Building Your Own SEO Tools with AI
Why Google Urges Caution

Key takeaways

• The trigger: Google’s John Mueller wrote on Reddit that you can build your own SEO tools, but as long as you don’t know exactly what you’re doing, a maintained tool saves a lot of time.
• The core point: With AI, you can build a crawler, a program that fetches a website page by page, in about an hour. That still doesn’t give you a list of the issues you should actually fix.
• The risk: AI presents wrong results just as convincingly as right ones. If you don’t know the field, you won’t notice.
• My experience: AI is good at finding errors. Which of them matter, and what it can’t see at all, still comes down to expertise.

Contents

1. What John Mueller said
2. Why a crawler of your own is not an SEO audit
3. My test: AI checks my own website
4. Where home-built AI tools make sense
5. What you can do now
6. Frequently asked questions

AI now makes it easy to build your own software in a short time, including SEO tools. That’s tempting, because good SEO tools can easily cost several hundred euros a month. Still, John Mueller, Search Advocate at Google, urges caution. His reasoning is simple: building the tool is not the problem. Understanding what it tells you is.

What John Mueller said

A user in the Reddit forum r/TechSEO asked how to run an SEO audit without Screaming Frog. Screaming Frog is a well-known program that crawls websites and lists technical issues. Mueller replied there. In summary:

• Of course you can build your own SEO tools. But unless you know exactly what you’re doing, a working, documented and maintained tool saves a lot of time and effort.
• With basic Python skills you can build your own crawler, and AI tools have made that even easier.
• Having your own crawler doesn’t mean you have a ready-made list of technical issues to work on. Worse: you can’t look up anywhere what the results mean, and you can’t ask anyone for help.
• Some tools are inexpensive. If you do SEO professionally, the investment pays off.

AI adds a risk that Mueller doesn’t spell out: AI answers sound convincing even when they are wrong. If you don’t know SEO well, you will hardly spot those mistakes.

Why a crawler of your own is not an SEO audit

I agree with Mueller, for a practical reason. A crawler collects data: status codes, titles, redirects, links. That’s the easy part. An SEO audit only starts after that. Then the questions are:

• Is this redirect a mistake or intentional?
• Is this page set to noindex, meaning excluded from Google Search, on purpose?
• Does this issue really cost visitors, or is it cosmetic?
• What comes first? With 40 findings, the order matters more than the list.

A paid tool doesn’t have a ready answer to these questions either. But it explains every finding, there is documentation, and thousands of other users have seen the same warning before. With a home-built tool, you’re on your own. If it counts something wrong, nobody notices. That’s what Mueller means when he says you can’t look anything up.

There’s a second problem: a home-built tool only checks what you thought of while building it. What you don’t know about, you don’t test for.

My test: AI checks my own website

I use AI every day myself, including for technical checks. Today I had my own website checked by Codex, an AI tool from OpenAI that can read program code. The result fits Mueller’s warning well.

Codex returned eight findings, none of them serious. Some were real bugs I would probably only have noticed later. In a new online questionnaire, for example, someone who said they advertise on Instagram got tips for Google Ads. The AI found that well, because it reads the code line by line. Other findings were minor, such as redirects that pass through an extra step. Not important, but worth cleaning up.

More interesting is what Codex did not find. Anyone who opened my address without “www” was first sent to an unencrypted http address and only then to the correct one. That isn’t in the website’s code but in a setting at the hosting provider. So the AI simply couldn’t see it. It only showed up when I double-checked the live site.

My takeaway from the test: AI is a very good checker, but only of what you show it. Which findings matter, which can wait and where else to look was not decided by the AI. That was experience.

Where home-built AI tools make sense

I don’t want to talk anyone out of tinkering. For small, clearly defined tasks, your own AI-built tools are often faster than any paid tool. For example:

• checking a list of URLs for status codes
• pulling the titles and descriptions of all pages into a spreadsheet
• checking after a migration whether all old URLs redirect correctly

This works because you know the question and can judge the result yourself. It gets difficult when your own tool is supposed to replace judgment. A tool that reports “your website has 37 SEO errors” doesn’t tell you whether any of them is costing you customers. For more on what you can handle yourself and where help makes sense, read DIY SEO.

What you can do now

1. Ask the question first: Before you have a tool built, write down in one sentence what it should answer. Without a clear question, you get a long list with no priorities.
2. Spot-check by hand: Take five of the tool’s findings and look at the pages yourself. If two of them are wrong, don’t blindly trust the rest.
3. Check the live site: Code and live site are not the same. Open important URLs in your browser, including without “www” and with “http”.
4. Get a second opinion: For decisions that affect your rankings, such as deleting or redirecting many pages, it’s worth having someone look who knows such cases. I describe what a thorough check covers under Technical SEO.

Next step

You have a list of findings from an AI tool and don’t know which ones matter? Get in touch for a free consultation. We’ll go through the points together, and afterward you’ll know where to start.

Frequently asked questions

Can I run a complete SEO audit with ChatGPT or another AI?

Partly. AI can collect data, sort it and give hints. But it doesn’t know what is intentional on your website, and it is sometimes convincingly wrong. For assessment and priorities you need expertise, your own or someone else’s.

Is a paid SEO tool worth it for small businesses?

For a one-off check, usually not. The free Google Search Console or the free version of a crawler is often enough. If you work on your website regularly, a maintained tool saves time. John Mueller says the same.

What is a crawler?

A program that fetches a website the way a search engine does: page by page, following links. Along the way it records things like status codes, titles and redirects. What that data means, it doesn’t tell you.

Why doesn’t an AI find every error?

Because it only checks what it gets to see. If it reads the code, it doesn’t see settings at the hosting provider. If it fetches the pages, it doesn’t see what the code was supposed to do. Good checks therefore look at both.

Sources

1. John Mueller: reply in the r/TechSEO forum, Reddit, November 2026, reddit.com