Lighthouse Audit: Improve index.html Performance, Accessibility, and Best Practices #19
Description
Summary
This issue tracks all actionable findings from the latest Lighthouse audit for index.html. Addressing these will improve site performance, accessibility, SEO, and compliance with web best practices.
Performance
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Reduce Total Blocking Time (TBT)
- Max Potential FID: 1,360ms. Interactive: 6.9s.
- Suggested fix: Minimize main thread work, optimize scripts, defer non-critical JS, and reduce third-party impact.
- Reference: Lighthouse TBT docs
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Optimize Server Response Time
- Guidance Level: 1
- Suggested fix: Use CDN, optimize backend, and enable caching for static assets.
- Reference: Lighthouse server response docs
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Preconnect to Required Origins
- uses-rel-preconnect: Guidance Level 3
- Suggested fix: Add
<link rel="preconnect">for third-party resources (e.g., img.shields.io, unpkg.com) in<head>. - Reference: Preconnect docs
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Font Display Optimization
- font-display: Guidance Level 3
- Suggested fix: Add
font-display: swapto custom font CSS or use Google Fonts withdisplay=swap. - Reference: Font display docs
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Reduce Bootup Time and Main Thread Work
- bootup-time, mainthread-work-breakdown: Guidance Level 1
- Suggested fix: Audit scripts, remove unused JS, and split code for faster load.
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Optimize Image Delivery
- unsized-images, prioritize-lcp-image, lcp-lazy-loaded, uses-optimized-images, uses-responsive-images, modern-image-formats: Guidance Level 2-4
- Suggested fix: Add explicit width/height to images, use responsive images (
srcset), and prefer modern formats (WebP/AVIF). - Reference: Image optimization docs
Accessibility
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Ensure Viewport Meta Tag is Present and Valid
- viewport: Guidance Level 3
- Suggested fix: Confirm
<meta name="viewport" content="width=device-width, initial-scale=1">is present and correct.
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Improve Color Contrast
- Suggested fix: Audit text/background color pairs for sufficient contrast.
- Reference: Color contrast docs
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Add Alt Text to All Images
- Suggested fix: Ensure all
<img>tags have descriptivealtattributes.
- Suggested fix: Ensure all
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Check Heading Order and Structure
- Suggested fix: Use headings in a logical order (H1, H2, H3, etc.) and avoid skipping levels.
Best Practices
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Minify CSS and JavaScript
- unminified-css, unminified-javascript: Guidance Level 3
- Suggested fix: Minify all CSS/JS assets before deployment.
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Remove Unused CSS and JavaScript
- unused-css-rules, unused-javascript: Guidance Level 1
- Suggested fix: Audit and remove unused code from bundles.
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Use Passive Event Listeners
- uses-passive-event-listeners: Guidance Level 3
- Suggested fix: Add
{ passive: true }to event listeners for scroll/touch events.
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Enable HTTP/2
- uses-http2: Guidance Level 3
- Suggested fix: Serve site and assets over HTTP/2 for faster loading.
SEO
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Optimize Meta Description
- Suggested fix: Ensure
<meta name="description">is present and concise.
- Suggested fix: Ensure
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Add Canonical and Hreflang Tags
- Suggested fix: Add
<link rel="canonical">and<link rel="alternate" hreflang="...">as appropriate.
- Suggested fix: Add
References
Please address each checklist item in a separate PR or commit.
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Labels
Validation, deduplication, and ensuring output accuracy (e.g., phone/email rules).Writing/updating docs, runbooks, manpages, and README sections.Operational aspects like scheduling, logging, monitoring, and production readiness.Quality assurance, manual testing, and final verification runs.Improving fetch reliability, retries, timeouts, and error handling.