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.
1.45 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.22 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
0 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.002
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.37 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.
2.22 s
Page Load Progression
FPage Weight BudgetAction11.4 MB transferred, 94 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
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
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
FJS BundlesAction27 scripts, 582 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=AW-10841925644&cx=c>m=4e64k0 | 178 KB | 115 KB (65%) | ✓ | 3rd |
| https://isweb.co.kr/file/plugin/froala/js/froala_editor.pkgd.min.js | 129 KB | 112 KB (87%) | ✓ | 1st |
| https://isweb.co.kr/file/plugin/jquery.ui/jquery-ui.js | 114 KB | 99 KB (87%) | ✗ | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-YSW21L2669 | 177 KB | 65 KB (37%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-T4QV2F8C | 124 KB | 65 KB (53%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-10841925644 | 178 KB | 60 KB (34%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 35 KB (36%) | ✓ | 3rd |
| https://isweb.co.kr/file/renew/js/swiper.min.js | 36 KB | 31 KB (89%) | ✗ | 1st |
| https://ssl.pstatic.net/melona/libs/gfp-nac-module/synchronizer.js | 18 KB | — | ✓ | 3rd |
| https://cdn.onetag.co.kr/0/tcs.js?eid=1h823ex6u2ypg1h823ex6u | 12 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
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
DPage Weight InventoryAction94 resources · 11.4 MB · 582 KB savings availableFIX
~581.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 94 resources | 11.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction24 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
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
BJS Execution Cost609ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 180ms | 2ms | 0ms | 3rd |
| https://isweb.co.kr/ | 161ms | 14ms | 1ms | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-YSW21L2669 | 88ms | 65ms | 22ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-10841925644 | 68ms | 58ms | 9ms | 3rd |
| https://isweb.co.kr/cdn-cgi/challenge-platform/scripts/jsd/main.js | 61ms | 59ms | 1ms | 1st |
| https://isweb.co.kr/file/plugin/jquery.ui/jquery-ui.js | 51ms | 9ms | 9ms | 1st |
A+Third-Party Impact10% third-party, 0 ms blockingPASS
A+Text CompressionAll text resources are compressedPASS
A+Font Loading4 fonts (4571 KB)PASS
Web fonts
4
4571 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- 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 ~3657 KB and ~7314 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall94 requests over 5239msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 180ms | 0 KB | — | ₩709/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 88ms | 177 KB | 37% | ₩347/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 68ms | 178 KB | 34% | ₩267/mo | Costly |
These scripts may cost more than they're worth
- Unattributable adds 180ms and costs ~₩709/month
- Google Tag Manager adds 88ms and costs ~₩347/month
- Google Tag Manager adds 68ms and costs ~₩267/month
55% of JavaScript execution time comes from third-party scripts.
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 180ms 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 88ms 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 68ms 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