A TikToker I watch occasionally , made an interesting point. That people hold strong beliefs in things that are frequently updated. I dont recall the specifics – it was about a restaurant chain including some ingredient that was clearly something they got rid of the 1980s but that doesn’t stop people having full blown arguments about things they “believe” that have 0 foundation in reality.
Web developers when they talk about SEO – and in many cases dismissing it – are firmly in this camp. The most important skill in SEO – as in life – isn’t knowledge, its critical thinking.
The Birth of the Web Spider (aka Crawler)
When the internet was in its infancy – back in the mid 2000’s, this idea of a web spider appeared – and it was a cute, innocuous explanation of how search bots went from site to site, exploring, discovering and assessing content. And Google still appears to be using some of that language today – especially referencing to rendering, which is stricly limited to text fetching but clearly
I want to state this as plainly as I can, leaning on decades of search engine evolution and Google’s own documentation: The idea of a web crawler that fetches, renders, and aesthetically appraises your website’s design in real-time is a fantasy.
I asked Google Gemini what it though:
You’re right. The belief is rampant. I’d estimate that about 40% of SEOs, and a staggering 80% of web developers who dabble in SEO, cling to this notion. They envision Googlebot as a sort of phantom user, scrolling through a virtual browser on a giant screen, judging the pixel distance between your logo and your navigation bar, admiring your parallax effects, and making qualitative judgments about your user experience. This misconception stems from a logical but incorrect leap: because Google values good UX, its bot must be the one evaluating it visually.
A Brief History of Web Crawlers: The Age of Simplicity
To understand where we are, we must see where we came from. Before Google’s dominance, the web was a wild, untamed frontier. The first “search engines” were more like simple archivists, and their tools, the first web crawlers, were rudimentary by today’s standards.
World Wide Web Worm (WWWW)
Launched in 1994, the WWWW is often cited as one of the first crawlers. Its job was simple: identify URLs and index their titles and headers. It wasn’t rendering pages or executing scripts; it was a pure text-retrieval mechanism.
WebCrawler
Also launched in 1994, this was the first crawler to index the full text of the pages it found. This was a revolutionary step, but its mechanism was still straightforward: fetch the HTML document and parse the text within it. There was no concept of “rendering” because pages were just static HTML documents.
JumpStation: This early engine used a crawler with three distinct parts: a “crawler” to find pages, a “gatherer” to fetch and parse them, and an “indexer” to store the data. This early separation of concerns—fetch, process, store—is a critical architectural point that has survived to this day.
The Modern Reality: Googlebot is a Bot, Not a Connoisseur
This is where the confusion peaks. Developers see that Google can now index JavaScript-heavy websites and that it champions Core Web Vitals (CWV), and they connect these dots to create the myth of the design-savvy crawler. But they’re connecting them incorrectly.
Let’s break down Google’s process, based on their own documentation, to separate fact from fiction.
- Crawling (The Fetcher Bot): The first step is still carried out by Googlebot. Think of this as the scout. Its primary job is to add URLs to a queue and then rapidly fetch the resources at those URLs. It does this by making an HTTP request, just like a browser. What it gets back is typically the raw HTML file. At this stage, it is not concerned with your CSS, your brand colors, or the elegance of your animations. It is concerned with speed, efficiency, and respecting robots.txt. This is the “bot” in its purest form—a fetcher.
- Processing & Rendering (The Specialist Service): Here’s the critical distinction. The fetched HTML and all its linked resources (CSS, JS, images) are passed on to a processing service. If the system detects that JavaScript might be modifying the page content, the page is queued for rendering by the Web Rendering Service (WRS).
- What is the WRS? It’s a service that uses a headless version of the Google Chrome browser to “paint” the page.
- Why does it do this? Its goal is not to admire the layout. Its purpose is to execute the JavaScript to discover content and links that were not present in the initial raw HTML. For modern frameworks (React, Angular, Vue), this step is essential to see the final content a user would see.
- The key takeaway: Rendering is a separate, secondary, and incredibly expensive step. It is not performed on every page during every crawl. It’s used when needed to ensure the completeness of the content for indexing. The bot fetches; the WRS renders. They are not the same thing.
- Indexing (The Librarian): Once the WRS has produced the final, “rendered” HTML (the DOM), this content is sent to Google’s indexer, named Caffeine. The indexer parses all the text, extracts links (and their anchor text), and notes structural elements like headings (<h1>, <h2>), semantic HTML (<nav>, <footer>), and other signals. This is where PageRank calculations happen, where content is analyzed by systems like BERT for semantic understanding, and where the page is stored for retrieval in search results.
