If you’ve ever been to a stunning, interactive website that makes you simultaneously want to throw confetti in the air and share it with your friends, there’s a good chance it was built with JavaScript.
In fact, any site that uses Google Analytics (and other tracking tools) or features interactive elements or web applications also uses JavaScript, a nearly omnipresent coding language. The possibilities are limitless.
The downside? If done wrong, it can tank your SEO. So, how can you use JavaScript SEO to your advantage and boost your search performance? Let’s dive in.
How to Make Your JavaScript SEO-Friendly
What is JavaScript SEO?
Before defining JavaScript SEO — let’s talk about the most common use cases for JavaScript. In addition to website development, JavaScript is an excellent option for gaming, computer programs, and more.
In web development, it’s primarily used for an interactive website, web and mobile apps, and dynamic content.
Once you know how the programming language is used, JavaScript SEO is simply about ensuring search engines can easily find any site built with JavaScript.
If your understanding of SEO is primarily limited to keyword optimization, you’re far from alone. There are ultimately three types of SEO — on-page, off-page, and technical.
On-page SEO focuses on the content that’s on your site (keyword optimization). Off-page SEO is concerned with your site’s reputation, popularity, and usefulness — and is mainly out of your control.
JavaScript SEO falls under the third category — technical SEO — which focuses on ensuring your site is searchable, indexable, and crawlable so people searching for the information you offer can find it.
Want to learn more about On Page and Technical SEO? Grab our free tutorial here!
How to Make Your JavaScript SEO-Friendly
Most of the JavaScript used on websites, including yours and mine, won’t significantly impact SEO. The biggest challenge comes when your developer uses JavaScript to build sections with lots of important information or entire pages.
The reason is simple: JavaScript can make it more difficult for search engines to read your site.
1. Use dynamic rendering (sparingly) as a workaround.
One of the most significant issues with JavaScript SEO and indexing relates to how your code is rendered — or how Google indexes (or doesn’t index) your site.
That means you must understand how your site can be rendered — server-side rendering, client-side rendering, and dynamic rendering.
Server-Side Rendering (SSR)
What it is: When JavaScript is rendered on the server before appearing in your browser or to Google’s crawlers.
How it affects SEO: It reduces the load time for your page’s most important content, which increases SEO performance.
The downside of SSR: SSR can drastically increase the time required if you need user inputs.
Client-Side Rendering (CSR)
What it is: CSR is when JavaScript is rendered on your browser with only a basic version of HTML, and the rest of the content is delivered via JavaScript.
How it affects SEO: It reduces indexability because most of your content is delivered via JavaScript.
The downside of CSR: While rendering is faster, search performance is much lower, so you’ll need to focus on giving Google as much information as possible so it can index your content appropriately.
Expert tip: Kristina Azarenko, a leading technical SEO expert, says, “Using client-side rendering means Googlebot can’t access any content.
A much better and more successful approach is using server-side rendering, so Googlebot also serves the content from the server.”
Dynamic Rendering
What it is: Dynamic rendering identifies bots that cannot render JavaScript and delivers an SSR version.
How it affects SEO: It allows bots to index a version of your content, which makes it more findable.
The downside of Dynamic Rendering: Ultimately, dynamic rendering is a workaround that Google says shouldn’t be a long-term solution because “it creates additional complexities and resource requirements.”
Dynamic rendering can be used by sites that experience rapid content changes or have content that uses JavaScript that is incompatible with browsers. It’s not the best fit for most sites and doesn’t need to be used on every site page.
2. Use unique, descriptive meta content.
Make sure that Google can easily find out what each page includes using meta content, page titles and meta descriptions. This includes
- Title tags.
- Meta descriptions.
- Alt text and attributes for images.
Adding meta content lets Google figure out what your site or page is about, making indexing your site and pages more straightforward and accurate.
3. Implement lazy loading.
Lazy loading speeds up page loading by serving content only as needed or about to be read. It’s particularly helpful for loading large images or content that requires lots of resources.
Your images and resource-heavy content and elements won’t get loaded with the rest of the top-of-page content, but as users read through the content, they’ll load.
And if your user doesn’t read to the bottom of the page, you won’t load unnecessary images.
The downside is that if you have someone scrolling quickly, they might end up waiting for images to load. What’s more, it may affect how Google sees your web page. So, if you follow this practice, do so carefully.
4. Make sure your JavaScript is compatible with Google.
Go into your Search Console and paste the URL of your specific page into the URL Inspection tool to see how Google renders it.
Want another tool to test? You can also use Google Rich Results Test and Google Mobile Friendly Test to see the rendered HTML.
Expert tip: David Zimmerman of Reliable Acorn recommends using tools like the Google Mobile Friendly Test because they show you what the Google spider sees.
Zimmerman adds that just because “your developer ‘read somewhere’ that Google can read JavaScript doesn’t mean that they understand how to write an SEO-friendly JavaScript website.”
The bottom line here? It’s a good idea to stay on top of things.
5. Fix any search-related errors.
You can preview the tested page once you confirm Google has indexed the page. Google only renders the content it can see, so if the tested page doesn’t appear correctly, Google won’t be able to index it.
Best of all, you can discover what’s happening and why and take steps to resolve the problem.
