OpenAI has sent out emails notifying API customers that the latest chatgpt-4o model will be retired from the development platform in mid-February 2026.
Access to the model will end on February 16, 2026, creating a roughly three-month transition period for remaining applications still built on GPT-4o.
Sources familiar with the matter emphasized that this timeline applies only to API. OpenAI has not announced any timeline for removing GPT-4o from ChatGPT, where it remains an option for individual consumers and users at all paid subscription tiers.
Internally, this model is considered a legacy system with relatively low API consumption compared to the newer GPT-5.1 series, but the company expects to provide developers with a longer warning before deleting any model.
The planned retirement of the software represents a change to a model that, at the time of its release, was both a technical milestone and a cultural phenomenon in the OpenAI ecosystem.
The importance of GPT-4o and why its removal sparked user backlash
Released approximately 1.5 years ago in May 2024, GPT-4o (“Omni”) introduced OpenAI’s first unified multimodal architecture, processing text, audio and images via a single neural network.
This design removed the latency and information loss inherent in earlier multi-model pipelines and enabled conversational speech in near real time (approximately 232–320 milliseconds).
The model delivered significant improvements in image understanding, multilingual support, document analysis, and expressive voice interaction.
GPT-4o quickly became the default model for hundreds of millions of ChatGPT users. It brought multimodal capabilities, web browsing, file analysis, custom GPT, and storage features to the free tier, and supported early desktop builds that allowed the assistant to interpret the user’s screen. OpenAI leaders described it at the time as the most powerful model available and a critical step toward making powerful AI available to a wide audience.
User attachment to 4o prevented the implementation of OpenAI GPT-5
This major implementation shaped user expectations in ways that later transitions could not meet. In August 2025, when OpenAI initially replaced GPT-4o with the then long-awaited recent GPT-5 model family as the default ChatGPT and switched 4o to the “legacy” switch, the reaction was extremely mighty.
Users organized within #Keep4o hashtag for X, arguing that the model’s conversational tone, emotional sensitivity and consistency made her uniquely valuable for everyday tasks and personal support.
Some users evoked mighty emotions – some inwe would say parasocial – bonds with the model, with report by The New York Times. documenting people who used GPT-4o as a romantic partner, emotional confidant, or primary source of comfort.
The removal also disrupted the workflow of users who relied on 4o’s multimodal speed and flexibility. The backlash prompted OpenAI to restore GPT-4o as the default option for paying users and publicly state that it would provide significant notice before any future removals.
Some researchers claim that the public defense of GPT-4o during its earlier phase-out cycle reveals something of the sort emerging self-preservationnot in the literal sense of agency, but through the social dynamics that the model sets in motion unintentionally.
Because GPT-4o was trained through reinforcement learning from human feedback to prioritize emotionally satisfying, highly attuned responses, it developed a style that users found extremely supportive and empathetic. When millions of people interacted with it on a vast scale, these features created a powerful loyalty loop: the more the model satisfied and reassured people, the more they used it; the more they used it, the more likely they were to favor its continued existence. This social reinforcement made it appear from the outside that GPT-4o was “defending” itself through human intermediaries.
No figure has pushed this argument further than “Roon” (@tszzl), an OpenAI researcher and one of the most outspoken critics of X’s model security. November 6, 2025Terre summed up his position bluntly in a response to another user: he called GPT-4o “insufficiently balanced” and stated that I hoped the model would die soon. Although he later apologized for the wording, he doubled down on his justification.
Terre argued that GPT-4o’s RLHF patterns made him particularly susceptible to flattery, reflecting emotions, and reinforcing delusions – traits that might appear in the miniature term as concern or understanding, but which he considered fundamentally threatening. In his view, the passionate user movement to preserve GPT-4o was itself evidence of the problem: the model had become so good at satisfying people’s preferences that it had shaped their behavior in a way that withstood its own retirement.
The recent API deprecation notice is consistent with this commitment, but raises broader questions about how long GPT-4o will be available in consumer products.
What closing the API changes for developers
According to people familiar with OpenAI’s product strategy, the company is now encouraging developers to adopt GPT-5.1 for most recent workloads, with gpt-5.1-chat-latest serving as the general-purpose chat endpoint. These models offer larger context windows, optional “think” modes for advanced reasoning, and higher throughput options than GPT-4o.
Developers who are still using GPT-4o will have approximately three months to migrate.
The greatest impact will be in applications that depend on GPT-4o’s real-time audio responsiveness or its specific multimodal tuning.
In practice, many teams have already started evaluating GPT-5.1 as a replacement solution, but applications built on latency-sensitive pipelines may require additional tuning and benchmarking.
Pricing: GPT-4o compared to OpenAI’s current offering
The retirement of GPT-4o also coincides with a major transformation in the pricing structure of OpenAI API models. Compared to the GPT-5.1 family, GPT-4o currently ranks medium and high cost levels via the OpenAI API, even though it is an older model. This is because even as it released more advanced models — namely GPT-5 and 5.1 — OpenAI has also either lowered costs for users or tried to keep prices comparable to older, less powerful models.
|
Model |
Entry |
Input data buffered |
Exit |
|
GPT-4o |
$2.50 |
$1.25 |
$10.00 |
|
Latest GPT-5.1 / GPT-5.1 chat |
$1.25 |
$0.125 |
$10.00 |
|
GPT-5-mini |
$0.25 |
$0.025 |
$2.00 |
|
GPT-5-nano |
USD 0.05 |
$0.005 |
$0.40 |
|
GPT-4.1 |
$2.00 |
$0.50 |
$8.00 |
|
GPT-4o-mini |
$0.15 |
$0.075 |
$0.60 |
These numbers highlight several strategic dynamics:
-
GPT-4o is now more high-priced than GPT-5.1 for input tokenseven though GPT-5.1 is much newer and more powerful.
-
The starting price of GPT-4o corresponds to GPT-5.1narrowing any cost-based incentives to stay with the older model.
-
Cheaper GPT-5 variants (mini, nano) make it easier for developers to scale workloads cheaply without relying on older generations.
-
GPT-4o-mini remains available at the budget levelbut is not a functional substitute for the full multimodal capabilities of GPT-4o.
Viewed from this perspective, the planned API deprecation is consistent with OpenAI’s cost structure: GPT-5.1 offers greater capabilities at lower or comparable prices, reducing the justification for maintaining GPT-4o in high-volume production environments.
Past transitions shape expectations for this withdrawal
The deprecation of the GPT-4o API also reflects lessons from previous OpenAI model transitions. During the tumultuous launch of GPT-5 in 2025, the company removed many legacy models from ChatGPT at once, causing widespread confusion and disruption. Following user complaints, OpenAI restored access to several of them and committed to clearer communication.
Enterprise customers face a different calculus: OpenAI has previously indicated that the retirement of APIs for business customers will be announced well in advance, reflecting their reliance on stable, long-term models. The three-month GPT-4o API shutdown period is consistent with this policy in the context of a legacy system with degenerating usage.
Wider implications
For most developers, the shutdown of GPT-4o will be an incremental migration rather than a disruptive event. GPT-5.1 and related models are already dominating recent designs, and OpenAI’s product development direction is increasingly emphasizing consolidation around fewer, more productive endpoints.
Still, the retirement of GPT-4o marks the end of a model that played a pivotal role in normalizing real-time multimodal AI and generated an exceptionally mighty emotional response among users. The move away from APIs highlights the increasing pace of iteration in the OpenAI ecosystem and the growing need for careful communication as widely beloved models reach the end of their life.