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https://www.tiktok.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
71
GRADE
C
FIX
5
REVIEW
2
PASS
5
INFO
2

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

Mobile Desktop
27
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
71
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
77
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.

2.03 s

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

8.80 s

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

615 ms

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

0.164

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

4.21 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.

9.14 s

Page Load Progression

1.2 s
2.5 s
3.7 s
5.0 s
6.2 s
7.4 s
8.7 s
9.9 s
Checks
14
5 PASS 2 REVIEW 5 FIX
F
Page Weight Budget
Action
22.6 MB transferred, 374 requests
FIX
22.6 MB transferred, 374 requests
Critical::
Page weighs 37.0 MB (22.6 MB transferred)
Warning::
Images are 5.8 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 5.8 MB
Warning::
JavaScript is 4.9 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 4.9 MB
Info::
Fonts are 286 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 286 KB
Warning::
374 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 4.7 g CO2 per page load
22.6 MB / 2.4 MB budget
22.6 MB transferred
374 requests
4.7 g CO2 per page load
Other 11.1 MiB 49%
Images 5.8 MiB 26%
JavaScript 4.9 MiB 22%
Fonts 285.7 KiB 1%
Other 194.4 KiB 1%
Other 96.8 KiB 0%
HTML 77.0 KiB 0%
Other 63.5 KiB 0%
CSS 46.2 KiB 0%
Other 1.2 KiB 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

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

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
99% third-party, 0 ms blocking
FIX
99% third-party, 0 ms blocking
Warning::
Third-party code accounts for 99% of page weight (22.3 MiB of 22.6 MiB)
Info::
Third-party blocking time is low (0 ms)
99%
First-party Third-party
F
JS Execution Cost
Action
5470ms total JS execution
FIX
5470ms total JS execution
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 1741ms CPU time
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 1287ms CPU time
Warning::
Unattributable: 712ms CPU time
Warning::
https://www.tiktok.com/explore: 481ms CPU time
Info::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 231ms CPU time
Warning::
Third-party scripts: 4989ms (91% of total)

Main Thread Breakdown

Script Evaluation 64% Other 16% Script Parsing & Compilation 8% Style & Layout 7% Garbage Collection 3%
ScriptTotalScriptingParse/CompileParty
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/npm-react.c4ee0173.js1741ms1572ms8ms3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/webmssdk/1.0.0.347/webmssdk.js1287ms993ms5ms3rd
Unattributable712ms109ms0ms3rd
https://www.tiktok.com/explore481ms8ms0ms1st
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok_privacy_protection_framework/loader/1.0.0.933/index.js231ms185ms4ms3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/biz.shared.init.77a26646.js175ms169ms5ms3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/64887.aa44c2fe.js110ms86ms22ms3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/slardar/fe/sdk-web/browser.euttp.js?bid=tiktok_webapp&globalName=SlardarClient100ms29ms2ms3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/30846.1e766293.js98ms95ms2ms3rd
https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/secsdk/secsdk-lastest.umd.js97ms92ms4ms3rd

Showing top 10 of 16 scripts

F
JS Bundles
Action
188 scripts, 1.7 MB unused
FIX
188 scripts, 1.7 MB unused
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 156 KB unused (50%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 151 KB unused (70%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 97 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 90 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://sf16-website-login.neutral.tiktokcdn-eu.co...: 67 KB unused (53%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.7 MB
1754 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/login-modal.08142072.js310 KB156 KB (50%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/10540.6097c794.js218 KB151 KB (70%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/pns/tiktok-cookie-banner/1.0.0.285/default.eu-ttp.esm.js178 KB97 KB (55%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/64887.aa44c2fe.js143 KB90 KB (63%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/99593.685f1d7c.js127 KB67 KB (53%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/instance.9165f764.js81 KB66 KB (83%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/npm-lottie.29812993.js73 KB63 KB (87%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/cache.tux.0c5e850c.js98 KB62 KB (64%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/78533.2e7df324.js81 KB61 KB (75%)✓3rd
https://sf16-website-login.neutral.tiktokcdn-eu.com/obj/tiktok_web_login_static_eu/tiktok/webapp/main/react-v18/webapp-desktop/static/js/async/57651.47837b66.js91 KB59 KB (66%)✓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

D
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: max-age=0, no-cache, no-store
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=0, no-cache, no-store

DirectiveValueMeaning
max-age0Cache for 0 seconds
no-cache—Cache but always revalidate first
no-store—Never cache this response
B
Image Optimization
62 images, 0 KB saveable
REVIEW
62 images, 0 KB saveable
Info::
All images are well-optimized
62 images 5.8 MB
0 oversized -0 KB
59 legacy format
0 missing dimensions CLS risk
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

