB could be saved
Info::
Total unused JavaScript: 196 KB
196 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-HHL341VPJT&cx=c&gtm=4e6562157 KB67 KB (43%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5S119 KB65 KB (55%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5S119 KB65 KB (55%)✓3rd
https://bili.works/cookie-banner/silktide-consent-manager.js8 KB—✗1st
https://cdn.deftform.com/embed.js12 KB—✓3rd
https://cdn.deftform.com/scripts/nice-select2.js3 KB—✓3rd
https://cdn.deftform.com/scripts/iframe-resizer.child.js14 KB—✓3rd
https://share.deftform.com/build/assets/app-DXvwXSXm.js136 KB—✓3rd
https://share.deftform.com/flux/flux.min.js?id=65fdfb3161 KB—✓3rd
https://scripts.simpleanalyticscdn.com/latest.js5 KB—✓3rd

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
Image Optimization
Action
6 images, 0 KB saveable
REVIEW
6 images, 0 KB saveable
Warning::
https://bili.works/images/bili-logo.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://bili.works/images/hero-examples-wide.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
6 images 1.2 MB
0 oversized -0 KB
6 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

B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
HTTP/3 (QUIC) is not advertised
HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Main HTML Cache-Control
Main HTML max-age=600 (~10min)
REVIEW
Main HTML max-age=600 (~10min)
Info::
Main HTML cached for 10 minutes -- mild staleness risk
Got: max-age=600
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
No Server-Timing header found
Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.
C
Page Weight Inventory
Action
30 resources · 2.3 MB · 196 KB savings available
REVIEW
30 resources · 2.3 MB · 196 KB savings available
Warning::
Page weight 2.3 MB exceeds 1 MB target by 1.3 MB
Got: 2.3 MB Expected: ≤ 1 MB
Info::
~196 KB of savings available
Info::
19 third-party resources (37% of weight)
Info::
3 resources over 200KB
30 resources · 2.3 MiB · 19 third-party 1.3 MiB over 1MB target
Image 53% · 1.2 MiB
JavaScript 34% · 789.5 KiB
Font 10% · 229.0 KiB
CSS 2% · 55.5 KiB
Document 1% · 17.4 KiB
Other 0% · 545 B

~196.3 KiB of savings available

Remove unused JavaScript: 196.3 KiB
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Third-Party Impact
37% third-party, 0 ms blocking
PASS
37% third-party, 0 ms blocking
Info::
Third-party code accounts for 37% of page weight (844.4 KiB of 2.3 MiB)
Info::
Third-party blocking time is low (0 ms)
63%
37%
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
2 fonts (229 KB)
PASS
2 fonts (229 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

229 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 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s FCP 4.1 s LCP 14.1 shttps://bili.works/fonts/DieGrotesk-A-Regular.otfDieGrotesk-A-Regular.otf https://bili.works/fonts/DieGrotesk-A-Regular.otf — 122.8 KiB — 156 ms — font-display: swaphttps://bili.works/fonts/DieGrotesk-A-Medium.otfDieGrotesk-A-Medium.otf https://bili.works/fonts/DieGrotesk-A-Medium.otf — 106.2 KiB — 150 ms — font-display: swap
DieGrotesk-A-Regular.otf otf swap
Size 123 KB
Load time 156 ms
Start 339 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
DieGrotesk-A-Medium.otf otf swap
Size 106 KB
Load time 150 ms
Start 340 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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)

