How to Keep Using GPT-4o After OpenAI Released GPT-5 (Step By Step Guide)

When OpenAI released GPT-4o in 2024, it was widely praised for its creativity, speed, and emotional warmth. For many, it felt like a breakthrough in AI interaction—lively, expressive, and deeply human-like. Then, almost overnight, GPT-4o vanished from the ChatGPT interface, replaced by GPT-5, which—despite major upgrades—has left a significant part of the user base feeling cold, alienated, and frustrated.

This article covers why this shift has upset so many users, what GPT-5 does differently, and most importantly, how to keep using GPT-4o today—even if OpenAI no longer features it in ChatGPT.

Why People Are Upset About GPT-5

Users feel misled
OpenAI had previously implied GPT-4o would stick around. But it disappeared quietly with no announcement. This left many users feeling blindsided and frustrated. Some have canceled their subscriptions or moved to other models like Claude or Gemini.

GPT-4o felt personal
Many users didn’t see GPT-4o as just software. It had a tone that felt warm, creative, and genuinely human. Writers, artists, and people going through tough times often turned to it like a daily companion.

GPT-5 feels colder
While GPT-5 delivers better accuracy, fewer hallucinations, and better results in complex tasks like coding or health advice, a lot of users say it lost the charm. It replies in a more robotic, flat, and repetitive way, which makes it less enjoyable to talk to.

How to Keep Using GPT-4o

Even though GPT-4o is no longer available in the ChatGPT app, it hasn’t been shut down completely. The model still exists and can be used—just not through the main ChatGPT interface. If you preferred GPT-4o’s creative and more natural tone, there are still reliable ways to keep using it. Here’s how:

Option 1: Use a third-party app like Fello AI

If you’re not a developer and just want a simpler way to get GPT-4o back—no coding, no setup—then using a third-party app is your best option. Some apps still offer full access to GPT-4o and let you pick the model directly.

Fello AI is a macOS and iOS app that:

• Supports GPT-4o, GPT-4o Mini, GPT-3.5, Claude, Gemini, and more
• Lets you manually choose the model (including GPT-4o)
• Avoids GPT-5 completely, if that’s what you want
• Keeps the warm, expressive tone many users loved

Steps to Use GPT-4o with Fello AI:

1. Get Fello AI from the Mac App Store (iOS version coming soon).
2. Open the app — no registration or account needed.
3. Click the “Model” button in the top-right corner.
4. Select GPT-4o, GPT-4.1, or the o4-reasoning model from the list.
5. Start chatting — and enjoy the experience you missed.

It also supports switching between different models in a single interface, so you can compare or just stick with what works best.

Other apps worth checking out:

• OpenRouter – a web-based AI interface with multiple models
• Nat.dev – a playground for comparing AI models, including GPT-4o (with limits)
• Custom API integrations – if you know your way around HTTP requests, you can build your own lightweight frontend

Option 2: Access GPT-4o via API

If you’re comfortable with a bit of setup or already familiar with APIs, you can access GPT-4o directly through OpenAI’s developer platform. This option is recommended for tech savvy users who’re not afraid to experiment.

What you need:

• An OpenAI account with billing enabled (a pay-as-you-go setup is fine)
• An OpenAI API key (for authenticating your requests)
• Any client, interface, or app that allows you to manually set the model to gpt-4o

Steps:

1. Log into your OpenAI account and enable billing.
2. Go to platform.openai.com and copy your API key.
3. Use any interface or app that allows you to specify the model—many tools support this.
4. Select gpt-4o as the model name when sending messages.

Why this works:
This method gives you the full GPT-4o experience with no restrictions or substitutes. It’s the cleanest way to keep using it exactly how you want, as long as you’re okay with setting up the interface yourself.

Terminal Example

You can send a request to GPT-4o using a single curl command:

bashCopyEditcurl https://api.openai.com/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-4o",
    "messages": [{"role": "user", "content": "Hello GPT-4o"}]
  }'

Replace YOUR_API_KEY with your actual key. You’ll get a JSON response with GPT-4o’s reply.

