# ChatGPT has been silently routing Pro to mini for several months

> Source: <https://articles.fmt.kr/2026-07/oai>
> Published: 2026-07-31 06:07:05+00:00

# ChatGPT has been quietly downgrading Pro model into mini. No response.

## TL;DR

Using $200/month OpenAI's ChatGPT Pro(not lite), ChatGPT
has an issue where some Pro model sessions responded
like a mini model, or were routed into one, even when
Pro was selected in model picker. This is not normal,
never been documented, and has no visual cue whether
it's affected or not. My finding relies on analyzing
"frozen/static" chat metadata content
(`resolved_model_slug`

) rather than
potentially hallucinated model outputs or chat
responses.

I contacted support for two months[[img1]](#fnimg1)
but received only general/simple responses. Users paying
for the $200 plan expect research-grade intelligence,
not a same model offered to unpaid users. I publicly ask
OpenAI to explain this issue.

This happened next day after I subscribed to the
$200/month ChatGPT Pro plan[[1]](#fn1). While working as usual, the responses felt different.
I can understand OpenAI's model performance can be
inconsistent, but this change was too extreme to ignore.

The model's outputs fell far short of an expert or researcher quality, with the reasoning and thinking time significantly faster than normal (by dozens of times). Consequently, the performance was significantly below what is typically expected from the Pro model.

After noticing this, I asked, "What model are you?" It identified itself as a completely different model: "GPT-5 mini."

At first, I thought this was a model hallucination. Since there was no technical report for the Pro model, I thought its internal system might use mini models in some cases.

However, my suspicion increased after comparing different clients logged into the same account. Some clients that had remained logged in for a long time(still not exact, some clients were affected too) still behaved as expected from the Pro model. New logins and other clients showed invalid behavior. This must not simply a response varied with prompt complexity (like simple prompt goes to a simpler model). Both the web and Android clients were affected just in case.

The affected Pro sessions showed the following behavior:

- The Thinking UI did not appear, or reasoning finished almost instantly. I never saw text such as "Thought for ...s" in the suspected chats.
- The model always identified itself as mini when asked.
- I haven't reached any Pro model usage limit. When the Pro quota is exhausted, the ChatGPT UI disables the Pro option. It did not happen here at that moment.

I then investigated ChatGPT data exports and backend
network responses. Based on an early reply from customer
support, every chat in which the assistant identified
itself as GPT-5 mini contained `i-cot`

in the
`resolved_model_slug`

metadata property.
About a month later, another colleague researcher
reported a similar case. In that case, that property was
set to `gpt-5-5-mini`

.

While investigating that report, I also found a growing
number of similar issue reports on social media
recently[[reports]](#fnreports). Thus I decided to write about this issue.

Customer support made this issue even more frustrating.
I contacted support for about two months[[img1]](#fnimg1). The replies focused on general explanations, such as
model hallucinations or clearing the browser cache. I
never received any explainer, actual investigation
results, or clear solution. Attempts to contact relevant
OpenAI employees through X also received no response[[img2]](#fnimg2).

What I consider most important about this issue is
**transparency**. People pay $200 per month
not only for Codex, but also for research-grade
reasoning. Yet this behavior continued without any clear
notice in the UI or by email. There was no visible
indication/cue that something had changed. The issue
might not be limited to Pro users; Pro Lite and Business
accounts have fewer quotas. Users have no reliable way
to confirm whether they are receiving the service they
paid for. I was affected for several days. For that
period, the money was effectively wasted away.

AI products are no longer toys nowadays. They are
becoming essential tools for research, development,
writing, analysis, and decision-making. Users of
expensive services expect more than better answers; they
also expect predictable service like usual. When a
model's behavior suddenly changes and performance
becomes worse, the issue is no longer just performance.
It becomes a matter of **trust**.

I am not claiming that these observations prove every
part of my point.
**However, OpenAI has provided no explanation at
all.**

Users have every right to question whether they are receiving the service they paid for. When a provider stays silent or repeats useless answers, users lose trust in that provider.

I'm not asking OpenAI to disclose confidential internal
information. If this was a bug, respond that it was a
bug. If it was part of an abuse-prevention or rate-limit
policy, explain that effectively. If fallback routing
exists, explain when it occurs, address how it appears
in the UI, and explain what level of service is
guaranteed to paying users.
__Customer support never gave me any information
about any of this.__

Since
__this article is solely focused for
scientists/researchers/developers__, I still have a lot of stories to talk about. So I
might publish more articles when they do not address
this. Thank you to everyone who read this long and low
effort post.

