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https://www.yelp.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
78
GRADE
C
FIX
3
REVIEW
4
PASS
5
INFO
2

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

Mobile Desktop
56
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
99
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.
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.

2.17 s

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

2.67 s

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

258 ms

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

0.159

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

2.25 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.

4.28 s

Page Load Progression

518 ms
1.0 s
1.6 s
2.1 s
2.6 s
3.1 s
3.6 s
4.1 s
Checks
14
5 PASS 4 REVIEW 3 FIX
D
Page Weight Budget
Action
2.4 MB transferred, 125 requests
FIX
2.4 MB transferred, 125 requests
Warning::
Page weighs 6.1 MB (2.4 MB transferred)
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::
125 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.51 g CO2 per page load
2.4 MB / 2.4 MB budget
2.4 MB transferred
125 requests
0.51 g CO2 per page load
JavaScript 1.2 MiB 50%
Images 882.7 KiB 35%
Fonts 149.8 KiB 6%
Other 104.2 KiB 4%
HTML 64.3 KiB 3%
CSS 38.4 KiB 2%
Other 5.1 KiB 0%
Other 2.6 KiB 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

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (2.4 MiB of 2.4 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Bundles
Action
72 scripts, 502 KB unused
FIX
72 scripts, 502 KB unused
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/mod...: 168 KB unused (70%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/mod...: 156 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/mod...: 65 KB unused (87%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/mod...: 38 KB unused (89%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/mod...: 35 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 502 KB
502 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-137874594457bb19444d508ffc1b8360f6254e3a.yji-62489aa171f876f5.mjs244 KB168 KB (70%)✓3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-04db01acf929d247523f4c52ac2c8215935f52b9.yji-30d1c513c6e158ab.mjs304 KB156 KB (51%)✓3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_lib-lottie-web-5.13.0.yji-ff94554bd2c9ef61.mjs75 KB65 KB (87%)✓3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-38da6e3779eb5a15c916aad6406379e2ece7b418.yji-b9d8084566b67fef.mjs43 KB38 KB (89%)✓3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_gondola-homepage.yji-efb15c5b3edad00f.mjs72 KB35 KB (49%)✓3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-b2f0353fe714602062eef7e1466f94411bd11e09.yji-6cb2cb9fddec323c.mjs23 KB20 KB (88%)✓3rd
https://s3-media0.fl.yelpcdn.com/assets/srv0/cdn_assets/d92e3267df3b/assets/vendor/react-dom-client/19.2.4/esm/react-dom-client.production.mjs60 KB20 KB (34%)✗3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-8f8c91a89c223ee1e68cad5825e7f2c2e0cdb891.yji-ad4e3dfc521d2a69.mjs2 KB—✓3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-12adb465f985aba706d9f47be7a6344bc0bb4875.yji-f1c3d34f9206fda4.mjs12 KB—✓3rd
https://js.datadome.co/tags.js43 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

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
35 images, 0 KB saveable
REVIEW
35 images, 0 KB saveable
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/40x... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s3-media0.fl.yelpcdn.com/assets/srv0/yelp_... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
35 images 883 KB
0 oversized -0 KB
35 legacy format
8 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

C
JS Execution Cost
Action
1858ms total JS execution
REVIEW
1858ms total JS execution
Warning::
Unattributable: 689ms CPU time
Warning::
https://s3-media0.fl.yelpcdn.com/assets/public/mod...: 461ms CPU time
Warning::
https://www.yelp.fr/paris: 379ms CPU time
Info::
https://js.datadome.co/tags.js: 175ms CPU time
Info::
https://s3-media0.fl.yelpcdn.com/assets/srv0/cdn_a...: 154ms CPU time
Warning::
Third-party scripts: 1858ms (100% of total)

