How Perplexirty Crawls and Ranks your content

The Great AI Search Engine Myth: Why Your Favorite LLM is a Glorified Google Wrapper

There’s a narrative taking hold in the tech world, a story whispered from tech blogs to venture capital pitch meetings. It’s the story of the “Google Killer,” the dawn of a new era where Artificial Intelligence has finally reinvented web search. At the center of this story are Large Language Models (LLMs) and their poster child, Perplexity AI, hailed as a revolutionary, independent search engine.

It’s a compelling story. It’s also a myth.

The single most important, and most misunderstood, concept in this new AI gold rush is this: Large Language Models are not search engines. They do not crawl the web. They do not index content. The idea that they are building a new, independent map of the internet to rival Google is a convenient fiction, one that serves to inflate valuations and obscure a much simpler, less revolutionary truth.

Today, we’re going to pull back the curtain. We’re going to dismantle this myth and show you what’s really happening under the hood. The magic you’re seeing isn’t the birth of a new search engine; it’s a clever, high-speed synthesis of the old one you’ve been using for decades.

The Bedrock of Search: What Google Actually Does

To understand what an LLM is not, you first have to appreciate the monumental task a true search engine performs. For over twenty-five years, companies like Google and Microsoft have been engaged in one of the most complex engineering challenges ever conceived: indexing the public web.

This process has two core components:

1. Crawling: This is the discovery phase. A search engine deploys an army of bots, often called “spiders,” that constantly traverse the internet. They start with a list of known pages and then follow every single hyperlink they find, discovering new pages, updated content, new websites, and dead links. Google’s crawlers are estimated to visit billions of pages every single day.
2. Indexing: Crawling is useless if you don’t store what you find. As the crawler gathers data, this information is processed, categorized, and stored in a colossal database called an index. This isn’t just a simple list of words; it’s a highly complex map that understands keywords, entities, concepts, the authority of pages, the freshness of content, and trillions of other signals. When you search Google, you aren’t searching the live internet; you are searching Google’s pre-built, meticulously organized copy of the internet.

This infrastructure is almost unimaginably vast. It requires a global network of custom-built data centers, hundreds of thousands of servers, and an investment of hundreds of billions of dollars over decades. This is the bedrock of web search. It is the non-negotiable price of admission, and LLMs haven’t paid it.

The Nature of the Beast: What an LLM Actually Is

So, if an LLM isn’t crawling and indexing, what is it doing? An LLM, at its core, is a language prediction model. Think of it as the most sophisticated autocomplete system ever created. It has been trained on a massive, but static, dataset—a snapshot of books, articles, and a huge chunk of the internet from a specific point in time.

Its “knowledge” is based on recognizing patterns in that training data. It knows that the words “President of the United States” are statistically likely to be followed by a name like “Joe Biden” or “Abraham Lincoln.” It does not have a live connection to the internet. It cannot, on its own, check today’s news, look up a stock price, or see that a new restaurant has opened down the street. It is a brilliant scholar locked in a library, able to synthesize and discuss only the books it has already read. Its knowledge has a cutoff date, and it gets staler every second.

The Illusion of Live Search: The “Query Fan Out” Trick

This brings us to the central illusion. If LLMs have no live knowledge, how do tools like Perplexity give you up-to-the-minute answers about current events? The answer is a process that can be called “search-augmented generation” or, more colloquially, a “query fan out.”

Here’s the step-by-step breakdown of what really happens when you type a question into Perplexity:

1. You input a Question/prompt: You type, “What were the key takeaways from the Federal Reserve meeting yesterday?”
2. The LLM Reformulates: The system uses an LLM to interpret your conversational query and break it down into several efficient, keyword-based search queries a traditional search engine would understand (e.g., “Federal Reserve meeting results yesterday,” “Jerome Powell press conference summary,” “FOMC interest rate decision”).
3. The API Call: Here is the critical step. Perplexity takes those keywords and sends them to a traditional search engine’s API—most commonly Google or Bing. It is not searching its own index; it is asking Google for a list of the top relevant web pages.
4. Information Ingestion: Perplexity receives a standard Search Engine Results Page (SERP) from Google’s API—a list of links and text snippets. It then programmatically “clicks” on the top 5-10 results and scrapes the text content from those pages.
5. LLM Synthesis: Finally, this scraped, up-to-the-minute text is bundled together and fed into an LLM (like GPT-4 or Claude) with a new prompt: “Based only on the following text, write a comprehensive answer to the user’s original question: ‘What were the key takeaways from the Federal Reserve meeting yesterday?'”

The LLM then performs its core function: summarizing and rephrasing existing text into a clean, conversational answer, dutifully adding citations that link back to the Google search results it was just fed.

Perplexity’s brilliance is not in search; it’s in the seamlessness of this five-step orchestration. It has built a masterful user interface on top of a synthesis process. It is a wrapper—an incredibly sophisticated and useful one—but a wrapper nonetheless. It is a meta-layer that uses the brute-force indexing power of Google and the language prowess of an LLM to generate a new kind of output.

Some will point out that Perplexity runs its own crawler, PerplexityBot. This is true, but it’s a red herring in the context of their current product. Building a web-scale index that can compete with Google is a decade-long, multi-billion-dollar project. Their current crawler is likely used for building a supplementary, long-term dataset, not for powering the real-time answers you get today. For that, it stands on the shoulders of giants.

This distinction isn’t just academic. It matters because it reveals an uncomfortable truth: we are not witnessing the decentralization of information, but its reconsolidation. If all AI “search” tools are simply putting a new face on Google’s index, we are creating an information monoculture, where the same set of results is simply repackaged, further cementing the power of the original incumbents.

So the next time you hear someone declare that LLMs are the new search engines, remember what’s happening behind the curtain. Appreciate the technology for what it is: a powerful new interface for language and synthesis. But don’t mistake a beautiful summary for the colossal, gritty, and expensive work of indexing the world’s information. That job still belongs to the old guard.