How to Fix Rendering Problems for SEO – JavaScript & HTML Rendering Fix Guide

Your website might just be flying under the radar for Google. And if search engines can’t even see your content, odds are you’re not going to rank. The fix is pretty straightforward – make sure Googlebot is getting a fully formed HTML page to index. And for that, you need to kick your client-side rendering habit and get a different approach going. That means implementing server-side rendering, dynamic rendering or making sure you’ve got the right resources in place so your content is visible to Google without any hiccups.

Key Takeaways

• If Googlebot can’t run your JavaScript, you’re likely going to end up with a page that looks like it has a blank page in search results – courtesy of Google.
• Server-side rendering (SSR) is your best bet here as it delivers a complete HTML page to search engines nice and quick.
• One of the most common causes of rendering failures is if you’ve got blocked JavaScript and CSS files hiding in your robots.txt.
• Dynamic rendering can be a decent option especially for big JavaScript frameworks like React or Angular.
• You need to test your rendered HTML using tools like Google Search Console and Screaming Frog to make sure your fixes are actually working.

What are these Rendering Problems in SEO all About?

Rendering problems in SEO mean Google just isn’t seeing your content – which is the last thing you want when it comes to ranking. When Googlebot swings by your page, you might see a blank screen or all the text just missing instead of the content you’re trying to rank for. This happens when your website is relying way too heavily on JavaScript to build that page.

These days, we’re all about building websites with modern stuff like React, Angular, or Vue. These tools all use client-side rendering. Essentially, the server sends a basic HTML shell to the browser and then JavaScript does all the heavy lifting to pull in content and actually build the page. Search engines can run JavaScript, but it takes time, resources – and sometimes it just fails.

The main reasons why you’re going to hit rendering problems are:

• Those JavaScript-heavy sites that require execution to show up any content.
• Using client-side rendering as the sole way to display content.
• Blocking off JavaScript or CSS files in your robots.txt that Googlebot just can’t access.
• Lazy loading which delays important content until the user interacts with it.
• Slow API calls that just can’t deliver content within Google’s rendering window before the page times out.

When your Googlebot hits these issues, it ends up indexing incomplete pages. And that’s a big no-no when it comes to ranking because search engine just isn’t going to understand what your page has to offer.

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Why Rendering Problems Hurt SEO

Rendering problems can do some serious damage to your search visibility. The consequences of Google not being able to render your content properly will be felt across every area of your SEO performance

Content not getting indexed: When Googlebot sees a blank page, it just can’t index your text, images, or videos. That means those pages will not show up in search results at all.

Wrong indexing: Sometimes Google will only index a partial version of your content. You might get ranked for the wrong keywords because that incomplete page is giving the wrong idea about what your site is about.

Missing text: Important stuff like headings, product descriptions, and article content may never even make it to the index. That means your authority on a given subject will go unrecognized.

Fix 1 – Use Server-side Rendering (SSR)

Server-side rendering is the top solution for rendering problems. When you use SSR, your server builds the full HTML page before sending it to the browser. That means Googlebot gets a complete document straight away, without having to run any JavaScript.

Benefits of SSR:

• The HTML is available from the first request.
• There’s no delay in rendering for search engines.
• Your site’s crawl efficiency improves.
• Your content is always there for readers and search engines alike.

Frameworks like Next.js for React and Nuxt.js for Vue make SSR a whole lot easier to implement. You can still build JavaScript applications but these will deliver static HTML to search engines.

Of course, using SSR does mean you need more server resources. Your hosting costs may go up a bit. But for most business-critical pages, the SEO benefits are worth the technical investment.

For a more in-depth look at the different approaches, read our analysis of client-side vs server-side rendering SEO.

Fix 2 – Use Dynamic Rendering For Bots

Dynamic rendering is a bit of a stopgap solution for existing JavaScript applications. It detects when a search engine bot visits your site and then serves up a pre-rendered, static HTML version to the bot, while regular users still get the JavaScript experience.

Dynamic rendering works well for:

• React applications.
• Angular frameworks.
• Single-page applications (SPAs).
• Large sites where doing full SSR right now will be too complicated to implement quickly.

You can implement dynamic rendering using services like Rendertron or Puppeteer. These tools generate static HTML snapshots of your pages and store them. When Googlebot requests a page, the system just delivers the static version straight off.

