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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
73
GRADE
C
FIX
3
REVIEW
3
PASS
6
INFO
2

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

Mobile Desktop
38
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
88
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
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.

2.23 s

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

2.90 s

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

674 ms

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

0.150

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

2.98 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.

6.93 s

Page Load Progression

924 ms
1.8 s
2.8 s
3.7 s
4.6 s
5.5 s
6.5 s
7.4 s
Checks
14
6 PASS 3 REVIEW 3 FIX
F
Page Weight Budget
Action
9.4 MB transferred, 137 requests
FIX
9.4 MB transferred, 137 requests
Critical::
Page weighs 18.4 MB (9.4 MB transferred)
Warning::
Images are 5.9 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 5.9 MB
Warning::
JavaScript is 3.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 3.1 MB
Warning::
137 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 2.0 g CO2 per page load
9.4 MB / 2.4 MB budget
9.4 MB transferred
137 requests
2.0 g CO2 per page load
Images 5.9 MiB 63%
JavaScript 3.1 MiB 33%
CSS 159.5 KiB 2%
Fonts 152.2 KiB 2%
Other 25.0 KiB 0%
HTML 16.8 KiB 0%
Other 15.4 KiB 0%
Other 9.1 KiB 0%
Other 2.1 KiB 0%
Other 666 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

F
JS Execution Cost
Action
4494ms total JS execution
FIX
4494ms total JS execution
Warning::
https://www.jetbrains.com/_assets/common.f1cfd90ed...: 1514ms CPU time
Warning::
Unattributable: 539ms CPU time
Warning::
https://www.jetbrains.com/_assets/index.entry.d4dc...: 504ms CPU time
Warning::
https://resources.jetbrains.com/storage/optly/2661...: 329ms CPU time
Warning::
https://www.jetbrains.com/: 315ms CPU time
Info::
Third-party scripts: 2035ms (45% of total)

Main Thread Breakdown

Script Evaluation 50% Other 22% Parse HTML & CSS 9% Style & Layout 8% Script Parsing & Compilation 7%
ScriptTotalScriptingParse/CompileParty
https://www.jetbrains.com/_assets/common.f1cfd90ed0fb4834ecc2.js1514ms598ms139ms1st
Unattributable539ms23ms0ms3rd
https://www.jetbrains.com/_assets/index.entry.d4dc98d0614badbe65ff.js504ms50ms4ms1st
https://resources.jetbrains.com/storage/optly/26613100737.js329ms298ms19ms3rd
https://www.jetbrains.com/315ms38ms3ms1st
https://www.googletagmanager.com/gtm.js?id=GTM-5P98286ms233ms26ms3rd
https://www.googletagmanager.com/gtag/js?id=G-M8TDRLXFQH&cx=c&gtm=4e6460h1276ms259ms13ms3rd
https://cdn.cookiehub.eu/c2/0acea1b9.js177ms159ms6ms3rd
https://www.jetbrains.com/_assets/default-page.3022c2aa953e916af023.js126ms114ms11ms1st
https://www.googletagmanager.com/gtag/js?id=G-9J976DJZ68&cx=c&gtm=4e6460h1114ms90ms23ms3rd

Showing top 10 of 14 scripts

F
JS Bundles
Action
36 scripts, 1.1 MB unused
FIX
36 scripts, 1.1 MB unused
Warning::
https://www.jetbrains.com/_assets/common.f1cfd90ed...: 535 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-107...: 105 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-NL2...: 73 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://analytics.tiktok.com/i18n/pixel/static/mai...: 63 KB unused (60%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-9J97...: 61 KB unused (35%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.1 MB
1158 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.jetbrains.com/_assets/common.f1cfd90ed0fb4834ecc2.js1347 KB535 KB (40%)✓1st
https://www.googletagmanager.com/gtag/js?id=AW-1071903267&cx=c&gtm=4e6460h1146 KB105 KB (72%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-NL29B334&gtm=4e6460h1167 KB73 KB (44%)✓3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMA.js106 KB63 KB (60%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-9J976DJZ68&cx=c&gtm=4e6460h1174 KB61 KB (35%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-M8TDRLXFQH&cx=c&gtm=4e6460h1143 KB59 KB (41%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-963127096&cx=c&gtm=4e6460h1146 KB54 KB (37%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-5P98203 KB53 KB (26%)✓3rd
https://www.jetbrains.com/_assets/default-page.3022c2aa953e916af023.js84 KB52 KB (62%)✓1st
https://resources.jetbrains.com/storage/optly/26613100737.js130 KB45 KB (34%)✓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
52 images, 0 KB saveable
REVIEW
52 images, 0 KB saveable
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/screenshot... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/part/banner-section/air-... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/logos/customers/logo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/logos/languages/logo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/_assets/common-ui/compon... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/home-page/companies/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.jetbrains.com/img/logos/customers/logo... 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.
52 images 5.9 MB
0 oversized -0 KB
42 legacy format
20 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