## About Me

Computer engineering undergraduate student in South Korea. I have some LLM-like knowledge through discussions with NLP doctoral student, AI (mostly vision, but work for all domains) researcher who studied neuroscience on their own, and industry professionals. I do research on computer graphics, desktop Linux, and software engineering.

## How to Check Whether You Were Affected

The following ChatGPT shared chat sample links are available:

-
Normal/Expected behavior:
[https://chatgpt.com/share/6a604011-8db0-83e8-b3bb-9399a4460919](https://chatgpt.com/share/6a604011-8db0-83e8-b3bb-9399a4460919) -
5.6 Pro → 5-5-mini:
[https://chatgpt.com/share/6a616b12-d9b8-83ee-b1e0-acb29487fe45](https://chatgpt.com/share/6a616b12-d9b8-83ee-b1e0-acb29487fe45) -
5.5 Pro → i-cot:
[https://chatgpt.com/share/6a603bf3-0590-83ee-9f56-6d8b573d43da](https://chatgpt.com/share/6a603bf3-0590-83ee-9f56-6d8b573d43da)

At the time of writing, there are two objective ways to check:

- For chats you own, inspect the backend data in JSON via DevTools. If the chat was shared by someone else, fork it first. You will own that fork.
- Inspect the server-side rendered/injected data of a shared chat. ChatGPT injects the shared-chat data (frontend state) into the HTML. This method is more complex because the data is not provided as normal JSON, but it's a reliable way to retrieve it when the first method is unavailable.

In both cases, check the prop value near
`resolved_model_slug`

. Expects
`i-cot`

or `gpt-5-5-mini`

or
similar. The first method is strongly recommended. The
only advantage of the second method is that it does not
require login.

While it was possible before, requesting a data dump
export and inspecting
`resolved_model_slug`

is unavailable now. The
property seems to have been removed from exports
recently. A comparison is available in
[
this GitHub Gist link ](https://gist.github.com/ilsubyeega/c76617cd97a071a4ef4dab81f2d0cc76).

[[1]](#r1)
ChatGPT Plan | Pro. https://chatgpt.com/plans/pro/
visited 2026-07-30 (archived https://archive.md/H0nR2)

[[reports]](#rreports)

Disclaimer: Some portion of texts are not exact; some may truncated, machine-translated etc.

@paulscu1 (06-14): Just tried OpenAI’s web UI, I’m
shocked at just how bad the model routing is. I’m
paying $100 a month, and I can’t get more than one
reliable response from 5.5 pro before I start
getting routed to like 5.3 mini. It’s absurd product
design, I will pay more, just please please fix this
it doesn’t work
[X Post](https://x.com/paulscu1/status/2065886816238985490)

@Mortid_X (06-18): ChatGpt Pro extended 5.5 >
GPT-5.3-mini model. This is some kind of bug. On my
phone, everything works fine for me. I hope the
@OpenAI team fixes this bug. Watch the video for
proof: [video]
[X Post](https://x.com/Mortid_X/status/2067343110024085958)

@ludicrouslytrue (07-21): My web chat silently falls
back to 5.5 mini? I'm on the 20x Pro plan
@thsottiaux I thought codex and web limits weren't
shared, oh well. [video]
[X Post](https://x.com/ludicrouslytrue/status/2079532482928718203)

@sizumita (07-23): Why is it a 5.5-mini when it's a
Pro model?
[X Post](https://x.com/sizumita/status/2080269517176144169)

@_machi47 (07-24): across all of my GPT chats on the
Pro plan, when using GPT 5.6 Sol Pro, it routes to
GPT 5.5 mini. What is happening @thsottiaux ???? no
notices of degredation on the app itself. shows pro
level, but does not reason at all, jus instantly
spews garbage?[X Post](https://x.com/_machi47/status/2080394309715849434)

@q8jx_ (07-24): does your gpt 5.6 pro say it's gpt
5.5 mini too?
[X Post](https://x.com/q8jx_/status/2080417495765184514)

@RealWilliamHsu (07-24): You guys doing great but
ChatGPT with 5.6 Pro returned replies using GPT
5.5-mini, how's that a genuine reply to the users??
[X Post](https://x.com/RealWilliamHsu/status/2080469030499172453)