When to use dynamic rendering:

• Your site already uses client-side rendering.
• You can’t switch to SSR right away.
• You have a lot of pages with similar structures.
• SEO performance for these pages is super important.

Dynamic Rendering Creates a Clear Divison between the Bot & User Experience
This approach has historically been acceptable for Google – just as long as the content stays the same. The bot gets to see what the user sees – only just a bit sooner.

Fix 3 – Allow JS & CSS in robots.txt

One of the biggest causes of rendering problems is blocked resources. Far too many websites have a robots.txt file that blocks off their JS and CSS files. That’s a big mistake, because Googlebot can’t do its job if it can’t get to those files. The result is a page in the search results that’s either blank or incomplete.

The problem
Googlebot needs to be able to access JS and CSS files in order to build your page – and it can’t do that if they’re blocked. You might not have even realised the issue – but it’s something that’ll be stopping Google from seeing your page in all its glory.

Example of a blocking robots.txt entry:
remove the following

Disallow: /js/

Disallow: /css/

The fix
Just remove the rules that block access to JS and CSS files. It’s still okay to block other resources if you need to – for example, if you have admin panels or internal tools that you don’t want search engines to see.

Correct approach:

User-agent: Googlebot

Allow: /js/

Allow: /css/

Disallow: /admin/

Take a look at your robots.txt file right now and check for any disallow rules that block off your js and css files. If you find any – get rid of them. They’re costing you SEO.

Fix 4 – Avoid Overdoing Client-Side Rendering

When you’re rendering on the client side, you’re giving the browser all the work to do. That means the server only sends over a minimalist HTML file, and then the browser has to go and build the rest using JavaScript. This can cause delays that search engines may not put up with.

What happens when you have too much JavaScript:
Your page takes a long time to load

• That leads to a higher chance of timeout failures
• And even if the rest of the page does load – if it’s a big page, search engines might not manage to get it all indexed
• And to cap it all off – your users are probably getting a pretty poor experience too. Which means they’re more likely to bounce off your site

How to sort out heavy client-side rendering:

• Get rid of any unused libraries or code – and use code splitting to load only what you actually need on each page.
• Preload the bits of content that are most important – don’t rely on JavaScript to get them to load.
• Use server-side rendering for pages that drive your business – there’s no need to put users and search engines through all that hassle.
• If you’re using third-party scripts – try to limit their impact on your site – they can really add to the loading time.

Search engines have limits on how long they’re prepared to wait for a page to load. If your site takes too long – then sorry, your content is simply not going to get indexed – regardless of how good it is.

Fix 5 – Fix Lazy Loading Issues

Lazy loading can give you a speed boost by only loading content after the user scrolls to it – works a treat for images and videos though. But here’s the catch – it can make your most valuable content invisible to search engines.

The lazy loading problem is: Googlebot won’t scroll your page. If you’ve got important content that only loads after scrolling, well the bot may never even see it. Which means you end up with pages that get indexed but are missing the bits that really matter.

Getting lazy loading and SEO to play nice:

• Get your most important stuff out of the lazy loading queue: Any text headings or links that are above the fold should load straight away without any delay.
• Use the right lazy loading attributes: When it comes to images use the loading=”lazy” attribute. This tells the browser to take its time to load while still letting search engines get a sniff of what’s on the image.
• Leave text content off the lazy loading list: Never lazy load text, headings or internal links. These need to be there right from the get go – in the initial html or at least rendered early doors.

Google is getting the hang of scrolling and interacting with pages but relying on that’s still a bit of a gamble. Keep your essential content outside of the lazy-loaded zone.

Fix 6 – Fix API Content Not Showing Up

Lots of websites now pull in content from APIs. The server sends across an empty page, and then some JavaScript comes along and fetches the content from the API to make the page look pretty. If the API call fails or takes ages to complete Googlebot just sees nothing.

The API problem is:
You’ve got your content stored in a database or CMS. It loads up through JavaScript after the page has rendered. The problem is Googlebot may just give up on that API call and you end up with an indexed page that’s missing all the bits that matter.

How to fix your API rendering issues:

• Get server-side rendering up and running: Use SSR to get the API data on the server side. The server builds the page before sending it off to Googlebot.
• Pre-render static pages: If your content doesn’t change that often, just generate a static html file during build time. Send that to all visitors.
• Use static site generation: Tools like Next.js can pre-build pages from API data. These pages load super quick and they’ve got all the content.

