Improving GPT‑5.6 Sol in ChatGPT, expanding GPT‑5.6 Luna access for free users

(openai.com)

Comments

firasd 6 August 2026
I think it’s a misread to think the default ChatGPT model switching to GPT 5.6 Luna is some sort of desperation move. Keep in mind that Claude .ai never had this extreme stratification between the frontier models and the free tier (Sonnet is available to free users with rate limits).

So 5.6 Luna is just their next version of what they used to call 5.5 instant tier

And 5.x instant models were never much to write home about anyway so the default ChatGPT free model hasn’t been particularly distinctive since 4o

ilaksh 6 August 2026
> Our mission is to ensure that artificial general intelligence benefits all of humanity. We’re introducing updates to ChatGPT that improve everyday conversations while expanding access for Free users.

This clearly implies that they believe ChatGPT models are AGI and are now willing to say it out loud.

Which I think is a fair interpretation of the term. They are general purpose intelligence in that you can get help from them about almost anything. They are not like narrow single purpose AI models.

I don't think we need that term to mean "can completely emulate a human" or "can do every task any human on earth can do as well as them".

It also needs to be differentiated from ASI with godlike powers many times greater than human.

aryehof 7 August 2026
For me on a paid plan, the effort indicator was hidden and the model was 5.5 instant. I had to press the + button to select “think harder” before the dial that allowed Sol medium or high to be selected to show.

It made me wonder how many paid subscribers realize they are using the same 5.5 instant model as free users by default. A dark pattern or oversight?

heaney-555 6 August 2026
Giving free ChatGPT users access to reasoning (the 'Think' toggle) will have a broader impact on the world than every new paid model and coding agent combined.
saithound 6 August 2026
While their math results are impressive, vibe coding their own web UIs with their subpar design models is really going to backfire if their plan is to attract new users with better free model offerings.

The Aug 6 update has forced the entry box to auto-format Markdown in an attempt to imitate Claude. The implementation is buggy and even simple copy-and-paste has gone entirely haywire. They also forgot to leave a switch to turn the confounded autoformatting thing off.

Chat mode in general is currently crawling with more UX bugs than a porch screen in summer.

colingauvin 6 August 2026
They must really be feeling the commoditization pressure. I'm not sure what the way out of this is, ChatGPT and Claude are still good products, but they are not necessarily premium products anymore.

I expect a few things to happen in the next year:

1) Exclusive MCP server deals/API integrations

2) Significant switch to B2B marketing, even moreso than we've seen before, with API interfaces being paid and chat-client interfaces becoming more and more free, perhaps just with limits more on integrations or data visualization/analysis

3) US restrictions on B2B contracts with non-US hosted models that do any sort of contracting with the government

Obviously there's a bunch of stuff I'm not foreseeing. But it really does feel like the bottom of the market is collapsing into free. I assume OpenAI and Anthropic think their next generation of models will restore their halo tier status and that the cash burn is justified to just get there, but this has to really mess up IPO plans.

kingstnap 6 August 2026
Its always fun to try to read between the lines here to speculate why they are doing this.

Maybe Luna efficiency gain was actually significant enough that putting all the free users and giving them super generous limits makes sense.

They might be doing this to improve the messaging of AI among causal users since right now there is a huge amount of datacenter backlash in the US due to AI grievances.

Maybe they have too much excess capacity or they really want to juice token numbers and market share on their dashboards for marketing.

I also wonder if being given access to an actually a decent model like luna with actual thinking budget instead of brainless "instant" modes will start to make causal users understand the real capabilities of these models.

tosh 6 August 2026
free unlimited luna is a pretty badass move

luna is very good

simonw 6 August 2026
Nothing in the ChatGPT model release notes yet: https://help.openai.com/en/articles/9624314-model-release-no...

(This is a subtle nudge at anyone from OpenAI who reads this to make sure they get updated.)

OpenAI have a model called "chat-latest" - I wonder if that's running this new model yet: https://developers.openai.com/api/docs/models/chat-latest

It's described as "points to the latest Instant model currently used in ChatGPT" - so presumably that's "GPT-5.6 Instant" in the app.

1saadcodes 7 August 2026
I dont get why they'd make this available to free users when they're probably dealing with compute constraints considering their competition with the Chinese models. Giving a more capable model to a huge free user base looks like an expensive choice to me
ElijahLynn 6 August 2026
I can't wait to never see a reasoning button ever again. Why do I have to reason about what reasoning level to use?
try-working 7 August 2026
What's even more noticable is that Anthropic still hasn't responded to the Kimi K3 release or the DeepSeek release.
kaszanka 7 August 2026
> Because this version of GPT‑5.6 Sol is optimized for everyday chats, it will only be available in the Chat experience in ChatGPT. The version of GPT‑5.6 Sol that powers Work and Codex is not changing as part of this release.