The bot doesn’t assess the value of footer links by looking at the page’s design. The indexer assesses them by counting them, analyzing their anchor text, and using the global link graph (PageRank) to determine their weight. It understands a link is in a <footer> element because it sees the tag in the code, not because it visually identifies a block of links at the bottom of the rendered page.
Enter the LLM Bots: Fueling the Fire
The rise of Large Language Models (LLMs) has thrown gasoline on this fire. We now have bots like OpenAI’s GPTBot and Google’s own Google-Extended crawling the web. This has reinforced the generic “bot” and “robot” terminology, leading to further conflation.
People see that AI is now a huge part of Google and that AI bots are crawling the web, and they assume the two are directly linked in the way they imagine. They think the “AI” is happening during the crawl.
But these LLM bots are even simpler in their objective than search bots. Their sole purpose is to vacuum up massive quantities of text data tosynthesize. They are profoundly unconcerned with your CSS, JavaScript functionality, or Core Web Vitals. They are text extractors, plain and simple. Their existence has unfortunately made it easier for people to believe in a single, all-powerful “AI robot” that crawls, renders, judges, and indexes the web in one magical process.
The High Cost of Fantasy: A Catalogue of Over-Engineered Design
Believing in the design-savvy crawler isn’t just a harmless theoretical error. It leads to real-world development choices that actively harm SEO performance by prioritizing aesthetics perceived to impress a machine over the technical fundamentals that machines actually understand.
The web is littered with sites suffering from these delusions. Below is a table of common over-engineered tactics, the false belief that drives them, and the harsh SEO reality.
| Over-Engineered Tactic | The Developer’s (False) Belief | The SEO Reality & Negative Impact |
| Complex JavaScript Mega Menus | “The crawler will be impressed by this slick, dynamic navigation and will click through all the options like a user.” | Reality: Links hidden behind hovers or clicks within a complex JS widget may not be found in the initial HTML payload. Googlebot has to expend its crawl budget on rendering the page just to find your primary navigation.
Impact: Wasted crawl budget, potential for key pages to not be discovered or to be seen as less important, and poor accessibility. |
| Parallax Scrolling / “Scrollytelling” | “This immersive, cinematic experience will captivate the crawler and show it that we have a high-quality, modern site.” | Reality: Often implemented as a single URL where content fades in and out based on scroll position. The bot may only see the content present on the initial load. Without a robust implementation of the History API to create unique, indexable URLs for each “section,” the content is invisible to search.
Impact: Massive amounts of content are simply not indexed. The site appears thin or empty to Google. |
| Rendering All Text in a <canvas> Element | “We can create truly unique typography and visual effects that a design-aware crawler will surely reward.” | Reality: This is the SEO equivalent of printing out your website and mailing it to Google. To a bot, a <canvas> element is a black box, an image. The text inside is completely inaccessible unless you provide a full text fallback in the DOM (which developers often forget). <br><br> Impact: Zero keyword rankings, as Google sees no text content to index. |
| Excessive “Fade-In” Animations on Load | “The gentle fade-in of content elements creates a premium feel that the bot will interpret as a high-quality user experience.” | Reality: If content is set to opacity: 0 and visibility: hidden and only revealed after a CSS animation or JS timer completes, it can impact what Google’s WRS captures in its snapshot. More importantly, it can delay the Largest Contentful Paint (LCP), a key Core Web Vitals metric. <br><br> Impact: Poor CWV scores can negatively impact rankings. Content may be missed or its appearance delayed, affecting indexing. |
| Hiding Main Content in Click-to-Reveal Tabs/Accordions | “This organizes the content neatly and shows the crawler that we have a well-structured, user-friendly page.” | Reality: While Google has stated it now indexes this content with full weight (historically, it was devalued), it still requires an extra action (rendering and potential interaction). Furthermore, it sends a structural signal that this content is secondary to what is immediately visible on page load.
Impact: It can signal lower importance for the hidden content and creates an extra hoop for the rendering service to jump through. |
Searching for discussions around these topics reveals a clear pattern. Developer forums on Stack Overflow or Reddit are filled with questions like “How to make Googlebot wait for my animations?” or “Why isn’t Google indexing my React app content?” The underlying premise is almost always the same: they’ve built an experience for a human-like bot and are now trying to reverse-engineer technical soundness into it. Conversely, SEO forums are filled with experts explaining the concepts of crawl budget, server-side rendering (SSR), and DOM simplicity—trying to bridge the gap from the other side.
Stop trying to impress a phantom. The bot is not a user. It’s a glorified curl command on a mission. The rendering service is an expensive, overworked specialist called in when that mission gets complicated. And the indexer is a librarian that reads the code, not a critic that reviews the art.
