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.
7.56 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
22.51 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.67 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.205
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
14.98 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.
35.98 s
Page Load Progression
375 ms
750 ms 1.1 s 1.5 s 1.9 s 2.2 s
2.6 s 3.0 sFPage Weight BudgetAction6.3 MB transferred, 205 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
Subset fonts to include only used characters, or switch to system font stacks.
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.
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 CostAction10396ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.koreatimes.co.kr/_next/static/chunks/5807-44986e848a19e569.js | 2189ms | 1770ms | 20ms | 3rd |
| https://www.koreatimes.co.kr/ | 1775ms | 82ms | 56ms | 3rd |
| Unattributable | 1695ms | 205ms | 0ms | 3rd |
| https://cdn.taboola.com/libtrc/koreatimes-responsive/loader.js | 904ms | 592ms | 107ms | 3rd |
| https://www.koreatimes.co.kr/_next/static/chunks/a27014fc-4be8f0bae1a53d3c.js | 862ms | 715ms | 24ms | 3rd |
| https://3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.com/3b5f55dbe791/e90e0e24c440/0c34be11ca52/challenge.js | 724ms | 520ms | 124ms | 3rd |
| https://www.koreatimes.co.kr/_next/static/chunks/runtime-c0ed6c5f339fb602.js | 435ms | 433ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-W0W8TFL0RB | 388ms | 322ms | 57ms | 3rd |
| https://scripts.clarity.ms/0.8.59/clarity.js | 233ms | 191ms | 8ms | 3rd |
| https://sdk.mrf.io/statics/marfeel-sdk.js?id=9291 | 216ms | 206ms | 1ms | 3rd |
Showing top 10 of 17 scripts
FJS BundlesAction47 scripts, 1.1 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.com/3b5f55dbe791/e90e0e24c440/0c34be11ca52/challenge.js | 501 KB | 280 KB (56%) | ✓ | 3rd |
| https://www.koreatimes.co.kr/_next/static/chunks/2752-e71655caefa64767.js | 357 KB | 245 KB (69%) | ✓ | 3rd |
| https://cdn.taboola.com/libtrc/koreatimes-responsive/loader.js | 318 KB | 173 KB (55%) | ✓ | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604100101/pubads_impl.js | 186 KB | 142 KB (76%) | ✓ | 3rd |
| https://www.koreatimes.co.kr/_next/static/chunks/2102-2e1b9afa76656ad7.js | 90 KB | 81 KB (90%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-KBMFRS3H | 120 KB | 65 KB (54%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-W0W8TFL0RB | 163 KB | 60 KB (37%) | ✓ | 3rd |
| https://www.koreatimes.co.kr/_next/static/chunks/4550-ce78a704cd833264.js | 54 KB | 28 KB (53%) | ✓ | 3rd |
| https://sdk.mrf.io/statics/marfeel-sdk.js?id=9291 | 58 KB | 25 KB (44%) | ✓ | 3rd |
| https://www.koreatimes.co.kr/_next/static/chunks/1265-2c992cc82091cc55.js | 33 KB | 23 KB (71%) | ✓ | 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 InventoryAction205 resources · 6.3 MB · 1.1 MB savings availableFIX
~1.1 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 205 resources | 6.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization87 images, 0 KB saveableREVIEW
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 Loading4 fonts (911 KB)PASS
Web fonts
4
911 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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)
Fixing the unchecked items could save ~435 KB and ~870 ms
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 Waterfall205 requests over 36902msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 2189ms | 32 KB | — | ₩8643/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 1775ms | 114 KB | — | ₩7008/mo | Costly |
Unattributable Unattributable | Other | 1695ms | 0 KB | — | ₩6690/mo | Costly |
cdn.taboola.com cdn.taboola.com | Other | 904ms | 318 KB | 55% | ₩3570/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 862ms | 53 KB | — | ₩3404/mo | Costly |
3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.com 3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.com | Other | 724ms | 501 KB | 56% | ₩2858/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 435ms | 4 KB | — | ₩1719/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 388ms | 163 KB | 37% | ₩1531/mo | Costly |
Microsoft Clarity scripts.clarity.ms | Session Replay | 233ms | 26 KB | — | ₩921/mo | Costly |
sdk.mrf.io sdk.mrf.io | Other | 216ms | 58 KB | 44% | ₩852/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 204ms | 186 KB | 76% | ₩804/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 200ms | 357 KB | 69% | ₩788/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 174ms | 120 KB | 54% | ₩688/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 141ms | 12 KB | — | ₩558/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 104ms | 34 KB | — | ₩409/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 79ms | 33 KB | 71% | ₩313/mo | Costly |
www.koreatimes.co.kr www.koreatimes.co.kr | Other | 72ms | 54 KB | 53% | ₩286/mo | Costly |
These scripts may cost more than they're worth
- www.koreatimes.co.kr adds 2189ms and costs ~₩8643/month
- www.koreatimes.co.kr adds 1775ms and costs ~₩7008/month
- Unattributable adds 1695ms and costs ~₩6690/month
- cdn.taboola.com adds 904ms and costs ~₩3570/month
- www.koreatimes.co.kr adds 862ms and costs ~₩3404/month
- 3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.com adds 724ms and costs ~₩2858/month
- www.koreatimes.co.kr adds 435ms and costs ~₩1719/month
- Google Tag Manager adds 388ms and costs ~₩1531/month
- Microsoft Clarity adds 233ms and costs ~₩921/month
- sdk.mrf.io adds 216ms and costs ~₩852/month
- securepubads.g.doubleclick.net adds 204ms and costs ~₩804/month
- www.koreatimes.co.kr adds 200ms and costs ~₩788/month
- Google Tag Manager adds 174ms and costs ~₩688/month
- www.koreatimes.co.kr adds 141ms and costs ~₩558/month
- securepubads.g.doubleclick.net adds 104ms and costs ~₩409/month
- www.koreatimes.co.kr adds 79ms and costs ~₩313/month
- www.koreatimes.co.kr adds 72ms and costs ~₩286/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.koreatimes.co.kr takes 2189ms 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
www.koreatimes.co.kr takes 1775ms 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 1695ms 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
cdn.taboola.com takes 904ms 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
55% of cdn.taboola.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.koreatimes.co.kr takes 862ms 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
3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.com takes 724ms 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
56% of 3b5f55dbe791.7fcd4902.eu-west-3.token.awswaf.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.koreatimes.co.kr takes 435ms 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
Google Tag Manager takes 388ms 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
Microsoft Clarity 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
sdk.mrf.io takes 216ms 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
securepubads.g.doubleclick.net takes 204ms 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
76% of securepubads.g.doubleclick.net'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.koreatimes.co.kr takes 200ms 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
69% of www.koreatimes.co.kr'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
Google Tag Manager takes 174ms 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
54% of Google Tag Manager'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.koreatimes.co.kr takes 141ms 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
securepubads.g.doubleclick.net takes 104ms 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
www.koreatimes.co.kr takes 79ms 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
71% of www.koreatimes.co.kr'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.koreatimes.co.kr takes 72ms 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
53% of www.koreatimes.co.kr'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