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https://Pennycalc.com

Performance

· 21 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
1
REVIEW
6
PASS
12
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
100
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
91
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

467 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

531 ms

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.

527 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

531 ms

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
21
12 PASS 6 REVIEW 1 FIX
D
Third-Party Impact
Action
93% third-party, 0 ms blocking
FIX
93% third-party, 0 ms blocking
Warning::
Third-party code accounts for 93% of page weight (473.0 KiB of 509.0 KiB)
Info::
Third-party blocking time is low (0 ms)
93%
First-party Third-party
C
JS Bundles
Action
7 scripts, 279 KB unused
REVIEW
7 scripts, 279 KB unused
Warning::
https://pagead2.googlesyndication.com/pagead/manag...: 148 KB unused (84%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-8DBK...: 66 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://fundingchoicesmessages.google.com/i/ca-pub...: 36 KB unused (53%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://pagead2.googlesyndication.com/pagead/js/ad...: 29 KB unused (53%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 279 KB
279 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://pagead2.googlesyndication.com/pagead/managed/js/adsense/m202605040101/show_ads_impl_fy2021.js177 KB148 KB (84%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-8DBKHCRCKZ158 KB66 KB (42%)✓3rd
https://fundingchoicesmessages.google.com/i/ca-pub-7877367868278158?href=https%3A%2F%2Fpennycalc.com&ers=270 KB36 KB (53%)✓3rd
https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-787736786827815854 KB29 KB (53%)✓3rd
https://pennycalc.com/scripts/tween-numbers.js2 KB—✓1st
https://static.cloudflareinsights.com/beacon.min.js11 KB—✓3rd
https://fundingchoicesmessages.google.com/f/AGSKWxV8ebbDZELfXCJaW2o7QDZ583s2BjHsMl1W12pI3ovIRqiRUyvp8wpBtHjPsRF7fmL0WyBJiTHCKhulFP7MPPVnz8EHgyA0T-BdeX88TnwqkXViBQ0lxm6QTwrmuvMpdbJ2D9LIGA==?fccs=W251bGwsbnVsbCxudWxsLG51bGwsbnVsbCxudWxsLFsxNzc4NDEyNjk4LDg3NTAwMDAwMF0sbnVsbCxudWxsLG51bGwsW251bGwsWzddXSwiaHR0cHM6Ly9wZW5ueWNhbGMuY29tLyIsbnVsbCxbWzgsIlJpYXFiblNJNWVjIl0sWzksImVuLVVTIl0sWzE4LCJbW1tudWxsLDUwOF1dXSJdLFszNSwiMTc3ODQxMjY5OCJdLFsxOSwiMSJdLFsxNywiWzBdIl0sWzI0LCIiXSxbMjksInRydWUiXV1d2 KB—✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
No Server-Timing header found
Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.
B
Page Weight Inventory
18 resources · 509 KB · 279 KB savings available
REVIEW
18 resources · 509 KB · 279 KB savings available
Info::
Within 1MB page-weight target
Got: 509 KB
Info::
~279 KB of savings available
Warning::
13 third-party resources (93% of weight)
18 resources · 509.0 KiB · 13 third-party Within 1MB page-weight target
JavaScript 93% · 474.4 KiB
CSS 4% · 21.4 KiB
Document 2% · 11.9 KiB
Image 0% · 718 B
Other 0% · 582 B

~279.0 KiB of savings available

Remove unused JavaScript: 279.0 KiB
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
public, max-age=0, must-revalidate
REVIEW
public, max-age=0, must-revalidate
Info::
Cache-Control header is set
Got: public, max-age=0, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public, max-age=0, must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A+
Page Weight Budget
509 KB transferred, 18 requests
PASS
509 KB transferred, 18 requests
Info::
Page weighs 1.6 MB (509 KB transferred)
Info::
18 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
509 KB / 2.4 MB budget
509 KB transferred
18 requests
0.10 g CO2 per page load
JavaScript 474.4 KiB 93%
CSS 21.4 KiB 4%
HTML 11.8 KiB 2%
Other 718 B 0%
Other 547 B 0%
Other 147 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Image Optimization
No images on this page
PASS
No images on this page
Info::
No images on this page
0 images 0 KB
0 oversized -0 KB
0 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
131ms total JS execution
PASS
131ms total JS execution
Info::
https://pennycalc.com/: 74ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-8DBK...: 58ms CPU time
Info::
Third-party scripts: 58ms (44% of total)