Hm, does this mean that 5.6 Pro in ChatGPT web is somehow different/not as good now? I found it really good for code review (upload your repo and patch and off it goes).

kgeist 6 August 2026
>avoid extra detail when it does not help

I wonder if they actually do it to optimize inference. I maintain a corporate AI server and one of the tricks to reduce the load was to modify the system prompt to be as terse as possible so the average response completes faster and requests queue up less often.

Gareth321 22 hours ago
My cynical read on this is that they're going to allow Sol on higher modes to downgrade its mode depending on the question or task.
lilytweed 7 August 2026
This post makes it sound like paid users should be getting a 5.6 Nonthinking as the Instant option. Still looks like 5.5 Instant to me?
itsmeduncan 17 hours ago
How long can OpenAI (and Anthropic) incentivize, and keep costs artificially down for tokens to depress investment in private/offline LLMs? It's interesting to watch the cost curves, and burn to see where it stops being venture subsidizes, and the frontier open-weight models become as good.
sunaookami 6 August 2026
This is actually a downgrade for free users since currently it uses GPT-5.5 for a few messages before it drops you down to GPT-5.5-mini. Now it always uses a model worse than Mini (Luna is nano-equivalent, "It roughly corresponds to the nano model tier used in earlier GPT-5 families." https://developers.openai.com/api/docs/models/gpt-5.6-luna ). I guess it's a bit better with Thinking though. They should use Terra for a few messages first before dropping down to Luna. And image inputs are still limited.
Razengan 19 hours ago
> Because this version of GPT‑5.6 Sol is optimized for everyday chats, it will only be available in the Chat experience in ChatGPT. The version of GPT‑5.6 Sol that powers Work and Codex is not changing as part of this release.

So same name, and no indication of which "version" you're using except whether you're in "Chat" or "Work"? Why make it so confusing?

roytam87 7 August 2026
OpenAI should be more transparent to (free) users about Data Analysis quota and Chat with attachment quota.
OsamaJaber 6 August 2026
Expanding free access is mostly an inference cost

Serving cheaply at that scale means routing, batching, and cache hits, not a better model :D

Ejkretlow21 6 hours ago
How I can open GPT-5.6 Luna
nc55g3g 23 hours ago
free users get unlimited text chats with Luna AND a Think button now? That's a massive upgrade.
Squarex 6 August 2026
Why pay for ChatGPT Go then?
applfanboysbgon 6 August 2026
> Our mission is to ensure that artificial general intelligence benefits all of humanity. We’re introducing updates to ChatGPT that improve everyday conversations while expanding access for Free users.

My mission is world conquest. I'm writing a comment on an HN thread.

No, those two clauses have no relation whatsoever. I just felt like saying the first sentence because it sounded cool.

ignoramous 6 August 2026

  Every week, 1 billion people turn to ChatGPT for everything from quick questions and web searches to planning, research, advice, and complex decisions.
Guess, Google's AI Mode is chipping away at their consumers (I know I haven't used Chat in a long, long while for 'quick questions and web searches' after OpenAI did away with "think" which I always use). The money-minting office & coding market Anthropic has cornered is hyper-competitive at both the frontier & low-cost ends. OpenAI is reactive [0] and seems right up against it, despite the strength of its excellent models.

[0] Won't put it past OpenAI (and/or Google) to open weight larger models!

johnnyApplePRNG 7 August 2026
Excellent.

Yes, please give free users more access and leave paying codex users in the dust.

Wise plan, Sam.

simianwords 6 August 2026
Does 5.6 Sol finally have an "instant" form? Is that the change?
jauntywundrkind 6 August 2026
At first I thought the Sol updates was perhaps trying to help with some complaints of Sol burning through tokens, complaints that have prompted some new data points on https://codex-resets.com/ .

But seeing the graphic with the visual weather report: that makes me think that is not the goal at all. :)

aniceperson 6 August 2026
a m-dash in the title? whoa things are degrading fast
iJohnDoe 7 August 2026
> For Plus and Pro users, we’re updating GPT‑5.6 Sol in Chat to be more reliable with facts and provide more focused answers.

I was not impressed with 5.6 and this hits exactly why.

Also, this instant, medium, and high slider situation we now have everywhere is batshit crazy. It’s a major step back in technology.

I’ll put money on the table there will be a surprise in revenue because users have no clue what to choose, so they are constantly choosing high because they don’t want to risk getting inaccurate answers. If this was intentional by the dark patterns department, then brilliant. However, I’m guessing Anthropic and OpenAI are struggling to know how to deploy their models.

Also, the models were already amazing. They need to slow down and do a model release once a year and only do extremely minor iterations instead. Some amazing things are accomplished, but how people actually want to utilize the models gets screwed up every time in the process.

porridgeraisin 6 August 2026
I dont pay for a chatgpt subscription, but sometimes I did use the web app for throwaway questions. GPT 5.5 Instant or whatever it was that they had was absolutely horrendous. Never answered a question straight and was pedantic in a way even a redditor wouldn't be. So I dropped it and just opened my paid coding agent for everything. Grok.com is quite good now with grok 4.5 though and I find myself using that often. Hopefully luna will be similar.