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.

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

Green Hosting

No green hosting detected

B
HTTP Caching
max-age=0
REVIEW
max-age=0
Info::
Cache-Control header is set
Got: max-age=0
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=0

DirectiveValueMeaning
max-age0Cache for 0 seconds
A+
Third-Party Impact
19% third-party, 0 ms blocking
PASS
19% third-party, 0 ms blocking
Info::
Third-party code accounts for 19% of page weight (1.8 MiB of 9.4 MiB)
Info::
Third-party blocking time is low (0 ms)
81%
19%
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 (152 KB)
PASS
2 fonts (152 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

152 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 2.2 s LCP 2.9 shttps://resources.jetbrains.com/storage/jetbrains-sans/google-fonts/v1.309/variable/JetBrainsSans[wght].woff2JetBrainsSans[wght].woff2 https://resources.jetbrains.com/storage/jetbrains-sans/google-fonts/v1.309/variable/JetBrainsSans[wght].woff2 — 59.2 KiB — 0 ms — font-display: swaphttps://resources.jetbrains.com/storage/jetbrains-mono/v2.304/webfonts/JetBrainsMono-Bold.woff2JetBrainsMono-Bold.woff2 https://resources.jetbrains.com/storage/jetbrains-mono/v2.304/webfonts/JetBrainsMono-Bold.woff2 — 92.9 KiB — 0 ms — font-display: swap
JetBrainsSans[wght].woff2 woff2 swap
Size 59 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
JetBrainsMono-Bold.woff2 woff2 swap
Size 93 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
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
45% of JavaScript execution is third-party
First-party Third-party 2035ms · 1134KB · €35/mo
Unattributable
Other
Costly
Execution 539ms
Transfer 0 KB
Monthly Cost €9/mo
resources.jetbrains.com
Other
Costly
Execution 329ms
Transfer 130 KB
Unused 34%
Monthly Cost €6/mo
Google Tag Manager
Tag Manager
Costly
Execution 286ms
Transfer 203 KB
Unused 26%
Monthly Cost €5/mo
Google Tag Manager
Tag Manager
Costly
Execution 276ms
Transfer 143 KB
Unused 41%
Monthly Cost €5/mo
cdn.cookiehub.eu
Other
Optional
Execution 177ms
Transfer 38 KB
Monthly Cost €3/mo
Google Tag Manager
Tag Manager
Optional
Execution 114ms
Transfer 174 KB
Unused 35%
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 106ms
Transfer 167 KB
Unused 44%
Monthly Cost €2/mo
Microsoft Clarity
Session Replay
Optional
Execution 87ms
Transfer 26 KB
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 62ms
Transfer 146 KB
Unused 37%
Monthly Cost €1/mo
analytics.tiktok.com
Other
Optional
Execution 59ms
Transfer 106 KB
Unused 60%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • Unattributable adds 539ms and costs ~€9/month
  • resources.jetbrains.com adds 329ms and costs ~€6/month
  • Google Tag Manager adds 286ms and costs ~€5/month
  • Google Tag Manager adds 276ms and costs ~€5/month

45% 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 539ms 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

resources.jetbrains.com takes 329ms 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 286ms 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 276ms 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

60% of analytics.tiktok.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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