Performance
· 15 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.
3.57 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
6.23 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
36 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.009
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.56 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.
7.53 s
Page Load Progression
FPage Weight BudgetAction8.1 MB transferred, 159 requestsFIX
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
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.
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.
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
DJS BundlesAction13 scripts, 366 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://userstatic.bjx.com.cn/login/a251010/bjx_login_center/assets/sdk/1.0.3/bjxLogin.js?v=1776891600000 | 422 KB | 336 KB (80%) | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/lib/sensorsdata.min.js?_=1776891618384 | 52 KB | 30 KB (59%) | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/lib/bjx-expose.iife.js?_=1776853942331 | 4 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/comm.js?_=1776853942331 | 3 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/login.js?_=1776853942331 | 6 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/home.js?_=1776853942331 | 2 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/lib/jquery.min.js?_=1776853942331 | 32 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/reportdata.js?_=1776853942331 | 1 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/site_map.js?_=1776853942331 | 4 KB | — | ✓ | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/eap.js?_=1776891618382 | 1 KB | — | ✓ | 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
DPage Weight InventoryAction159 resources · 8.1 MB · 366 KB savings availableFIX
~366.0 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 159 resources | 8.1 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction109 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
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
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
CJS Execution CostAction1486ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.bjx.com.cn/ | 783ms | 3ms | 0ms | 3rd |
| Unattributable | 362ms | 1ms | 0ms | 3rd |
| https://userstatic.bjx.com.cn/login/a251010/bjx_login_center/assets/sdk/1.0.3/bjxLogin.js?v=1776891600000 | 133ms | 85ms | 46ms | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/lib/jquery.min.js?_=1776853942331 | 74ms | 46ms | 3ms | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/lib/bjx-expose.iife.js?_=1776853942331 | 71ms | 59ms | 0ms | 3rd |
| https://newsstatic.bjx.com.cn/public/a210726/bjx_mt_00/js/home.js?_=1776853942331 | 64ms | 53ms | 0ms | 3rd |
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 Loading1 fonts (8 KB)PASS
Web fonts
1
8 KB total
Render-blocking
0
of 1
Dominant font-display
swap
Most common across fonts
Font loading timeline
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 CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall159 requests over 10677msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.bjx.com.cn www.bjx.com.cn | Other | 783ms | 22 KB | — | ¥39/mo | Costly |
Unattributable Unattributable | Other | 362ms | 0 KB | — | ¥18/mo | Costly |
userstatic.bjx.com.cn userstatic.bjx.com.cn | Other | 133ms | 422 KB | 80% | ¥7/mo | Optional |
newsstatic.bjx.com.cn newsstatic.bjx.com.cn | Other | 74ms | 32 KB | — | ¥4/mo | Optional |
newsstatic.bjx.com.cn newsstatic.bjx.com.cn | Other | 71ms | 4 KB | — | ¥4/mo | Optional |
newsstatic.bjx.com.cn newsstatic.bjx.com.cn | Other | 64ms | 2 KB | — | ¥3/mo | Optional |
These scripts may cost more than they're worth
- www.bjx.com.cn adds 783ms and costs ~¥39/month
- Unattributable adds 362ms and costs ~¥18/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
www.bjx.com.cn takes 783ms 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 362ms 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
80% of userstatic.bjx.com.cn'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