Main Thread Breakdown

Script Evaluation 52% Other 20% Style & Layout 11% Script Parsing & Compilation 10% Rendering 6%
ScriptTotalScriptingParse/CompileParty
https://pennycalc.com/74ms6ms1ms1st
https://www.googletagmanager.com/gtag/js?id=G-8DBKHCRCKZ58ms49ms8ms3rd
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
PASS
HTTP/3 advertised via Alt-Svc
Info::
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+
Main HTML Cache-Control
Main HTML max-age=0 (≤ 5min) is appropriate
PASS
Main HTML max-age=0 (≤ 5min) is appropriate
Info::
Main HTML max-age=0 (≤ 5min) is appropriate
Got: public, max-age=0, must-revalidate
A+
Server Response Intelligence
2 server-response signal(s) detected
PASS
2 server-response signal(s) detected
Info::
`Vary` header declared: accept-encoding
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
No `ETag` or `Last-Modified` -- conditional GET not supported
Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.
Network Waterfall
18 requests over 968ms
INFO
0 ms 500 ms 1.0 s FCP 467 ms LCP 531 mshttps://pennycalc.com// https://pennycalc.com/ — 200 — 11.8 KiB — 108 ms — h3https://www.googletagmanager.com/gtag/js?id=G-8DBKHCRCKZwww.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-8DBKHCRCKZ — 200 — 158.0 KiB — 242 ms — h2https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-7877367868278158pagead2.googlesyndication.com/pagea... https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-7877367868278158 — 200 — 54.0 KiB — 200 ms — h3https://pennycalc.com/_astro/index.DcT4rkL-.css/_astro/index.DcT4rkL-.css https://pennycalc.com/_astro/index.DcT4rkL-.css — 200 — 9.3 KiB — 50 ms — h3https://pennycalc.com/_astro/index.CiX8D4Wu.css/_astro/index.CiX8D4Wu.css https://pennycalc.com/_astro/index.CiX8D4Wu.css — 200 — 12.1 KiB — 60 ms — h3https://pennycalc.com/scripts/tween-numbers.js/scripts/tween-numbers.js https://pennycalc.com/scripts/tween-numbers.js — 200 — 2.0 KiB — 41 ms — h3https://static.cloudflareinsights.com/beacon.min.jsstatic.cloudflareinsights.com/beaco... https://static.cloudflareinsights.com/beacon.min.js — 200 — 11.4 KiB — 67 ms — h2https://pagead2.googlesyndication.com/pagead/managed/js/adsense/m202605040101/show_ads_impl_fy2021.jspagead2.googlesyndication.com/pagea... https://pagead2.googlesyndication.com/pagead/managed/js/adsense/m202605040101/show_ads_impl_fy2021.js — 200 — 177.1 KiB — 147 ms — h3https://region1.google-analytics.com/g/collect?v=2&tid=G-8DBKHCRCKZ&gtm=45je6562v9245692971za200zd9245692971&_p=1778412698253&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1094782883.1778412698&frm=0&pscdl=noapi&rcb=15&sr=800x600&uaa=x86&uab=64&uafvl=Not%252FA)Brand%3B99.0.0.0%7CChromium%3B148.0.7778.96&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938465~115938469~118463261&sid=1778412698&sct=1&seg=0&dl=https%3A%2F%2Fpennycalc.com%2F&dt=PennyCalc%20%E2%80%94%20Financial%20Calculators%20That%20Show%20the%20Math&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=409region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-8DBKHCRCKZ&gtm=45je6562v9245692971za200zd9245692971&_p=1778412698253&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1094782883.1778412698&frm=0&pscdl=noapi&rcb=15&sr=800x600&uaa=x86&uab=64&uafvl=Not%252FA)Brand%3B99.0.0.0%7CChromium%3B148.0.7778.96&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938465~115938469~118463261&sid=1778412698&sct=1&seg=0&dl=https%3A%2F%2Fpennycalc.com%2F&dt=PennyCalc%20%E2%80%94%20Financial%20Calculators%20That%20Show%20the%20Math&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=409 — 204 — 547 B — 67 ms — h2https://fundingchoicesmessages.google.com/i/ca-pub-7877367868278158?href=https%3A%2F%2Fpennycalc.com&ers=2fundingchoicesmessages.google.com/i... https://fundingchoicesmessages.google.com/i/ca-pub-7877367868278158?href=https%3A%2F%2Fpennycalc.com&ers=2 — 200 — 70.2 KiB — 233 ms — h2https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw==fundingchoicesmessages.google.com/e... https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw== — 204 — 28 B — 125 ms — h3https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw==fundingchoicesmessages.google.com/e... https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw== — 204 — 28 B — 127 ms — h3https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw==fundingchoicesmessages.google.com/e... https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw== — 204 — 28 B — 120 ms — h3https://fundingchoicesmessages.google.com/f/AGSKWxV8ebbDZELfXCJaW2o7QDZ583s2BjHsMl1W12pI3ovIRqiRUyvp8wpBtHjPsRF7fmL0WyBJiTHCKhulFP7MPPVnz8EHgyA0T-BdeX88TnwqkXViBQ0lxm6QTwrmuvMpdbJ2D9LIGA==?fccs=W251bGwsbnVsbCxudWxsLG51bGwsbnVsbCxudWxsLFsxNzc4NDEyNjk4LDg3NTAwMDAwMF0sbnVsbCxudWxsLG51bGwsW251bGwsWzddXSwiaHR0cHM6Ly9wZW5ueWNhbGMuY29tLyIsbnVsbCxbWzgsIlJpYXFiblNJNWVjIl0sWzksImVuLVVTIl0sWzE4LCJbW1tudWxsLDUwOF1dXSJdLFszNSwiMTc3ODQxMjY5OCJdLFsxOSwiMSJdLFsxNywiWzBdIl0sWzI0LCIiXSxbMjksInRydWUiXV1dfundingchoicesmessages.google.com/f... https://fundingchoicesmessages.google.com/f/AGSKWxV8ebbDZELfXCJaW2o7QDZ583s2BjHsMl1W12pI3ovIRqiRUyvp8wpBtHjPsRF7fmL0WyBJiTHCKhulFP7MPPVnz8EHgyA0T-BdeX88TnwqkXViBQ0lxm6QTwrmuvMpdbJ2D9LIGA==?fccs=W251bGwsbnVsbCxudWxsLG51bGwsbnVsbCxudWxsLFsxNzc4NDEyNjk4LDg3NTAwMDAwMF0sbnVsbCxudWxsLG51bGwsW251bGwsWzddXSwiaHR0cHM6Ly9wZW5ueWNhbGMuY29tLyIsbnVsbCxbWzgsIlJpYXFiblNJNWVjIl0sWzksImVuLVVTIl0sWzE4LCJbW1tudWxsLDUwOF1dXSJdLFszNSwiMTc3ODQxMjY5OCJdLFsxOSwiMSJdLFsxNywiWzBdIl0sWzI0LCIiXSxbMjksInRydWUiXV1d — 200 — 1.8 KiB — 86 ms — h2https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw==fundingchoicesmessages.google.com/e... https://fundingchoicesmessages.google.com/el/AGSKWxXAn7jS03TXSnPDE1LdLGGgIWmHt0HwyX3il0rdmHroKJ-iA-Zc2T43mgvup_HUgsjTN9xDugJWGU9jptyH7LyA7SMgBOxkEL62ouRxXRfD5nq9zAmTNOSlGN21maRFKiRxFbLhKw== — 204 — 28 B — 72 ms — h3https://cloudflareinsights.com/cdn-cgi/rumcloudflareinsights.com/cdn-cgi/rum https://cloudflareinsights.com/cdn-cgi/rum — 200 — 0 B — 59 ms — h2https://pennycalc.com/favicon.svg/favicon.svg https://pennycalc.com/favicon.svg — 200 — 718 B — 32 ms — h3https://cloudflareinsights.com/cdn-cgi/rumcloudflareinsights.com/cdn-cgi/rum https://cloudflareinsights.com/cdn-cgi/rum — 204 — 35 B — 25 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
44% of JavaScript execution is third-party
First-party Third-party 58ms · 158KB · €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 58ms
Transfer 158 KB
Unused 42%
Monthly Cost €1/mo

44% of JavaScript execution time comes from third-party scripts.

Why this matters

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

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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