Main Thread Breakdown

Script Evaluation 53% Other 30% Style & Layout 7% Rendering 4%
ScriptTotalScriptingParse/CompileParty
Unattributable689ms285ms0ms3rd
https://s3-media0.fl.yelpcdn.com/assets/public/module_yelp-frontend_shared-04db01acf929d247523f4c52ac2c8215935f52b9.yji-30d1c513c6e158ab.mjs461ms423ms4ms3rd
https://www.yelp.fr/paris379ms8ms17ms3rd
https://js.datadome.co/tags.js175ms158ms2ms3rd
https://s3-media0.fl.yelpcdn.com/assets/srv0/cdn_assets/d92e3267df3b/assets/vendor/react-dom-client/19.2.4/esm/react-dom-client.production.mjs154ms130ms0ms3rd
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
no-cache
REVIEW
no-cache
Info::
Cache-Control header is set
Got: no-cache
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

no-cache

DirectiveValueMeaning
no-cache—Cache but always revalidate first
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 (150 KB)
PASS
5 fonts (150 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

150 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 1.5 s 2.0 s 2.5 s FCP 2.2 s LCP 2.7 shttps://s3-media0.fl.yelpcdn.com/assets/public/open-sans-regular.yji-0ffa35321c9a4edc.woff2open-sans-regular.yji-0... https://s3-media0.fl.yelpcdn.com/assets/public/open-sans-regular.yji-0ffa35321c9a4edc.woff2 — 43.4 KiB — 0 ms — font-display: swaphttps://s3-media0.fl.yelpcdn.com/assets/public/open-sans-semibold.yji-7a0d1b8cfe27b45a.woff2open-sans-semibold.yji-... https://s3-media0.fl.yelpcdn.com/assets/public/open-sans-semibold.yji-7a0d1b8cfe27b45a.woff2 — 45.3 KiB — 0 ms — font-display: swaphttps://s3-media0.fl.yelpcdn.com/assets/public/open-sans-bold.yji-5d14ee0b48af7d8b.woff2open-sans-bold.yji-5d14... https://s3-media0.fl.yelpcdn.com/assets/public/open-sans-bold.yji-5d14ee0b48af7d8b.woff2 — 45.3 KiB — 0 ms — font-display: swaphttps://s3-media0.fl.yelpcdn.com/assets/public/poppins-bold.yji-0319f02e4fd3c5a4.woff2poppins-bold.yji-0319f0... https://s3-media0.fl.yelpcdn.com/assets/public/poppins-bold.yji-0319f02e4fd3c5a4.woff2 — 7.8 KiB — 0 ms — font-display: swaphttps://s3-media0.fl.yelpcdn.com/assets/public/poppins-medium.yji-6a722094612266f8.woff2poppins-medium.yji-6a72... https://s3-media0.fl.yelpcdn.com/assets/public/poppins-medium.yji-6a722094612266f8.woff2 — 8.0 KiB — 0 ms — font-display: swap
open-sans-regular.yji-0... woff2 swap
Size 43 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
open-sans-semibold.yji-... woff2 swap
Size 45 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
open-sans-bold.yji-5d14... woff2 swap
Size 45 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
poppins-bold.yji-0319f0... woff2 swap
Size 8 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
poppins-medium.yji-6a72... woff2 swap
Size 8 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
Network Waterfall
125 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
100% of JavaScript execution is third-party
First-party Third-party 1858ms · 471KB · $25/mo
Unattributable
Other
Costly
Execution 689ms
Transfer 0 KB
Monthly Cost $9/mo
s3-media0.fl.yelpcdn.com
Other
Costly
Execution 461ms
Transfer 304 KB
Unused 51%
Monthly Cost $6/mo
www.yelp.fr
Other
Costly
Execution 379ms
Transfer 64 KB
Monthly Cost $5/mo
js.datadome.co
Other
Optional
Execution 175ms
Transfer 43 KB
Monthly Cost $2/mo
s3-media0.fl.yelpcdn.com
Other
Optional
Execution 154ms
Transfer 60 KB
Unused 34%
Monthly Cost $2/mo

These scripts may cost more than they're worth

  • Unattributable adds 689ms and costs ~$9/month
  • s3-media0.fl.yelpcdn.com adds 461ms and costs ~$6/month
  • www.yelp.fr adds 379ms and costs ~$5/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.

Learn more ▾

Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.

Source: web.dev

Unattributable takes 689ms 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

s3-media0.fl.yelpcdn.com takes 461ms 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

51% of s3-media0.fl.yelpcdn.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

www.yelp.fr takes 379ms 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

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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