Technical SEO case study: A recent experiment found that Google takes 9x times longer to crawl JavaScript than HTML. Here's what you need to know:
Ziemek Bućko & Marcin Gorczyca of Onely performed a test that compared the crawl times of the same content on standard HTML pages vs vanilla JavaScript. They created these pages in separate folders with 7 pages each.
The test found that:
1. Google took 313 hours to crawl the final JavaScript page vs only 36 hours to crawl the final HTML one.
2. Google crawled the first JavaScript page in 52 hours. Comparatively it only took 25 hours to crawl the first HTML version.
3. The rest of the HTML pages saw significantly decreasing crawl times after the initial one. Conversely, the Javascript version did not see this dramatic reduction.
This is one of the reasons SEOs have a justified fear of JavaScript. While we know Google can technically crawl the content, there are huge efficiency tradeoffs. Sites that rely heavily on JavaScript usage likely come up against Google's limits much faster.
This especially becomes an issue when you're dealing with pages at scale.
Ziemek Bućko & Marcin Gorczyca of Onely performed a test that compared the crawl times of the same content on standard HTML pages vs vanilla JavaScript. They created these pages in separate folders with 7 pages each.
The test found that:
1. Google took 313 hours to crawl the final JavaScript page vs only 36 hours to crawl the final HTML one.
2. Google crawled the first JavaScript page in 52 hours. Comparatively it only took 25 hours to crawl the first HTML version.
3. The rest of the HTML pages saw significantly decreasing crawl times after the initial one. Conversely, the Javascript version did not see this dramatic reduction.
This is one of the reasons SEOs have a justified fear of JavaScript. While we know Google can technically crawl the content, there are huge efficiency tradeoffs. Sites that rely heavily on JavaScript usage likely come up against Google's limits much faster.
This especially becomes an issue when you're dealing with pages at scale.
