Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
7.86 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
45.62 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
3.41 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.004
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
23.48 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.
45.71 s
Page Load Progression
1.2 s
2.4 s 3.6 s 4.8 s 6.0 s 7.1 s
8.3 s
9.5 sFPage Weight BudgetAction7.5 MB transferred, 240 requestsFIX
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.
Source: web.dev
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction9784ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/framework.52e66524.js | 4412ms | 3957ms | 33ms | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~798b6a67.c3afba5f.js | 935ms | 875ms | 58ms | 3rd |
| https://www.douyin.com/ | 880ms | 317ms | 106ms | 3rd |
| Unattributable | 828ms | 23ms | 0ms | 3rd |
| https://lf-security.bytegoofy.com/obj/security-secsdk/runtime_bundler_34.js | 453ms | 272ms | 16ms | 3rd |
| https://p-pc-weboff.byteimg.com/tos-cn-i-9r5gewecjs/bdms_1.0.1.19_fix.js | 379ms | 273ms | 13ms | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/async/81708.18085ed3.js | 280ms | 252ms | 26ms | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~ca98720c.c3c5df70.js | 233ms | 38ms | 46ms | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/libs/pre-build-xgplayer.2408c694.js | 190ms | 136ms | 41ms | 3rd |
| https://lf3-short.ibytedapm.com/slardar/fe/sdk-web/browser.cn.js?bid=douyin_web&globalName=Slardar | 177ms | 165ms | 4ms | 3rd |
Showing top 10 of 22 scripts
FJS BundlesAction131 scripts, 4.4 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/36522.c9062058.js | 262 KB | 254 KB (97%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~798b6a67.c3afba5f.js | 268 KB | 218 KB (82%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/26031.93556802.js | 222 KB | 215 KB (97%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~ca98720c.c3c5df70.js | 157 KB | 129 KB (83%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~8e09d0dc.d528572c.js | 167 KB | 128 KB (78%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/player-8.3b34dad4.js | 130 KB | 104 KB (80%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~33cb90b2.c2629f46.js | 136 KB | 102 KB (76%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/client-entry~1.d35a0183.js | 122 KB | 92 KB (76%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/73481.3896da26.js | 112 KB | 89 KB (81%) | ✓ | 3rd |
| https://lf-douyin-pc-web.douyinstatic.com/obj/douyin-pc-web/ies/douyin_web/async/26094.03a9d867.js | 80 KB | 79 KB (100%) | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction240 resources · 7.5 MB · 4.4 MB savings availableFIX
~4.4 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 240 resources | 7.5 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization11 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font LoadingNo web fonts (system fonts)PASS
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall240 requests over 10721msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 4412ms | 92 KB | 46% | ¥218/mo | Costly |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 935ms | 268 KB | 82% | ¥46/mo | Costly |
www.douyin.com www.douyin.com | Other | 880ms | 111 KB | — | ¥43/mo | Costly |
Unattributable Unattributable | Other | 828ms | 0 KB | — | ¥41/mo | Costly |
lf-security.bytegoofy.com lf-security.bytegoofy.com | Other | 453ms | 44 KB | — | ¥22/mo | Costly |
p-pc-weboff.byteimg.com p-pc-weboff.byteimg.com | Other | 379ms | 64 KB | — | ¥19/mo | Costly |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 280ms | 91 KB | 59% | ¥14/mo | Costly |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 233ms | 157 KB | 83% | ¥12/mo | Costly |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 190ms | 92 KB | 49% | ¥9/mo | Optional |
lf3-short.ibytedapm.com lf3-short.ibytedapm.com | Other | 177ms | 17 KB | — | ¥9/mo | Optional |
lf-c-flwb.bytetos.com lf-c-flwb.bytetos.com | Other | 150ms | 84 KB | 87% | ¥7/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 109ms | 76 KB | 62% | ¥5/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 97ms | 84 KB | 86% | ¥5/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 95ms | 167 KB | 78% | ¥5/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 83ms | 29 KB | 90% | ¥4/mo | Optional |
lf-static.applogcdn.com lf-static.applogcdn.com | Other | 81ms | 52 KB | 59% | ¥4/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 81ms | 198 KB | — | ¥4/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 74ms | 262 KB | 97% | ¥4/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 73ms | 130 KB | 80% | ¥4/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 65ms | 222 KB | 97% | ¥3/mo | Optional |
lf-douyin-pc-web.douyinstatic.com lf-douyin-pc-web.douyinstatic.com | Other | 55ms | 182 KB | — | ¥3/mo | Optional |
lf-rc1.yhgfb-cn-static.com lf-rc1.yhgfb-cn-static.com | Other | 53ms | 29 KB | — | ¥3/mo | Optional |
These scripts may cost more than they're worth
- lf-douyin-pc-web.douyinstatic.com adds 4412ms and costs ~¥218/month
- lf-douyin-pc-web.douyinstatic.com adds 935ms and costs ~¥46/month
- www.douyin.com adds 880ms and costs ~¥43/month
- Unattributable adds 828ms and costs ~¥41/month
- lf-security.bytegoofy.com adds 453ms and costs ~¥22/month
- p-pc-weboff.byteimg.com adds 379ms and costs ~¥19/month
- lf-douyin-pc-web.douyinstatic.com adds 280ms and costs ~¥14/month
- lf-douyin-pc-web.douyinstatic.com adds 233ms and costs ~¥12/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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
lf-douyin-pc-web.douyinstatic.com takes 4412ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
lf-douyin-pc-web.douyinstatic.com takes 935ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
82% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
www.douyin.com takes 880ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Unattributable takes 828ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
lf-security.bytegoofy.com takes 453ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
p-pc-weboff.byteimg.com takes 379ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
lf-douyin-pc-web.douyinstatic.com takes 280ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
59% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
lf-douyin-pc-web.douyinstatic.com takes 233ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
83% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
87% of lf-c-flwb.bytetos.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
62% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
86% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
78% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
90% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
59% of lf-static.applogcdn.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
97% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
80% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
97% of lf-douyin-pc-web.douyinstatic.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev