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.
1.22 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.88 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
271 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.
1.40 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.
3.62 s
Page Load Progression
BThird-Party Impact42% third-party, 0 ms blockingREVIEW
CJS Execution CostAction1039ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-LLFSDKZXET | 315ms | 236ms | 57ms | 3rd |
| Unattributable | 195ms | 7ms | 0ms | 3rd |
| https://rentry.co/ | 172ms | 7ms | 2ms | 1st |
| https://rentry.co/static/js/jquery.min.js?vsson=40 | 170ms | 135ms | 18ms | 1st |
| https://rentry.co/static/js/custom.min.js?vsson=40 | 122ms | 55ms | 1ms | 1st |
| https://rentry.co/static/codemirror/lib/codemirror.min.js?vsson=40 | 66ms | 36ms | 30ms | 1st |
BJS Bundles10 scripts, 109 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-LLFSDKZXET | 148 KB | 62 KB (42%) | ✓ | 3rd |
| https://rentry.co/static/codemirror/lib/codemirror.min.js?vsson=40 | 70 KB | 47 KB (67%) | ✓ | 1st |
| https://rentry.co/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js | 1 KB | — | ✓ | 1st |
| https://rentry.co/static/js/jquery.min.js?vsson=40 | 34 KB | — | ✓ | 1st |
| https://rentry.co/static/js/bootstrap.min.js?vsson=40 | 16 KB | — | ✓ | 1st |
| https://rentry.co/static/markdownx/markdownx.min.js?vsson=40 | 2 KB | — | ✓ | 1st |
| https://rentry.co/static/codemirror/addon/mode/overlay.min.js?vsson=40 | 1 KB | — | ✓ | 1st |
| https://rentry.co/static/codemirror/mode/markdown/markdown.min.js?vsson=40 | 5 KB | — | ✓ | 1st |
| https://rentry.co/static/codemirror/mode/gfm/gfm.min.js?vsson=40 | 1 KB | — | ✓ | 1st |
| https://rentry.co/static/js/custom.min.js?vsson=40 | 2 KB | — | ✓ | 1st |
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
BHTTP CachingVaryREVIEW
Vary
| Directive | Value | Meaning |
|---|---|---|
| vary | — |
A+Page Weight Budget356 KB transferred, 18 requestsPASS
A+Text CompressionAll text resources are compressedPASS
A+Image Optimization3 images, 0 KB saveablePASS
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
APage Weight Inventory18 resources · 356 KB · 109 KB savings availablePASS
~108.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 18 resources | 355.8 KiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall18 requests over 513msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Google Tag Manager www.googletagmanager.com | Tag Manager | 315ms | 148 KB | 42% | $4/mo | Costly |
Unattributable Unattributable | Other | 195ms | 0 KB | — | $3/mo | Optional |
These scripts may cost more than they're worth
- Google Tag Manager adds 315ms and costs ~$4/month
49% 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
Google Tag Manager takes 315ms 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