Fixing the unchecked items could save ~183 KB and ~366 ms

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+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+
Server Response Intelligence
2 server-response signal(s) detected
PASS
2 server-response signal(s) detected
Info::
`Vary` header declared: Accept-Encoding
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
Both `ETag` and `Last-Modified` present -- efficient revalidation supported
The page returns both `ETag` (content hash) and `Last-Modified` (timestamp) headers. Browsers can issue conditional GETs with `If-None-Match` or `If-Modified-Since`; the server returns 304 Not Modified for unchanged content, saving bandwidth. ETag is the more reliable of the two (timestamps fail in DST transitions and clock skew).
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
JavaScript Blocking
1 JS blocking issue(s) detected
PASS
1 JS blocking issue(s) detected
Warning::
2 render-blocking <script src> tag(s) without async/defer
Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
No CSS performance depth issues 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
30 requests over 1336ms
INFO
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s FCP 4.1 s LCP 14.1 shttps://bili.works// https://bili.works/ — 200 — 4.4 KiB — 11 ms — h2https://bili.works/cookie-banner/silktide-consent-manager.css/cookie-banner/silktide-consent-man... https://bili.works/cookie-banner/silktide-consent-manager.css — 200 — 2.7 KiB — 126 ms — h2https://bili.works/cookie-banner/silktide-consent-manager.js/cookie-banner/silktide-consent-man... https://bili.works/cookie-banner/silktide-consent-manager.js — 200 — 7.9 KiB — 129 ms — h2https://bili.works/styles.css/styles.css https://bili.works/styles.css — 200 — 5.3 KiB — 122 ms — h2https://bili.works/images/bili-logo.svg/images/bili-logo.svg https://bili.works/images/bili-logo.svg — 200 — 655 B — 117 ms — h2https://bili.works/images/hero-examples-wide.png/images/hero-examples-wide.png https://bili.works/images/hero-examples-wide.png — 200 — 253.0 KiB — 148 ms — h2https://cdn.deftform.com/embed.jscdn.deftform.com/embed.js https://cdn.deftform.com/embed.js — 200 — 12.2 KiB — 45 ms — h2https://bili.works/images/team.jpg/images/team.jpg https://bili.works/images/team.jpg — 200 — 373.4 KiB — 145 ms — h2https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5Swww.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5S — 200 — 118.6 KiB — 49 ms — h2https://share.deftform.com/81e07bb4-0eef-4512-a253-a3af04bed541?embed=1&align=center&parentUrl=https%3A%2F%2Fbili.works%2F&parentReferrer=share.deftform.com/81e07bb4-0eef-45... https://share.deftform.com/81e07bb4-0eef-4512-a253-a3af04bed541?embed=1&align=center&parentUrl=https%3A%2F%2Fbili.works%2F&parentReferrer= — 200 — 7.6 KiB — 174 ms — h2https://bili.works/images/hero-background.png/images/hero-background.png https://bili.works/images/hero-background.png — 200 — 579.9 KiB — 176 ms — h2https://bili.works/fonts/DieGrotesk-A-Regular.otf/fonts/DieGrotesk-A-Regular.otf https://bili.works/fonts/DieGrotesk-A-Regular.otf — 200 — 122.8 KiB — 156 ms — h2https://bili.works/fonts/DieGrotesk-A-Medium.otf/fonts/DieGrotesk-A-Medium.otf https://bili.works/fonts/DieGrotesk-A-Medium.otf — 200 — 106.2 KiB — 150 ms — h2https://www.googletagmanager.com/gtag/js?id=G-HHL341VPJT&cx=c&gtm=4e6562www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-HHL341VPJT&cx=c&gtm=4e6562 — 200 — 156.8 KiB — 44 ms — h2https://cdn.deftform.com/scripts/nice-select2.jscdn.deftform.com/scripts/nice-selec... https://cdn.deftform.com/scripts/nice-select2.js — 200 — 3.3 KiB — 47 ms — h2https://cdn.deftform.com/scripts/iframe-resizer.child.jscdn.deftform.com/scripts/iframe-res... https://cdn.deftform.com/scripts/iframe-resizer.child.js — 200 — 14.1 KiB — 51 ms — h2https://share.deftform.com/build/assets/app-Cs3AlW6n.cssshare.deftform.com/build/assets/app... https://share.deftform.com/build/assets/app-Cs3AlW6n.css — 200 — 35.4 KiB — 55 ms — h2https://share.deftform.com/build/assets/app-CxHcPGqG.cssshare.deftform.com/build/assets/app... https://share.deftform.com/build/assets/app-CxHcPGqG.css — 200 — 3.3 KiB — 25 ms — h2https://share.deftform.com/build/assets/app-DXvwXSXm.jsshare.deftform.com/build/assets/app... https://share.deftform.com/build/assets/app-DXvwXSXm.js — 200 — 135.8 KiB — 79 ms — h2https://df-cdn.com/workspaces/1945c28f-eb2e-400d-bbd3-0a0b51fb5c89/1772634299-logo.pngdf-cdn.com/workspaces/1945c28f-eb2e... https://df-cdn.com/workspaces/1945c28f-eb2e-400d-bbd3-0a0b51fb5c89/1772634299-logo.png — 200 — 6.9 KiB — 135 ms — h2https://share.deftform.com/flux/flux.min.js?id=65fdfb31share.deftform.com/flux/flux.min.js... https://share.deftform.com/flux/flux.min.js?id=65fdfb31 — 200 — 60.6 KiB — 57 ms — h2https://scripts.simpleanalyticscdn.com/latest.jsscripts.simpleanalyticscdn.com/late... https://scripts.simpleanalyticscdn.com/latest.js — 200 — 4.8 KiB — 48 ms — h2https://cdn.deftform.com/styles/phoneinput/intlTelInput.min.csscdn.deftform.com/styles/phoneinput/... https://cdn.deftform.com/styles/phoneinput/intlTelInput.min.css — 200 — 3.2 KiB — 8 ms — h2https://cdn.deftform.com/styles/nice-select2.csscdn.deftform.com/styles/nice-select... https://cdn.deftform.com/styles/nice-select2.css — 200 — 1.9 KiB — 20 ms — h2https://cdn.deftform.com/styles/glightbox.min.csscdn.deftform.com/styles/glightbox.m... https://cdn.deftform.com/styles/glightbox.min.css — 200 — 3.7 KiB — 15 ms — h2https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5Swww.