Semrush Website Audit Can Now Render JavaScript

Does your web site use JavaScript (JS)? It most likely does like most web sites.

If that’s the case, you should utilize our Website Audit device to uncover extra points than earlier than.

Google renders your webpages’ unloaded JS to see its full content material and to ensure your on-line guests can simply entry the whole lot too. Now, our Website Audit bots render JavaScript in the identical approach to determine any hidden points in your web site. 

Right here’s how we had been ready to try this. 

What’s New in Website Audit?

We’ve allotted extra sources so we are able to crawl and render your web site’s JavaScript. This implies we are able to accurately crawl websites largely constructed on JavaScript, even when they’re client-side rendered. 

To indicate you the distinction, check out a earlier than and after:

This is one audit with JS rendering enabled and one other audit (of the identical web site) with JS disabled.


See the large distinction between the variety of errors and warnings earlier than and after? With JS enabled, it could correctly determine the problems that must be fastened. 

How Does JavaScript Affect web optimization and Why Does It Matter?

JavaScript rendering is when a web site’s JavaScript information are correctly executed and exhibited to web site guests. 

How these information flip from strains of code to an interactive web site in your browser can occur in a number of methods (like client-side vs. server-side rendering). Every has its professionals and cons. Nevertheless, websites that use JS and client-side rendering may run into crawling issues, particularly for tech audit bots. 

Why does that occur? In brief, it comes right down to sources.

Google has the sources to load each static HTML and injected HTML as soon as a web site’s JS is executed. However some web site auditing bots don’t have the sources to deal with that job (like ours earlier than this replace). 

Right here’s what Airbnb would seem like to a bot that may’t render JS. 


And right here’s what it might seem like to a bot that may execute and render JavaScript. 


What Occurs When Google Renders a Website’s JavaScript? 

When Google renders a web site’s JavaScript, it first sees if any JS must be executed within the first place. If it does, it goes right into a queue after which will get executed/rendered to disclose the webpage’s full content material. Then, Google indexes it.

Right here’s what that appears like:


Up to now, we weren’t capable of execute that stage above the place a bot processes the JavaScript and renders it. Now our course of is analogous (minus the indexing). 

Why Ought to You Allow JS Crawling in a Website Audit?

You won’t see the total image of your web site’s points with out enabling JS in your subsequent web site crawl. 

Enabling JS may provide help to discover related points that had been doubtlessly missed earlier than.

Particularly for websites constructed on the app shell mannequin (the place core elements are loaded, however often not the majority of a web site’s content material—consider the sooner Airbnb instance). 

Some JavaScript websites might use the app shell mannequin the place the preliminary HTML doesn’t comprise the precise content material and Google must execute JavaScript earlier than having the ability to see the precise web page content material that JavaScript generates.

– Google

How Does Website Audit JavaScript Rendering Work Now?

1. We obtain the preliminary HTML from the online server throughout crawling

2. We load the JS sources which can be linked on this HTML

3. Execute and render JS code 

4. Wait 5 seconds

5. Website Audit makes use of the ultimate HTML for additional evaluation steps

While you select to disable JS in Website Audit, we use the unique HTML as we did earlier than. 

Does Enabling JS Have an effect on My Limits? 

No, it is not going to have an effect on your limits in case you select to allow JS on Website Audit. Nevertheless, solely these with Guru or Enterprise subscriptions can use this characteristic.

Will It Set off Trackers, Advertisements, and Occasion Handlers? 

No, Website Audit is not going to set off trackers, advertisements, and occasion handlers (i.e. JS triggered by clicking or scrolls). Right here’s what we block when our Website Audit bot crawls a web site: 

  • GA4
  • GA3
  • Yandex Metrica
  • Amplitude
  • Adobe Analytics
  • Google Advertisements
  • OWOX
  • SpeedCurve

Does Website Audit Use Chrome for Rendering JS?

Sure, we use the newest Chromium rendering engine. So, we use the identical know-how as Google does for crawling. 

Easy methods to Crawl Your Website’s JS with Website Audit

Crawling your web site’s JS with Website Audit is straightforward. First, go to the Website Audit device and click on the ‘create undertaking’ button. 


Subsequent, it’ll immediate you to arrange the audit. The one distinction is that you just’ll select ‘enabled’ for ‘JS-rendering’ within the crawler settings. You’ll be able to nonetheless go away it disabled in case you’d like or change it later. 


You’ll be able to verify in case your audit is rendering your web site’s JS by wanting up right here within the report: 


Easy methods to Crawl an Current Challenge’s JS with Website Audit

If JS rendering isn’t enabled on a present undertaking, you may change that within the Website Audit settings. 


From right here, simply click on the “re-run marketing campaign” button to crawl your web site with JS enabled. You’ll be able to disable JS rendering in the identical means if you wish to change it again later. 

Discover All Of Your Website’s Points with JS Rendering

JavaScript makes websites extra interactive, dynamic, and customized. For instance, Netflix makes use of JS to replace the physique of a single net doc for a speedy, seamless expertise. 

Equally, many web sites use the app shell mannequin (in addition to client-side rendering) to profit each the person agent and the location proprietor in their very own methods. Your web site might use JS to attain the identical outcomes. And in case your web site does, we are able to determine what points Google might run into with Website Audit’s new JS rendering characteristic.