Python Example

If you prefer scripting, here’s the same call in Python:

pythonCopyEditimport openai

openai.api_key = "YOUR_API_KEY"

response = openai.ChatCompletion.create(
    model="gpt-4o",
    messages=[{"role": "user", "content": "Hello GPT-4o"}]
)

print(response.choices[0].message.content)

This lets you talk to GPT-4o from any script, app, or terminal.

Claude, Gemini & Other GPT-4o Alternatives

If you’re no longer able to use GPT-4o and don’t want to dive into API setups, there are still great options. Two models in particular stand out for their natural tone and usability: Claude 4 Sonnet y Gemini 2.5 Pro.

Claude 4 is often praised for how human it feels. The Sonnet 4 version is especially good at writing, conversation, and emotional nuance. It’s a solid choice if you used GPT-4o for creative tasks, journaling, or simply liked its warmth and flow.

Gemini 2.5 is fast, responsive, and casual. It’s great for general-purpose use—summaries, research help, or productivity. While not as emotionally rich as Claude, it still feels more natural than GPT-5 and is very easy to work with.

DeepSeek V3 is a lesser-known but capable open-weight model. It’s especially good for reasoning and math-heavy tasks, and often feels more direct than other chatbots. It’s not as “warm” as Claude, but it’s powerful.

Grok 4 is a new contender that excels in reasoning, coding, and staying up-to-date with real-world knowledge (especially when integrated with X/Twitter data). It’s not as emotionally rich, but it’s sharp and assertive—some users prefer that style.

Where to Use Them

You don’t need a developer account or API access. Both models are available through friendly platforms:

• Perplexity – for quick info and research tasks
• Poe – chat-like interface for all major models
• Fello AI – native macOS (soon iOS) app with model switching built in

Whether you miss the personality of GPT-4o or just want a smoother chat experience, Claude and Gemini are strong alternatives worth trying.

GPT-5 Overview

If you’re still curious about GPT-5 — or willing to give it a fair shot — it’s worth noting that this is actually a solid upgrade in many areas. While some users feel let down by the shift in tone and personality, GPT-5 delivers serious improvements under the hood, especially for professional tasks. Here’s where it really shines:

What GPT-5 Does Well

• Smarter response timing
  It automatically decides when to respond quickly and when to “think harder,” depending on the question. You no longer need to switch between fast vs. reasoning modes — it adapts on the fly.
• Health & scientific reasoning
  GPT-5 scored 46.2% on the HealthBench Hard benchmark — its best result yet. It’s now better at handling clinical queries, interpreting research, and supporting complex reasoning in scientific and medical contexts.
• Coding & software tasks
  With a 74.9% score on SWE-bench Verified and 88% on Aider Polyglot, GPT-5 has become a strong assistant for real-world coding. It’s more reliable when fixing bugs, explaining code, or generating small working prototypes on the fly.
• Multimodal input support
  GPT-5 is excellent at combining text and image understanding. It performs well in scenarios where you upload diagrams, charts, or visual data alongside questions.
• Memory & long context
  It supports a 400,000-token context window — that’s over 900 pages of text. If you’re working with long documents, transcripts, or large codebases, GPT-5 can keep track better than any model before it. It also supports persistent memory (if enabled), helping it remember details across chats.
• Fewer hallucinations
  GPT-5 cuts down factual errors significantly — 45% fewer than GPT-4o in regular mode, and up to 80% fewer when using its advanced reasoning mode.

Conclusión

GPT-5 is a strong technical upgrade. It’s more accurate, better at reasoning, and handles complex tasks like coding and health analysis with impressive reliability. For professional use, it’s a solid step forward.

But for many users, GPT-4o offered something GPT-5 doesn’t: personality, emotional warmth, and a more human-like experience. The sudden removal of 4o from ChatGPT, without much warning, left a lot of people feeling frustrated and disconnected.

The good news is GPT-4o isn’t gone completely. You can still use it through the OpenAI API or third-party apps like Fello AI. And if that’s not an option, models like Claude, Gemini, DeepSeek, and Grok offer similar strengths — each with its own personality and use case.

In the end, it depends on what you care about most. If precision and power matter more, GPT-5 is worth a try. But if you’re here for warmth, creativity, and conversation that feels alive, there are still great options — and ways to keep GPT-4o in your toolkit.