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.
1.09 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.02 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.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.29 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.
3.02 s
Page Load Progression
FPage Weight BudgetAction2.8 MB transferred, 37 requestsFIX
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
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction37 resources · 2.8 MB · 103 KB savings availableFIX
~102.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 37 resources | 2.8 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization13 images, 0 KB saveableREVIEW
BJS Bundles13 scripts, 103 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://js.monitor.azure.com/scripts/c/ms.analytics-web-4.js | 118 KB | 103 KB (88%) | ✗ | 3rd |
| https://github.blog/wp-content/themes/github-2021/dist/js/site-script.js?m=1776795618g | 29 KB | — | ✓ | 3rd |
| https://github.blog/_static/??-eJx9jdEOwiAMRX9IVlni0Afjt2xAoAzKIiXz860mGp987Tn3FPZN2UrsiWHLPSA1CFFOdUX/Ik2Imskpvs92RQrgsDGkBn+cIbUD/JQ5+uIljBz7osbjqJWNmN23lTFEXurjM0SyuTuZCHs7UZ61oSCJcStXbcxkLqdJn9MTiwNGNQ== | 4 KB | — | ✓ | 3rd |
| https://github.blog/wp-includes/js/dist/i18n.min.js?ver=c26c3dc7bed366793375 | 3 KB | — | ✓ | 3rd |
| https://github.blog/wp-includes/js/dist/url.min.js?m=1774626885g | 4 KB | — | ✓ | 3rd |
| https://github.blog/wp-includes/js/dist/api-fetch.min.js?ver=3a4d9af2b423048b0dee | 3 KB | — | ✓ | 3rd |
| https://ghcc.githubassets.com/ghcc.min.js | 18 KB | — | ✓ | 3rd |
| https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.11.1/highlight.min.js?ver=11.4.0 | 37 KB | — | ✓ | 3rd |
| https://github.blog/wp-content/plugins/page-links-to/dist/new-tab.js?m=1776795618g | 14 KB | — | ✓ | 3rd |
| https://analytics.githubassets.com/v1.1.0/hydro-marketing.min.js?ver=6.9.4 | 4 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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+JS Execution Cost187ms total JS executionPASS
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://github.blog/news-insights/product-news/sunsetting-atom/ | 134ms | 2ms | 1ms | 3rd |
| Unattributable | 53ms | 1ms | 0ms | 3rd |
A+Font Loading3 fonts (1378 KB)PASS
Web fonts
3
1378 KB total
Render-blocking
0
of 3
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 ~669 KB and ~1338 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall37 requests over 1177msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
github.blog github.blog | Other | 134ms | 28 KB | — | $0/mo | Optional |
Unattributable Unattributable | Other | 53ms | 0 KB | — | $0/mo | Optional |
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