How to Use Older ChatGPT Models: A Step-by-Step Guide

By: Soren

0 Comments

As artificial intelligence becomes more integrated into everyday life, many individuals and organizations are turning to tools like ChatGPT for assistance, creativity, and analysis. However, not everyone wants to use the latest models—some prefer earlier versions due to their response styles, performance characteristics, or compatibility with specific applications. Whether you’re a researcher, developer, or casual user, understanding how to access and use older ChatGPT models can be a beneficial skill.

TLDR: If you want to use older ChatGPT models like GPT-3.5, it’s definitely possible with the right settings and subscriptions. OpenAI maintains availability for previous versions through the ChatGPT interface and API. You’ll need to subscribe to ChatGPT Plus to access GPT-4, which also provides options to toggle back to GPT-3.5. Developers can specify model versions through the OpenAI API using unique model names.

Why Use Older ChatGPT Models?

Older AI models still retain significant value and utility. Here are some reasons why users may prefer them:

Faster Response Times: Previous iterations often process inputs more quickly, making them ideal for tasks requiring speed over depth.
Cost Efficiency: Using older models is typically cheaper, especially when accessed through the OpenAI API.
Simpler Output: Some users find earlier models like GPT-3.5 to be less verbose and more direct, aligning better with particular workflows.
Compatibility: Certain applications and scripts may have been originally optimized to work with earlier versions and feature sets.

Step-by-Step Guide to Using Older ChatGPT Models

1. Understand the Model Names

To use a specific model, you first need to know its identifier. As of 2024, older ChatGPT models include:

GPT-3.5 – Referred to as gpt-3.5-turbo
GPT-4 (still available but not the latest variant) – Referred to as gpt-4
GPT-4-turbo – Variant of GPT-4 with optimizations (October 2023 release)

Knowing the correct model identifier is essential whether you’re using the ChatGPT interface or the OpenAI API.

2. Subscribe to ChatGPT Plus (If Using ChatGPT Interface)

To access and switch between different GPT models in the ChatGPT web interface, you’ll need to have a ChatGPT Plus subscription, which currently costs $20/month. Here’s what you should do:

Go to chat.openai.com.
Sign in with your OpenAI credentials.
Click on “Upgrade to Plus” on the left-hand sidebar and follow the subscription process.

Once you’re subscribed, both GPT-3.5 and GPT-4 (including the Turbo variant) will be available. No additional configuration is needed—just select the model you want in the top-center model selector.

3. Switching Models Within ChatGPT

After upgrading your account, follow these steps to use the model of your choice:

Start a new chat session.
Click on the model name dropdown at the top (It may show GPT-4 by default).
Select GPT-3.5 from the list if you want to use the older model.

Once selected, all your prompts in that chat session will use that version until you switch again or start a new session.

4. Accessing Older Models via the OpenAI API

For developers preferring programmatic access, OpenAI’s API provides flexibility in choosing model versions. Here’s how to set it up:

Create an OpenAI account at platform.openai.com.
Get your API key by navigating to the API dashboard and copying your personal API token.
Use the right endpoints and model names in your application. Example in Python using openai library:

import openai

openai.api_key = "your-api-key"

response = openai.ChatCompletion.create(
    model="gpt-3.5-turbo",
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "Tell me a joke."}
    ]
)

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

This call will route through the GPT-3.5 model instead of the latest default.

5. Comparing Model Behavior

Understanding the difference in responses between model variations can be vital. Older models may:

Provide less refined natural language responses.
Be more prone to hallucinations or factual inaccuracies.
Show simpler sentence structures and reasoning pathways.

Therefore, if you are conducting user studies or developing AI evaluation methods, using an older model consistently provides a stable baseline.

6. Limiting Memory and Access Features

As of 2024, newer models support memory, tool use (such as DALL·E, Code Interpreter, and web browsing), and file uploads, while older models do not. When using GPT-3.5 on the ChatGPT platform:

No memory: It won’t recall previous session interactions.
Limited tools: Cannot use mapping, visual creation, or third-party plugins.

This makes GPT-3.5 a good choice for “air-gapped” or data-sensitive interactions, where historical recall could create potential risks or data leaks.

Best Practices When Using Older Models

Define Prompts Precisely: Older models benefit from exact, intentional prompts to mitigate limitations in contextual reasoning.
Limit Session Length: Because memory and context retention over long thread lengths may degrade quicker, keep conversations focused.
Test Ahead of Deployment: If using via API, test thoroughly to see if GPT-3.5 meets your functionality and cost expectations.

FAQs

Q: Can I still use GPT-3 or earlier models like text-davinci-002?

A: OpenAI has deprecated many of the original GPT-3 completions models. However, “turbo” versions based on similar architectures, like gpt-3.5-turbo, are still supported. For most applications, GPT-3.5 is the recommended fallback for a legacy-like experience.

Q: Does GPT-3.5 behave differently from GPT-4-turbo?

A: Yes. GPT-4-turbo generally exhibits more advanced reasoning and creative capabilities. GPT-3.5 is lighter, faster, and often more deterministic in its results—preferred by developers for certain constrained tasks.

Q: Is using an older model secure?

A: Security depends more on your implementation than the model version. That said, GPT-3.5 does not save memory or recall interactions, which adds one level of data privacy. Always verify output and apply standard API security protocols.

Conclusion

While it’s tempting to chase the latest in AI, using older ChatGPT models remains both valid and practical. Whether for faster execution, reduced costs, or testing consistency, GPT-3.5 and similar models still offer great value. Accessing them via ChatGPT Plus or the OpenAI API is straightforward as long as you follow the correct steps.

By understanding the strengths and restrictions of older models, users can make smarter decisions for development, education, and integration of AI in real-world tasks.