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
8 fonts (286 KB)
PASS
8 fonts (286 KB)
Info::
8 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

8

286 KB total

Render-blocking

0

of 8

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 8.0 s 9.0 s FCP 2.0 s LCP 8.8 shttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Semibold.woff2?_default_font=1&v=2TikTokFont-Semibold.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Semibold.woff2?_default_font=1&v=2 — 56.7 KiB — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Regular.woff2?_default_font=1&v=2TikTokFont-Regular.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Regular.woff2?_default_font=1&v=2 — 56.1 KiB — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Bold.woff2?_default_font=1&v=2TikTokFont-Bold.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Bold.woff2?_default_font=1&v=2 — 57.8 KiB — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokDisplayFont-Bold.woff2?_default_font=1&v=2TikTokDisplayFont-Bold.... https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokDisplayFont-Bold.woff2?_default_font=1&v=2 — 58.4 KiB — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Regular.woff2?_default_font=1&v=2TikTokFont-Regular.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Regular.woff2?_default_font=1&v=2 — 0 B — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-SEMIBOLD.woff2?_default_font=1&v=2TikTokFont-SEMIBOLD.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-SEMIBOLD.woff2?_default_font=1&v=2 — 56.6 KiB — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Bold.woff2?_default_font=1&v=2TikTokFont-Bold.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Bold.woff2?_default_font=1&v=2 — 0 B — 0 ms — font-display: swaphttps://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Semibold.woff2?_default_font=1&v=2TikTokFont-Semibold.woff2 https://sf16-website-login.neutral.ttwstatic.com/obj/tiktok_web_login_static/tiktok_fonts/TikTokFont-Semibold.woff2?_default_font=1&v=2 — 0 B — 0 ms — font-display: swap
TikTokFont-Semibold.woff2 woff2 swap
Size 57 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokFont-Regular.woff2 woff2 swap
Size 56 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokFont-Bold.woff2 woff2 swap
Size 58 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokDisplayFont-Bold.... woff2 swap
Size 58 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokFont-Regular.woff2 woff2 swap
Size 0 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokFont-SEMIBOLD.woff2 woff2 swap
Size 57 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokFont-Bold.woff2 woff2 swap
Size 0 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
TikTokFont-Semibold.woff2 woff2 swap
Size 0 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
374 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
91% of JavaScript execution is third-party
First-party Third-party 4989ms · 1257KB · €54/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Costly
Execution 1741ms
Transfer 67 KB
Unused 45%
Monthly Cost €19/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Costly
Execution 1287ms
Transfer 94 KB
Monthly Cost €14/mo
Unattributable
Other
Costly
Execution 712ms
Transfer 0 KB
Monthly Cost €8/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Costly
Execution 231ms
Transfer 37 KB
Monthly Cost €3/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 175ms
Transfer 49 KB
Unused 42%
Monthly Cost €2/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 110ms
Transfer 143 KB
Unused 63%
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 100ms
Transfer 16 KB
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 98ms
Transfer 37 KB
Unused 74%
Monthly Cost €1/mo
sf16-website-login.neutral.ttwstatic.com
Other
Optional
Execution 97ms
Transfer 42 KB
Unused 50%
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 93ms
Transfer 8 KB
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 93ms
Transfer 178 KB
Unused 55%
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 83ms
Transfer 147 KB
Unused 16%
Monthly Cost €1/mo
sf16-website-login.neutral.ttwstatic.com
Other
Optional
Execution 61ms
Transfer 92 KB
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 55ms
Transfer 127 KB
Unused 53%
Monthly Cost €1/mo
sf16-website-login.neutral.tiktokcdn-eu.com
Other
Optional
Execution 54ms
Transfer 218 KB
Unused 70%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • sf16-website-login.neutral.tiktokcdn-eu.com adds 1741ms and costs ~€19/month
  • sf16-website-login.neutral.tiktokcdn-eu.com adds 1287ms and costs ~€14/month
  • Unattributable adds 712ms and costs ~€8/month
  • sf16-website-login.neutral.tiktokcdn-eu.com adds 231ms and costs ~€3/month

91% 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

sf16-website-login.neutral.tiktokcdn-eu.com takes 1741ms 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

sf16-website-login.neutral.tiktokcdn-eu.com takes 1287ms 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

Unattributable takes 712ms 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

sf16-website-login.neutral.tiktokcdn-eu.com takes 231ms 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

63% of sf16-website-login.neutral.tiktokcdn-eu.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

74% of sf16-website-login.neutral.tiktokcdn-eu.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

55% of sf16-website-login.neutral.tiktokcdn-eu.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

53% of sf16-website-login.neutral.tiktokcdn-eu.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

70% of sf16-website-login.neutral.tiktokcdn-eu.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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