GPT-6 Luna being half the price of GPT-5.6 Luna is a really big deal.
Here's GPT-6 Luna pelicans: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2F40d129fc140faca378b9c9f4f16c6ec2" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
And GPT-6 Sol: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2Fbe7ae25af2634b68bc34b7b7aaf02cb2" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
Scroll to the bottom for the GPT-6 Sol max one: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2Fbe7ae25af2634b68bc34b7b7aaf02cb2#response-5" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
For comparison, here are the pelicans I got for GPT-6 Astra: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2Ff789d2784fc6c5b870cc80f0b7cd9d01" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht... - I still like the Astra Max one best.
Here's a comparison grid showing all of the GPT-6 and GPT-5.6 pelicans at all effort levels: <a href="https://static.simonwillison.net/static/2026/gpt-6-and-5.6.html" rel="nofollow">https://static.simonwillison.net/static/2026/gpt-6-and-5.6.h...
The grid is actually really interesting, because it shows that the 5.6 family default to brighter colors than the 6 family.
Simon - I believe you've been doing this with a "one-shot" approach. Have you ever considered seeing what the results are with a few more prompts? Maybe 1,2,3 adjustments?
Something like the astra MAX is pretty darn good - but something is up with the right wing and the right foot (flipper?)
I bet each of these could be modified to be significantly better with 1 or 2 "rounds" of adjustments. (Others not so much).
Obviously, not as deterministic as your single prompt approach, but something I just thought of while thinking about the price (Because wow! For some of these I'd expect a usable SVG after that much).
simonw · · focus · HN ↗
Here's GPT-6 Luna pelicans: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2F40d129fc140faca378b9c9f4f16c6ec2" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
And GPT-6 Sol: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2Fbe7ae25af2634b68bc34b7b7aaf02cb2" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
Scroll to the bottom for the GPT-6 Sol max one: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2Fbe7ae25af2634b68bc34b7b7aaf02cb2#response-5" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
For comparison, here are the pelicans I got for GPT-6 Astra: <a href="https://tools.simonwillison.net/markdown-svg-renderer?url=https%3A%2F%2Fgist.github.com%2Fsimonw%2Ff789d2784fc6c5b870cc80f0b7cd9d01" rel="nofollow">https://tools.simonwillison.net/markdown-svg-renderer?url=ht... - I still like the Astra Max one best.
Here's a comparison grid showing all of the GPT-6 and GPT-5.6 pelicans at all effort levels: <a href="https://static.simonwillison.net/static/2026/gpt-6-and-5.6.html" rel="nofollow">https://static.simonwillison.net/static/2026/gpt-6-and-5.6.h...
The grid is actually really interesting, because it shows that the 5.6 family default to brighter colors than the 6 family.
NichoPaolucci · · focus · HN ↗
Something like the astra MAX is pretty darn good - but something is up with the right wing and the right foot (flipper?)
I bet each of these could be modified to be significantly better with 1 or 2 "rounds" of adjustments. (Others not so much).
Obviously, not as deterministic as your single prompt approach, but something I just thought of while thinking about the price (Because wow! For some of these I'd expect a usable SVG after that much).
simonw · · focus · HN ↗
1. Each model gets three chances, and then gets to pick the best according to its vision input
2. Models run in a loop where they can produce SVG, see it rendered, and then edit it further
I tried that loop last year and had disappointing results, but the models are a lot more effective this year.