Over the last few years we have seen JavaScript usage in websites increase significantly, everything from cool scroll effects to fully fledged JavaScript frameworks that build entire web pages within the browser.
However, JavaScript can cause problems from an SEO perspective, so SEOs and developers need to understand how rendering changes page content, and the SEO risks this has associated with it.
15. @HathawayP
The problem with rendering
1. It takes a LOT longer
2. It’s more resource intensive
3. It adds an extra step when crawling
16. @HathawayP
Crawling HTML
1. Download URL content (= View Source)
2. Parse HTML
3. Extract content and links
4. Add href link URLs to crawl scheduler
5. Add URL data to index
17. @HathawayP
Crawling JavaScript
1. Download URL content
2. Render content (= Inspect Element)
3. Parse HTML
4. Extract content and links
5. Add href link URLs to crawl scheduler
6. Add URL data to index
26. @HathawayP
Mobile-first relies on rendering
Mobile-first means that Google will
render your page content using the
mobile version of the page, and use
that to determine indexing and ranking
on EVERY device.
28. @HathawayP
Why is it taking so long? (Guesses)
Two big reasons:
1. They can’t afford for it to not work
properly on the BIG sites.
2. They need to upgrade from Chrome
41 (not good enough at rendering).
30. @HathawayP
What changes when you render?
• Navigation?
• Internal links?
• Page content? (Hidden content?)
• Robots directives?
31. @HathawayP
You need to test rendering to find out
1. Crawl your website with a crawler
that renders JavaScript – Sitebulb and
Screaming Frog can both do this.
2. Compare Source HTML vs the
rendered HTML – excellent guide here:
bit.ly/compare-source