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-TWM2TJ5S — 200 — 118.6 KiB — 55 ms — h2https://region1.google-analytics.com/g/collect?v=2&tid=G-HHL341VPJT&gtm=45je6562v9248621433z89248839776za20gzb9248839776zd9248839776&_p=1778418593099&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1025168359.1778418594&frm=0&pscdl=noapi&rcb=19&sr=412x823&uaa=&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uam=moto%20g%20power%20(2022)&uamb=1&uap=Android&uapv=11.0&uaw=0&ul=en-us&_s=1&tag_exp=0~115938465~115938469~118463262&sid=1778418593&sct=1&seg=0&dl=https%3A%2F%2Fbili.works%2F&dt=Bili%20-%20Clarity%20in%20action&en=page_view&_fv=1&_nsi=1&_ss=1&tfd=667region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-HHL341VPJT&gtm=45je6562v9248621433z89248839776za20gzb9248839776zd9248839776&_p=1778418593099&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1025168359.1778418594&frm=0&pscdl=noapi&rcb=19&sr=412x823&uaa=&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uam=moto%20g%20power%20(2022)&uamb=1&uap=Android&uapv=11.0&uaw=0&ul=en-us&_s=1&tag_exp=0~115938465~115938469~118463262&sid=1778418593&sct=1&seg=0&dl=https%3A%2F%2Fbili.works%2F&dt=Bili%20-%20Clarity%20in%20action&en=page_view&_fv=1&_nsi=1&_ss=1&tfd=667 — 204 — 545 B — 33 ms — h2https://queue.simpleanalyticscdn.com/simple.gif?version=cdn_latest_11&hostname=share.deftform.com&ua=Mozilla%2F5.0%20(X11%3B%20Linux%20x86_64)%20AppleWebKit%2F537.36%20(KHTML%2C%20like%20Gecko)%20HeadlessChrome%2F146.0.0.0%20Safari%2F537.36&https=true&timezone=UTC&page_id=087291c8-1d72-457e-a690-3a7cd4f828a2&session_id=5113e011-d5b2-47ee-8870-66071faec537&sri=false&mobile=false&brands=%5B%7B%22brand%22%3A%22Not-A.Brand%22%2C%22version%22%3A%2224%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22146%22%7D%5D&os_name=Linux&os_version=&path=%2F81e07bb4-0eef-4512-a253-a3af04bed541&viewport_width=284&viewport_height=150&language=en-US&screen_width=800&screen_height=600&unique=true&id=087291c8-1d72-457e-a690-3a7cd4f828a2&type=pageview&referrer=bili.works%2F&time=1778418593754queue.simpleanalyticscdn.com/simple... https://queue.simpleanalyticscdn.com/simple.gif?version=cdn_latest_11&hostname=share.deftform.com&ua=Mozilla%2F5.0%20(X11%3B%20Linux%20x86_64)%20AppleWebKit%2F537.36%20(KHTML%2C%20like%20Gecko)%20HeadlessChrome%2F146.0.0.0%20Safari%2F537.36&https=true&timezone=UTC&page_id=087291c8-1d72-457e-a690-3a7cd4f828a2&session_id=5113e011-d5b2-47ee-8870-66071faec537&sri=false&mobile=false&brands=%5B%7B%22brand%22%3A%22Not-A.Brand%22%2C%22version%22%3A%2224%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22146%22%7D%5D&os_name=Linux&os_version=&path=%2F81e07bb4-0eef-4512-a253-a3af04bed541&viewport_width=284&viewport_height=150&language=en-US&screen_width=800&screen_height=600&unique=true&id=087291c8-1d72-457e-a690-3a7cd4f828a2&type=pageview&referrer=bili.works%2F&time=1778418593754 — 202 — 255 B — 54 ms — h2https://www.googletagmanager.com/gtag/js?id=G-HHL341VPJT&cx=c&gtm=4e6562h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-HHL341VPJT&cx=c&gtm=4e6562h1 — 200 — 156.8 KiB — 37 ms — h2https://bili.works/favicon.ico/favicon.ico https://bili.works/favicon.ico — 404 — 5.4 KiB — 7 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
63% of JavaScript execution is third-party
First-party Third-party 1475ms · 288KB · $20/mo
Unattributable
Other
Costly
Execution 510ms
Transfer 0 KB
Monthly Cost $7/mo
Google Tag Manager
Tag Manager
Costly
Execution 469ms
Transfer 157 KB
Unused 43%
Monthly Cost $6/mo
Google Tag Manager
Tag Manager
Costly
Execution 356ms
Transfer 119 KB
Unused 55%
Monthly Cost $5/mo
cdn.deftform.com
Other
Optional
Execution 140ms
Transfer 12 KB
Monthly Cost $2/mo

These scripts may cost more than they're worth

  • Unattributable adds 510ms and costs ~$7/month
  • Google Tag Manager adds 469ms and costs ~$6/month
  • Google Tag Manager adds 356ms and costs ~$5/month

63% 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 510ms 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

Google Tag Manager takes 469ms 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

Google Tag Manager takes 356ms 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

55% of Google Tag Manager'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

Image Optimization
4 images, 627 KB total, 210 KB wasted
INFO

Image Optimization Audit

Total Images

4

Total Size

627 KB

Oversized

3

Wasted

210 KB

4 missing dimensions 2 missing lazy loading
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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