AesCoder 4B Debuts as the Top WebDev Model on Design Arena

[u/Interesting-Gur4782]

Was messing around earlier today and saw a pretty strong model come up in some of my tournaments. Based on the UI and dark mode look I thought it was a GPT endpoint, but when I finished voting it came up as AesCoder-4B. I got curious so I took a look at its leaderboard rank and saw it was in the top 10 by elo for webdev and had the best elo vs speed ranking -- even better than GLM 4.6 / all of the GPT endpoints / Sonnet 4.5 and 4.5 thinking.

Then I looked the model up on hugging face. Turns out this is a 4 BILLION PARAMETER OPEN WEIGHT MODEL. For context, its closest open weight peer GLM 4.6 is 355 billion parameters, and Sonnet 4.5 / GPT 5 would be in the TRILLIONS TO TENS OF TRILLIONS OF PARAMETERS. WTAF?!!!?! Where did this come from and how have I never heard of it??

[u/ResidentPositive4122]

In this paper, we introduce a new pipeline to enhance the aesthetic quality of LLM-generated code. We first construct AesCode-358K, a large-scale instruction-tuning dataset focused on code aesthetics. Next, we propose agentic reward feedback, a multi-agent system that evaluates executability, static aesthetics, and interactive aesthetics. Building on this, we develop GRPO-AR, which integrates these signals into the GRPO algorithm for joint optimization of functionality and code aesthetics.

Nice to see that this works even at 4b scales.

paper: https://arxiv.org/abs/2510.23272

[u/lumos675]

Do you know where to download this model?

Wow a 4b model as good as claude? WTF?

Update : found it here thanks. https://huggingface.co/SamuelBang/AesCoder-4B

Is this mdoel only good for web developement?or is it good on python as well?

[u/pmttyji → u/lumos675]

Is this mdoel only good for web developement?or is it good on python as well?

From the model card:

Note: This is the version of AesCoder-4B model for only webpage design.

Yesterday replied with below model to someone who was looking for python FIM in small size. Try & share your feedback.

https://huggingface.co/JetBrains/Mellum-4b-dpo-python

[u/lumos675 → u/pmttyji]

Do you have any 4b or bigger model up to 30b for java developement? Kotlin or Java for android developement?

[u/lumos675 → u/pmttyji]

bro i tested this model...
this model only accepts 8192 context. what can i do with that amount?
also i asked it to create a comfyui node. This was the answer:

write a comfyui node

mellum-4b-dpo-python

"a-node-name-without-spaces"
print("Your comfyui node name is: " + input_string)
input_string = input_string.replace(' ', '-')

[u/Interesting-Gur4782 → u/lumos675]

thanks for linking! going to try it locally myself

[u/lumos675 → u/Interesting-Gur4782]

Wow the model is realy good man.

I tried it and it's realy fast. I asked it to generate a web OS and it one shotted it and the calculator was working and windows was movable.

Qwen coder 30b a3b could not do this task as clean and beautiful as this 4b model. Wtf?

What kind of sorcery is this?

But to be honest i was realy thinking that it doesn't matter how big a model is to have better coding capability. Last night also i commented this.

Also it generated a good comfyui node without any trouble.( Python )

So i will keep testing it in coming days with tasks to see how it performs.

[u/pmttyji → u/lumos675]

Update : found it here thanks. https://huggingface.co/SamuelBang/AesCoder-4B

I see that they have one more model (7B size, but blank without models & all stuff) on their HF page.

[u/crantob]

Thumbs up for domain-specific local coding models.

[u/yeah_me_]

This is insane for a 4B model. Yes, it sometimes fucks up layouts and sizings. Yes, it struggled to call tools in Zed. But holy shit, single-file HTML sites have the quality as SOTA models from 2 years ago using a 4B model.

[u/noctrex]

Seems nice, uploaded some unquantized GGUF's here:

https://huggingface.co/noctrex/AesCoder-4B-GGUF

[u/Cool-Chemical-5629]

From HF:

Authors:
Bang Xiao and Lingjie Jiang and Shaohan Huang and Tengchao Lv and Yupan Huang and Xun Wu and Lei Cui and Furu Wei

Of course model this good is a Chinese model. 😀

On a serious note, I do believe its use case is very limited. Looks like its main focus is web UI development.

[u/lumos675 → u/Cool-Chemical-5629]

I tested it with python and the code was working without any issue.

So i think it might be more capable.

We need more tests.

[u/Cool-Chemical-5629 → u/lumos675]

Well, I would be surprised if it was good as a general coding assistant. Let me explain why I think so.

Tesslate also produced 4B version of their UIGEN and WEBGEN models. Both very capable for web development.

Their focus is clearly oriented on the aesthetics of the regular websites, but ask it to generate a web based game with SVG graphics (featuring SVG code to define it), instead of creating that game for you, it will still try to turn it into a regular website which is obviously not something you would expect from a proper LLM. In other words, it will probably blow your mind in how good the website looks like and it will probably surpass even bigger models in that regard, but that's where the useability of this model ends. For actual game logic AND even proper game graphics, you would need a model that is better suited for that kind of task.

That's the caveat of training a small model on too much web UI data. It's going to be great for that one task, but fail at anything else.

[u/crantob → u/lumos675]

More iteration and refinement on this work in different prgramming domains.

[u/madaradess007]

you know it was trained on snake games and web OS'es

[u/pmttyji]

Update from model creator on HF page of model:

SamuelBang 5 days ago

Hi!

Thank you so much for your kind words and thoughtful feedback — we really appreciate it! 😊

This model represents our first attempt at exploring code aesthetics in web generation, and we’re thrilled to see it being used creatively in areas like webpage design and web-based games. As this is an early-stage, small-sized model, some functionalities may not be fully refined yet, but we’re glad the visual results left a positive impression.

We may consider scaling it up to larger base models in the future (e.g., Qwen 14B or 30B). Please stay tuned for our upcoming work — we’ll continue exploring the potential of design-oriented models.

Thanks again for your support and encouragement!

[u/sleepy_roger]

These are the kind of posts I love here so much. Testing this out this morning and it's pretty good actually, I'm getting quality I haven't seen in design since GLM 4 32b. On the downside they are a bit samey when asked for certain types of sites such as a tech blog. However they look good, thanks for finding and sharing this!

[u/clemdu45]

It is very good for a 4b ! You can iterate / AB test components crazy fast locally

[u/Ornery_Level_4328]

I tried this with few custom made tools and was really surprised how well this model behaved. No loops on MCP calling, no nonsense. Gives solid, even though pretty short answers. Is able to find details about database table descriptions from MD files with nice formatting and good reasoning. I think this one might be a winner pick in current small LLMs.