JavaScript rendering with Chromium

When to render JavaScript in a site audit, how to install Playwright and Chromium, and what rendering adds to tracking and consent checks.

By default SiteAud!tLint crawls the HTML your server sends, which is what most search engine checks need and is fast. Sites built with React, Vue, Angular or other client-side frameworks can deliver an almost empty HTML shell and build the page in the browser. For those, turn on JavaScript rendering.

Install the rendering component

The option is hidden until the optional Playwright component and Chromium browser are installed. From the app folder (inside the .venv if you use the .bat file):

pip install playwright
playwright install chromium

Restart SiteAud!tLint. Render JavaScript (Chromium) now appears in Settings > Crawl Settings....

What rendering changes

• Titles, headings, links and content added by JavaScript are audited.
• Crawls are slower, because each page loads in a real browser.
• Tracking & Pixels can see which tags really fire while each page loads and scrolls (GA4, Meta, TikTok, Google Ads, LinkedIn, Pinterest, Microsoft Ads, Clarity), read the dataLayer, and list the cookies set.
• Consent checks can detect pixels and tracking cookies that fire before a visitor accepts anything.

When to leave it off

For server-rendered sites such as WordPress, Shopify and most static sites, rendering adds time without changing SEO results. You can still turn it on for one audit to check tracking and consent.

Applies to SiteAud!tLint 0.3 and later. Current version 0.7.1.