The SEO impact of API-based rendering:
When Googlebot can’t get its hands on the content that’s dependent on the API you’re basically throwing away your ranking potential. You’re missing out on chances for featured snippets, image rankings and all the other goodies. Fixing your API rendering makes sure your content makes it into the index

Fix 7 – Test Rendered HTML After Fix

Implementing fixes and verifying that Googlebot can see your content is only half the battle. You need to make sure that what you’ve changed is actually working the way you think it is – which is where testing comes in.

Three Ways to Confirm Googlebot Can See Your Content:

1. Google Search Console’s URL Inspection Tool
   Take a URL and run it through the inspection tool. The live test is a great way to see how Googlebot sees your page. You’ll be able to compare the fetched HTML to the rendered HTML – if they match up then you’re good to go.
2. View Source vs Inspect Element
   When you load your web page, right-click and view the source. This shows you the raw HTML that’s coming from the server. Now fire up the Developer Tools (Inspect) and see what your page looks like after all the JavaScript has run. If these two views look nothing like each other, you likely have some rendering dependencies to sort out.
3. Screaming Frog SEO Spider
   If you’ve got Screaming Frog, fire it up and make sure the JavaScript rendering is turned on. Tell it to render your pages like Googlebot would. What you will get is a report of exactly how much of your content search engines can actually see.

For a more detailed look at how to get this testing workflow sorted, take a look at our guide on test rendering SEO.

And don’t just test once and then forget about it – this kind of thing can come back to bite you at a later date, especially if you are making big changes to your code or CMS.

Fix 8 – Be Careful Not to Fall Foul of Cloaking

When you’re trying to fix your rendering issues, make sure you’re following the rules. Cloaking – where you show one thing to Google and another thing to visitors – is a big no no with Google. And not doing it can get you into trouble – manual penalties are not something anyone wants to deal with.

The Simple Rule:
Search engines should see the same stuff that visitors see. That’s it.

What To Avoid at All Costs:

• Don’t send search engines all the lovely keyword rich HTML, but make visitors see something completely different (like a load of JavaScript generated junk).
• Don’t hide stuff from visitors that you show to Googlebot.
• Don’t use user agent detection to serve up completely different pages to search engines and visitors – that’s just sneaky and will get you into trouble.

Dynamic Rendering: A Double Edged Sword
Dynamic rendering is actually allowed – but be warned, it’s a minefield if you get it wrong. You can’t just send search engines a pre-rendered version of a page if it’s not actually what users see. And don’t even think about using it as a way to manipulate search rankings.

But actually, according to Google’s John Mueller, as long as you’re doing it properly and showing the search engines the same content you show users, then it’s fine. The key is to make sure that what search engines are seeing is absolutely identical to what visitors see. If you can do that, then you can use dynamic rendering to solve your rendering problems without getting into trouble with Google.

Best Practices to Avoid Rendering Problems

Preventing rendering issues is a whole lot easier than having to fix them after the fact. Follow these best practice tips from day one of any web project.

• Use server-side rendering for your SEO core pages: pages that are a major factor in your search visibility like product pages, blog posts and landing pages are a good place to start.
  These pages basically determine how visible your website is to search engines so you want to get this right.
• Give Googlebots the keys to your website: Remove any restrictions on your website that would stop them accessing the JavaScript and CSS files they need. That way they can see exactly how your website works.
• Test your website rendering after every new push. New code can break things, so check it immediately using Google Search Console or Screaming Frog to ensure everything works as expected.
• Avoid heavy use of JavaScript frameworks: Opt for frameworks that support server-side rendering and will play nicely with search engines. If you must use a client-side framework put a dynamic rendering solution in place straightaway.

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The Bottom line

Rendering problems are probably the most common SEO issue faced by modern websites. And yes JavaScript frameworks are very useful and all that, but they can also cause new problems with search engines. But all is not lost – with a clear plan of action you can solve these problems.

Start with a website audit – check the robots.txt file to see if you’ve blocked access to any of your resources. Then test your pages out in Google Search Console to see if they are being indexed properly. If not its time to do some investigation to see whats going wrong.

Depending on your situation you may need to implement one of the two main solutions. Server-side rendering is probably the best option for long-term SEO success. But if you’re already stuck with a JavaScript application then dynamic rendering might be a better option.