No, ChatGPT Can’t Do Image Alt Tagging!

I saw a post on LinkedIn saying ChatGPT can help you with writing the alt tags in your images.

But it smelled like influencer garbage.

There were a few suspect points. The influencer used this prompt:

Make a table and write an ALT tag for this list of pictures:

https://cdn.nba.com/headshots/nba/latest/1040x760/2544.png
https://cdn.nba.com/manage/2021/08/olajuwon-1920.jpg
https://cdn.nba.com/headshots/nba/latest/1040x760/893.png

First, the screenshot used ChatGPT 3.5, as noted by its green OpenAI logo. 3.5 does not have internet access.

I ran that exact prompt. And guess what?

Two out of three are correct but the last one is Michael Jordan. I don’t watch basketball but I’ve watched Space Jam.

“Professional Basketball Player Headshot” is a good description. It’s the most accurate alt tag you’ll get.

Shockingly, in the influencer’s screenshot, the last image is tagged as “Stephen Curry – NBA Player Headshot”.

In another generation, I also got a wrong answer. This ain’t Kobe Bryant.

Or Kevin Durant.

Suspicious?

I’m positing that the reason why ChatGPT 3.5 can write correct alt tags for the first two images is because they have some data that allows them to identify the image. Maybe they have the URL saved in their training data and a description to go along with it.

Am I wrong? Tell me why on LinkedIn.

Let’s test more images. I went to imgur to get some newer images in an attempt to have images that are newer than the training dates of GPTs.

Here’s the output. You’ll agree that it’s nonsense.

So my conclusion is …

1. Bad influencers just want to spread, like the influenza. Keep your social distance.
2. ChatGPT 3.5, using URLs, isn’t a viable way to get accurate tags. I mean, sometimes it’ll say this:

Translation: “Go do it yourself!”

ChatGPT 4 Can Alt Tag Images

I uploaded the four images above as JPEGs and asked ChatGPT to alt tag them. The results were much better.

Here are the images for reference, taken from a screenshot with ChatGPT 3.5’s output. You can immediately tell the difference in accuracy between 4 and 3.5.

I know ChatGPT 4 has internet access but I am unsure why it wouldn’t allow me to pull these images from the web.

Also, if you noticed, ChatGPT 4 won’t name some brands such as “Star Wars”, as you can see in the LEGO image above.

It also won’t name famous people.

Psst… the black background is accurate because transparent backgrounds in PNGs can sometimes be interpreted as a black background.

I tweaked the prompt because the output was too long and created this:

Make a table and write an ALT tag for the uploaded pictures. Maximum 140 characters. Do not exceed this 140 characters.

ChatGPT Can Help You Tag Photos, But Only If You Do It Right

The only method that you can reliably count on involves:

• Uploading your photos (no web browsing, no URL links)
• Asking ChatGPT to alt tag them
• Reviewing the output, because ChatGPT is opinionated and error-prone.