@kumataro_x (07-26): @OpenAI Support rejected my
refund request, saying it could not confirm that my
Pro requests were handled by GPT-5.5 mini. I now
have structured data returned by ChatGPT's own web
backend showing exactly why this requires an
engineering review. I selected Pro. The conversation
data shows: `default_model_slug: gpt-5-6-pro` But
two separate requests show: `resolved_model_slug:
gpt-5-5-mini` This is machine-readable metadata—not
a guess based on response speed or AI
self-identification. I obtained the JSON directly
from the response payload in my browser's DevTools
Network panel while loading the original ChatGPT
conversation. The conversation ID in the page URL
exactly matches the JSON. I also preserved the
original file and its SHA-256 hash. OpenAI's Help
Center says Pro is powered by GPT-5.6 Sol Pro. It
documents GPT-5.5 Instant mini as an Instant-limit
fallback—not as a fallback for selected Pro
requests. @OpenAI, please explain what
`resolved_model_slug` means and check the actual
serving model for my two request IDs. If Pro served
them, why did your backend return mini? If mini
served them, acknowledge the routing issue and
reconsider the refund.
[X Post](https://x.com/kumataro_x/status/2081060343955296414)

@whatfordinner12 (07-28): I pay $100/month for
ChatGPT Pro. The UI showed GPT-5.6 Pro. Pro quota
was charged. But the request was routed to
GPT-5.5-mini. But after I submitted screenshots,
chat links, and quota evidence, Support twice
dismissed it as “AI hallucination.” (1/5)
[X Post](https://x.com/whatfordinner12/status/2082056790091743508)

@TuringMeme (07-28): I’m a ChatGPT Pro user. Today I
noticed that selecting GPT-5.5 Pro automatically
switched my conversations to GPT-5.5 Mini. Support
explained that Mini is the fallback after reaching
the Pro usage limit. I understand having a fallback
model, but the problem is: the quality difference is
obvious, and there is no clear indication of when
Pro access will be restored. Please show the limit
status and reset time. Transparency matters for Pro
users.
[X Post](https://x.com/TuringMeme/statu</p>s/2082103025964023906)

@zhihe_md (07-29): I am extremely dissatisfied with
ChatGPT’s current risk-control and model-routing
system. I subscribe to the 20× Pro plan, yet I
previously used fewer than 2 pro requests per day on
average, and my Codex usage rarely exceeded 30% of
the available quota. My overall usage has been
modest, with no apparent indication of abuse or
abnormal activity. Despite this, all of my GPT-5.6
Sol Pro requests are now being routed to GPT-5.5
Mini. In practice, this means that the main
high-performance model included in my subscription
is no longer available to me. The system has
provided no clear explanation, no estimated duration
for the restriction, and no meaningful appeal or
review process. I paid for a higher-tier Pro
subscription, but my access has been silently
downgraded despite normal and limited usage. This
opaque and indiscriminate risk-control mechanism
seriously undermines the value of the subscription
and my trust in the advertised Pro benefits. Please
conduct a manual review of my account, explain the
specific reason for this restriction, and restore
access to the models and service level included with
my subscription.
[X Post](https://x.com/zhihe_md/status/2082272498549506488)

"5.6 pro model has been automatically downgraded and
routed to the 5.5 mini model since its release"
(07-23, 9 users)
[OpenAI Developer Community Post](https://community.openai.com/t/5-6-pro-model-has-been-automatically-downgraded-and-routed-to-the-5-5-mini-model-since-its-release/1387941)

"Pro subscription routing to GPT-5.3 Mini for 48+
hours — no reset timer visible" (06-17, 32 users)
[OpenAI Developer Community Post](https://community.openai.com/t/pro-subscription-routing-to-gpt-5-3-mini-for-48-hours-no-reset-timer-visible-case-10179682/1383983)

u/ilsubyeega (06-22): P.S.: The Pro model quietly
redirects to GPT-mini based model. $200/month
[Reddit Post](https://www.reddit.com/r/ChatGPTPro/comments/1v34sg1/ps_the_pro_model_quietly_redirects_to_gptmini/)

u/immortalsol (06-18): I am being silently rerouted
to GPT-5.3 mini when using Pro Extended mode on
ChatGPT webapp. What the hel lis going on? only
started happening today.
[Reddit Post](https://www.reddit.com/r/OpenAI/comments/1u8wyfq/i_am_being_silently_rerouted_to_gpt53_mini_when/)

u/TrainingEngine1 (05-24): My 20x Pro Plan has every
message reverted to 5-Mini and OpenAI refuses to
help. [content deleted]
[Reddit Post](https://www.reddit.com/r/ChatGPTPro/comments/1tm4sq5/my_20x_pro_plan_has_every_message_reverted_to/)

u/Pleasant-Contact-556 (2025-05-02): What are i-cot
and i-mini-m? I got rate-limited on my pro
subscription. It happens occasionally for who knows
what reason, and when it does you can tell because
all of the CoT models route to something.. lesser..
[Reddit Post](https://www.reddit.com/r/OpenAI/comments/1kcrvra/what_are_icot_and_iminim/)
