Testing Claude Sonnet 4.5 vs Opus 4.5

First of all, I really like AI. Second, Claude Opus 4.5 released today. Third, the new Claude Code for Desktop area in the Claude for Desktop app released today. Fourth, when I say today, I mean 11/24/2025 aka when I wrote this post.

Anyways let’s see how well both Claude Sonnet 4.5 and Claude Opus 4.5 create pixel art desktop apps. We will be using Claude Code with this prompt:

Create a pixel art app that must:
- Allow custom color picking
- Allow export as PNG
- Allow drawing with pixel art
- Must be a desktop app
Other than that, you are free to make it however you want, in whatever format you want, and with whatever other details you want. Feel free to add more features than that and keep going, you don't have to settle once you've made the minimum viable product.

Alright, let’s see how they do! Downloads below!

Sonnet 4.5

At one point, it wanted to npm install so I denied it with "We don't need to install it right now, just make sure there is a requirements file or the like (I assume provided in package.json)." After a bit more pondering and crafting, it made an app.

The app is built on electron and can be built on your system with npm install and npm start though you can likely read the same from the README.md.

The app was feature-rich with 7 tools and was a nice sleek design. I do admit it half-cheated by making a web app packaged as a desktop app. Only 2 flaws I saw - the grid disappeared when using tools like circle or line, and it tried to use its own SVGs for icons (AI-generated SVGs are bad. Maybe I’ll train LLaMA to be good at SVGs sometime. Or Phi. (Both small local AI models).

I made this to test:

Here's the project download (folder zip):

Don't ask why I have way too many downloads, but here’s some more:

macOS Universal .dmg (you don’t need to drag to applications)

Windows Portable .exe

Alright, this was really cool, but it’s not even the...

Opus 4.5

...best model out of the two. Exactly what it says. Opus 4.5 is the opus.

Same prompt, let’s go.

Well it glitched out with $PATH issues and local machine stuff and Homebrew so I guess I’m using cloud. Whatevs. Except... that didn’t work and wouldn’t connect so I’m trying it again locally. Now that’s ALSO stalling and I want to bang my head into a wall. (JK). So time to boot up my terminal and use the terminal one. And then I had to outdate to Node 24 not Node 25 to fix Claude Code... but then issues with $PATH and node and brew so then I used the cloud version but that didn’t work and...

Well, I fixed it. I also used "Hey there Claude!" before the prompt to make it generate new responses and not reuse. Anyway... it also didn’t try to npm init -y so well now it won’t crash on that like it was before with the $PATH stuff and versioning.

Anyway sorry for rambling about annoying package managers.

Also, again, I had to "I'll test it, thank you." to Claude 4.5 Opus - but let’s see the end result!

And OH MY GOSH, Opus says this is way more full featured than Sonnet’s one.

Wow.

This is much better.

Except the grid didn’t work, but I fixed that within 1 extra prompt. It even had the preset palettes and I made an image in the PICO-8 palette. I even scaled it up using Affinity so it’s easier to see.

And here’s the downloads:

Project ZIP:

macOS Universal .dmg:

Windows Portable .exe:

Final Words

Well this was really fun - and you can even try the apps yourself! Opus definitely made a better app. Ok bye!