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https://www.proton.me

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
87
GRADE
B
FIX
2
REVIEW
4
PASS
6
INFO
2

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

Mobile Desktop
90
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
84
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

840 ms

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

1.87 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.

0.071

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

840 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.

1.90 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 s
Checks
14
6 PASS 4 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (1.2 MiB of 1.2 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

B
Page Weight Budget
1.2 MB transferred, 142 requests
REVIEW
1.2 MB transferred, 142 requests
Info::
Page weighs 2.1 MB (1.2 MB transferred)
Warning::
142 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.24 g CO2 per page load
1.2 MB / 2.4 MB budget
1.2 MB transferred
142 requests
0.24 g CO2 per page load
Images 499.3 KiB 42%
JavaScript 433.1 KiB 37%
Fonts 129.4 KiB 11%
CSS 48.9 KiB 4%
HTML 32.6 KiB 3%
Other 17.7 KiB 2%
Other 16.7 KiB 1%
Other 2.3 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

B
Image Optimization
39 images, 0 KB saveable
REVIEW
39 images, 0 KB saveable
Info::
All images are well-optimized
39 images 499 KB
0 oversized -0 KB
23 legacy format
0 missing dimensions CLS risk
B
JS Execution Cost
696ms total JS execution
REVIEW
696ms total JS execution
Warning::
https://proton.me/_astro/client.B0lLcFr3.js: 269ms CPU time
Info::
https://proton.me/: 241ms CPU time
Info::
Unattributable: 185ms CPU time
Warning::
Third-party scripts: 696ms (100% of total)

Main Thread Breakdown

Other 46% Script Evaluation 27% Parse HTML & CSS 14% Style & Layout 6% Rendering 5%
ScriptTotalScriptingParse/CompileParty
https://proton.me/_astro/client.B0lLcFr3.js269ms150ms0ms3rd
https://proton.me/241ms35ms9ms3rd
Unattributable185ms14ms0ms3rd
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

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+
Font Loading
3 fonts (129 KB)
PASS
3 fonts (129 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

129 KB total

Render-blocking

0

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s FCP 840 ms LCP 1.9 shttps://proton.me/fonts/inter/InterVariable.en.woff2InterVariable.en.woff2 https://proton.me/fonts/inter/InterVariable.en.woff2 — 44.9 KiB — 0 ms — font-display: swaphttps://proton.me/fonts/arizona/ABCArizonaFlareVariable.en.woff2ABCArizonaFlareVariable... https://proton.me/fonts/arizona/ABCArizonaFlareVariable.en.woff2 — 71.4 KiB — 0 ms — font-display: swaphttps://proton.me/fonts/syne/Syne-Medium.en.woff2Syne-Medium.en.woff2 https://proton.me/fonts/syne/Syne-Medium.en.woff2 — 13.2 KiB — 0 ms — font-display: swap
InterVariable.en.woff2 woff2 swap
Size 45 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ABCArizonaFlareVariable... woff2 swap
Size 71 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Syne-Medium.en.woff2 woff2 swap
Size 13 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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)
A+
JS Bundles
85 scripts, 23 KB unused
PASS
85 scripts, 23 KB unused
Warning::
https://proton.me/_astro/DropdownButton.DR7HMx3f.j...: 23 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 23 KB
23 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://proton.me/_astro/DropdownButton.DR7HMx3f.js39 KB23 KB (63%)✓3rd
https://proton.me/_astro/FrameworkHead.astro_astro_type_script_index_0_lang.CkvChNH1.js2 KB—✓3rd
https://proton.me/_astro/singleton.C4hEIpiU.js9 KB—✓3rd
https://proton.me/_astro/index.DVtoBYpv.js15 KB—✓3rd
https://proton.me/_astro/post.2rEtNZZz.js4 KB—✓3rd
https://proton.me/_astro/_commonjsHelpers.D6-XlEtG.js2 KB—✓3rd
https://proton.me/_astro/logger.BC5XZLUE.js9 KB—✓3rd
https://proton.me/_astro/FrameworkClient.emXxxRga.js5 KB—✓3rd
https://proton.me/_astro/client.B0lLcFr3.js58 KB—✓3rd
https://proton.me/_astro/HeaderDefault.CaUIHrCg.js3 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

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
Network Waterfall
142 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 696ms · 91KB · CHF11/mo
proton.me
Other
Costly
Execution 269ms
Transfer 58 KB
Monthly Cost CHF4/mo
proton.me
Other
Costly
Execution 241ms
Transfer 33 KB
Monthly Cost CHF4/mo
Unattributable
Other
Optional
Execution 185ms
Transfer 0 KB
Monthly Cost CHF3/mo

These scripts may cost more than they're worth

  • proton.me adds 269ms and costs ~CHF4/month
  • proton.me adds 241ms and costs ~CHF4/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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

proton.me takes 269ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

proton.me takes 241ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

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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