I created an AI to objectively grade coins. Give it a try!

Ever since Compugrade tried [and failed] to use Artificial Intelligence back in 1991, coin collectors have wondered if we could use AI to accurately grade and identify coins. So I thought I would give my hand a try!

I created Numi, a fine-tuned version of ChatGPT4 specifically made to provide objective grading estimates and coin identification. [Works on both mobile and desktop]

You can upload up to 10 photos of a coin and the AI will run a combined analysis. Below are some info you will get back details such as:

• Short Description
• Coin Type
• Year
• Mint Mark
• Estimated Grade

Example Results here and here

What's cool is that you can continue the conversation with the AI to learn more about your coin.

• Want to know who designed the coin?
• Want to know why a certain symbol was used?
• Just follow up and ask!

Caveats

• You will need to have a ChatGPT Plus account
  
• This is an alpha build!
  
• I recommend you use wifi as uploading images will be faster
• OpenAI's servers are under heavy load lately, so responses may be currently slower
• The model isn't perfect, but it is quickly improving

Features Under Consideration

• eBay integration to see recent sold prices based on the estimated grade

This app is in the alpha stage. I made this app because I wanted to help the coin community out. I know a lot of people are looking for help with grading coins.

Looking for feedback and thoughts. Have fun finding ways to break it!


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Mods, please let me know if I should take this down or edit this post! This is a personal project and I have no way of making money off this. My goal is to see if I can make something to give back to the hobby that has given me so much.

 

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Here is an example video demo for those who do not have acccess to ChatGPT Plus

 

It's a bummer that OpenAI puts these models behind their paid subscription But here's a video demo of the app in case you want to see what it looks like

 

In case folks can't access the app or want to see a video

Title

Response Part 1

Response Part 2

 

Here are some examples of coins I've just tested on!

Jefferson Nickel - 1980 S Proof

• AI Grade Given: PR 67
• Photos Used
• Full AI Response
  

Lincoln Wheat Cent - 1948 D

• AI Grade Given: VF 20 - VF 25
• Photos Used
• Full AI Response
  

Mexico One Peso - 1971

• AI Grade Given: VF 20
• Photos Used
• Full AI Response
  

$5 Gold Liberty Head - 1880

• AI Grade Given: AU 55 - AU 58
• Photos Used
• Full AI Response
  

 

Update [11/13/2023]

I did a complete rework on Numi's internal logic and the results are looking significantly better. The model is now on v1.26 Alpha.

My current goal is to fine-tune the model so that grades are at most two grades off consistently. Eventually, this will move down to one grade off, then right on the money.

The model is exceptional at identifying high-grade Proof Coins. Here are the results for a Proof 69 Lincoln Memorial Cent - 2005 S


The model is getting within two grades in the mint state range. Here are the results for a MS-65 Lincoln Wheat Cent - 1938 D


The model is somewhat struggling in the AU range. But it's a lot closer than before. Here are the results for a AU-55 Liberty Head Eagle - 1868 S


The sweet spot for accuracy appears to be around 6-8 pictures of a coin.

I would love more help from the community with photos. Especially photos of coins that are from Poor (P) - Extremely Fine (XF)

 

Numi v1.27 alpha is now live!


Video Demo

Changes include

• Fine-tuned grading criteria to align more closely with third-party grading standards
• Changed response format to be more clear and concise
• Added Numista integration back in after fixing prior deployment issues

Users can now follow up on their conversation and ask Numi for additional facts about their coins such as:

• Mintage figures
• Coin values
• Coin details such as composition, diameter, weight, etc
• Info is pulled from Numista's database

Feel free to share any photos you'd like tested! I will post the results here

 

Congratulations. I think Numi is already doing a better job than the TPGS sometimes ;-)

 

Thanks for the kind words!

In some news...

v1.28 Update [11/17/2023]

Numi can now identify and grade ancient coins! Numi also now has a website domain! AskNumi.com

Better Numista database integration has been implemented. Users will now automatically get a link to the Numista page of their ancient coin, as well as be able to converse with Numi with more details.

Check out this live demo of Numi analyzing a 2000-year-old Denarius of Julius Caesar

Coin photos used

 

This is super cool, it's a bummer that ChatGBT plus is $20/mo. I might still do it for a month just to try this out, or wait til I have a whole bunch I want to grade.

Great work!

 

I'm guessing the TPGs won't like this.

 

The problem was that collectors didn't like objective and consistent computer-generated grades. They're happier, and spend more money on grading, when there's wiggle room -- it lets them profit from a coin that gets a surprisingly high grade, cherry-pick coins that are under-graded, and complain and finger-point either way. And then there are the stickers.

 

Yep, that's it...that's the reason. HAR is the future of collecting hobbies.

(PS: Good Luck with that)

 

For those of us that just want an easy, reliable way to get a reasonable estimate of grade, this is great. I don't do enough grading to be nearly accurate and then I might not do it for a while and have to "re-learn" what I'm looking for. It's not a replacement for TPG's in my mind although it could be to some extent.

 

I'm guessing the TPGs will absolutely adore this. It will generate an increase in business.

 

OK. Somebody has to state the obvious: this latest better mousetrap can not replace, in any manner, the human ability to grade a coin, to the extent that it is "objective". It is not. It never will be. Let me know when the AI can undergo a complete physical Ophthalmology exam and pass...color, depth, angle, pressure, distance, clarity, focus and specific focal point, etc.

 

I don't think anyone's saying it is or should replace the human factor UNLESS, that's what the market asks for. The fact that you can have a coin graded, break it out of the slab and have it graded again and it comes back different is proof of some subjectivity and proof of it being an "art".

AI can't create, it can only mimic. That being said, the fact that it can give a reasonably estimate of grade for the average joe collector like me is really cool.

I can't imagine this being used as a way to increase value of a coin though like happens when you have something graded by a TPG.

Just my $0.02

 

There are tasks AI can perform based on purely objective criteria that can deliver and serve as a valued resource to the numismatic community.

 

OR: It is the ability and experience of the Grader or lack thereof. I appreciate your assumptions, though, concerning the Art.