Lighthouse and Performance

Lighthouse checks speed, accessibility, web best practices, and SEO. Run it after installation, theme changes, and major upgrades.

Pages to audit

Audit at least:

1. the public home page;
2. the sign-in page;
3. the authenticated cabinet;
4. the heaviest enabled module page, such as shop or market.

Run mobile and desktop audits. Repeat in Russian and English when text length changes the layout.

Chrome DevTools

1. Open the page in an Incognito window.
2. Open DevTools -> Lighthouse.
3. Select Navigation.
4. Enable Performance, Accessibility, Best Practices, and SEO.
5. Run Mobile first, then Desktop.
6. Select Analyze page load.

Disable browser extensions and compare the median of three runs.

Repeatable CLI audit

npx lighthouse https://cabinet.example.com/ \
  --chrome-flags="--headless --no-sandbox" \
  --output=html \
  --output-path=./lighthouse-home.html

For CI, use Lighthouse CI and archive the report. Do not pass production passwords on the command line; use a staging environment and Playwright setup for authenticated pages.

Practical thresholds

Category	Launch minimum	Target
Performance	75	90+
Accessibility	90	95+
Best Practices	90	95+
SEO	90	95+

Performance depends on themes, images, network conditions, and third-party scripts. A regression against the previous release matters more than one isolated score.

Common findings

Large images

Use WebP/AVIF, correct display dimensions, lazy loading below the first viewport, and stable width/height.

Render-blocking assets

Remove unused theme libraries, avoid loading bundles twice, and defer third-party scripts that are not needed for first interaction.

Layout shift

Set stable dimensions for logos, banners, tables, and dynamic blocks. Check RU/EN separately so long translations do not resize buttons or overlap controls.

Slow backend

Check TTFB, API health, database queries, background jobs, and local file cache. A CDN does not fix a slow personalized cabinet.

Accessibility

Fix contrast, field labels, keyboard access to dropdowns, heading order, and focus states. Do not remove focus outlines without an accessible replacement.

After fixes

Repeat the same URLs and modes, compare reports, and store the result with the release version. Then complete the pre-launch checklist.