I’ve used vision-enabled LLMs before to identify types of tools, bike parts, or PC components with mixed results, but the net result was usually positive. At the least, I became armed with some of the terminology and knew what to look up on Google. The recent releases of Gemini 3 Pro ("The frontier of vision AI"), GPT-5 ("can reason more accurately over images and other non-text inputs") and Claude Opus 4.5 ("better vision, reasoning, […] and it is state-of-the-art in many domains") have made me curious to test the much hyped visual reasoning capabilities. Plus, they are touted to have PhD- or expert-level intelligence. Can an AI PhD help me change a hinge?

Mission (im)possible

I set out with a simple request: “Identify this type of hinge and find out where it can be bought in Czechia,” accompanied by the following picture:

Now, a small aside about hinges — the little I know. I promise it won’t be long, it can be explained in 30 seconds.

This is a hinge with a cup:

And this, my friends, is a type of hinge that does not use a cup, but is mounted directly to the face frame of the cabinet:

You can tell them apart very easily - I actually think 99% of you could now tell them apart without any issues. You can probably also tell that the hinge from my original picture is very clearly the latter one, as there is no place to mount the cup to in the cabinet face frame.

Our PhD-level expert LLM friends? Not so much.

Getting unhinged

Let’s start with Gemini. Even though I prompted it in English, it started thinking and responding in Czech, so I can’t quote it verbatim, but here’s a faithful translation from Google Translate:

The specific type in the photo appears to be: A cup hinge with a cup diameter of 35mm (this is the standard size, but it’s a good idea to check).

OK, that’s clearly wrong.

Let’s move on to Claude Opus 4.5, with excellent visual reasoning:

This is a Hettich concealed cabinet hinge (also called a European-style or cup hinge).

Not really! But wait, Claude is searching the web, maybe it can recover:

Based on my search, this is a Hettich Intermat concealed cabinet hinge (also known as a “miskový závěs” or cup hinge in Czech). It features a 35mm cup diameter and includes a clip-on mounting plate for easy installation.

Not quite either.

Maybe ChatGPT with GPT-5 will save the day?

Based on your photo, this appears to be a “European-style concealed cabinet hinge” — but specifically a variant that is face-frame / surface-mounted rather than the hidden “cup-in-door” type often used in frameless cabinets.

Alright, that’s much better! It seems that GPT-5 can reason more accurately over images. So what is its recommendation?

My Recommendation
Given your photo and situation, I’d start by ordering a clip-on concealed hinge for face-frame cabinets with a 35 mm cup — either basic or soft-close depending on whether you care about silent closing. That has the highest chance of matching the old hinge and mounting method.

Somehow, in the stream of tips and examples, GPT-5 convinced itself that this was after all a hinge with a cup, and ended up giving me the wrong recommendation.

I honestly do not know why all the models faceplanted so badly. It does seem that my type of hinges is relatively rare, but at least GPT-5 identified it correctly at first.

Just ask a real expert

Turns out, the AI labs aren’t optimizing for mundane DIY realities, and so you’d be better off asking literally anyone at your local hardware store or DIY shop. Even the SOTA LLMs are not there in terms of giving you reliable information for this category of problems. They fell short of even identifying my hinge, much less finding a site where I could buy a replacement.

The smallest of wins

There is a silver lining. When I confronted the LLMs with the fact that the hinge in the picture clearly does not have a cup, all three recovered and provided some genuinely useful information. They helped me nail down the terminology, and pointed me toward several e-shops I could browse to look for what I needed.

However, none of them were able to identify a specific product I could actually order. And perhaps more importantly, they only became helpful after I called them out on their mistakes. If I had trusted the initial responses (or if this had been a topic I knew even less about), I could easily have ended up ordering the wrong part.

An assistant you have to constantly fact-check and correct is of questionable value. For now, these expensive statistical behemoths remain more useful as a second opinion than a first resort for this type of problems.