6. Fix and retest.
Once you’ve fixed any errors related to JavaScript rendering and compatibility, you can use the URL inspection tool to ensure your JavaScript works correctly in live mode and request that Google indexes the updated code.
JavaScript SEO Best Practices
I caught up with several JavaScript SEO experts to learn about their best practices, and we’ll get to those in a moment. However, first and foremost, make sure you’re operating on the latest information.
1. Get a primer on JavaScript SEO.
A lot goes into JavaScript SEO, and with browsers undergoing regular updates, if you haven’t done JavaScript SEO in a while, you may need a primer.
If you need to revisit what search engines are looking for when it comes to JavaScript or get detailed instructions about what to fix — and how — Google breaks down everything you need to know in Google Search Central.
It’s the secret weapon of anyone with a website because it tells you exactly how to make your website SEO-friendly — and it includes an entire section dedicated to JavaScript.
2. Put all important content into the source code.
Remember how I mentioned that Google can only index what it can see? To ensure your site is indexable, follow Azarenko’s advice and “make sure JavaScript issues don’t break your SEO efforts.”
She recommends “ensuring all-important content is available in the source code (i.e. before JavaScript is executed). This allows Google to ‘read’ your information without depending on JavaScript.
Include all metadata (title, meta robots, canonical tags, etc.), body copy, and structured data.”
3. Regularly test your site for JavaScript SEO-friendliness.
Even small edits to your JavaScript code or content can change how Google sees your site. And this isn’t limited to your JavaScript — using tools like Google Search Console to monitor page performance can help ensure your site stays at the top of search results.
Expert tip: Tristan Harris recommends using tools like Google PageSpeed Insights and Lighthouse to test SEO performance and identify improvement areas.
Best Practice #4. Stay on top of Google’s Guidelines.
Google regularly updates its algorithms — and, therefore, its best practices. With that in mind, paying attention to Google’s page for updates is a good idea.
Zimmerman recommends using a page monitor like Hexomatic to keep up with Google’s guidelines for JavaScript SEO, “If the page monitor shows me Google has made an update, I check it out to see if it should change my processes in any way.”
Best Practice #5. Follow best on-page SEO practices.
Sure, I’m focusing on JavaScript SEO specifically here, but the key principles of SEO still apply. While JavaScript can reduce the amount of content search engines see, ensuring your content is optimized for best SEO practices is still essential.
Expert tip: Dave Ver Meer recommends disabling JavaScript.
“It’s the quickest way to identify a range of larger issues. When you visit pages on your site, you can find red flags like missing content because it’s not being rendered before the page loads and if some links don’t work,” Ver Meer says.
Trying It Out
To test my new skills in a relatively (read: completely) safe environment, I went to my sometimes-friend, sometimes-nemesis ChatGPT.
My prompt: “I want to create a Javascript code form to collect leads. Please use fun placeholders for name, email, budget, and message.”
GPT’s response: “Certainly! Below is a simple example of a JavaScript form that collects leads. This form includes fields for name, email, budget, and a message. I’ve added fun placeholders, as you requested.
The form also includes basic validation to ensure that the name, email, and message fields are not left empty.”
Here’s the HTML for the form.
As for the fun placeholders? Well, GPT thought Iron Man would be fun. Here’s what the full code in HTML looks like:
And here’s the JavaScript:
Of course, ChatGPT had a disclaimer:
Now for the fun part. Let’s see how ChatGPT optimizes this JavaScript for SEO.
Unsurprisingly, the HTML version of the code was considerably more robust. I’ve broken it up into two sections so you can compare the differences. (I’ll spell them out below.)
The body looks quite similar, with most changes related to the hypothetical lead gen page content.
Now, let’s look at the updated JavaScript.
Does it look familiar? Let’s compare the code side by side.
They’re identical. Surprised?
Here’s why.
My brand-new JavaScript code is responsible for the functionality of my brand-new lead gen form.
And only the functionality.
It’s not responsible for the structure or “page” content. That’s where the HTML comes in. And that’s also where recommendations for SEO optimization apply.
How I Used ChatGPT to Optimize JavaScript SEO
Are you wondering about the specific changes ChatGPT recommended to optimize the JavaScript SEO?
Change 1. Add a page title & meta description.
Change 2. Use heading tags.
Change 3. Label form fields for SEO and accessibility.
Change 4. Add alt text to images.
Change 5. Use responsive design to make the page mobile-friendly.
Change 6. Add schema markup to help search engines understand the content of your page.
The Bottom Line of JavaScript SEO
Deciding to use JavaScript on your website requires understanding the implications for SEO and planning accordingly to ensure your site remains SEO friendly — or findable, crawlable, and indexable by search engines.
This is not meant to caution you against JavaScript. On the contrary, to make the most of your interactive features, it’s necessary to find and hire developers who understand JavaScript and SEO and can help you stand out while getting found.
The biggest takeaway? The most important thing you can do to make your JavaScript SEO-friendly is to ensure that it renders correctly and that your page HTML is structured to provide as much information as possible about the page’s content.
Perhaps surprisingly (and perhaps not), the rules of on-page SEO apply to JavaScript SEO — the key lies in ensuring search engines can “see” your content.
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