GPT-3.5 Model: A Complete Guide on What It Is and Its History

GPT-3.5 is an improved version of GPT-3, offering better performance and understanding of human language. ChatGPT members use the GPT-3.5 model as their default model

Here, we will take a closer look at what OpenAI’s GPT-3.5 is and explain the differences between it, GPT-3, and the latest model, GPT-4.

OpenAI’s GPT-3.5 Model

The GPT-3.5 model is not a single model but a collection of different models optimized for various domains. There are a total of 7 different GPT-3.5 models available. These models serve different purposes and have varying token limits and training data.

OpenAI recommends using the gpt-3.5-turbo model among the other GPT-3.5 models due to its advantages of lower cost and improved performance. For reference, visit the related page.

Below, you can find details about each model:

ModelDescriptionMaximum TokensTraining Data
gpt-3.5-turboOptimized for chat applications, offering similar performance to text-davinci-003 at 1/10th the cost.4,096Up to Sep 2021
gpt-3.5-turbo-16kSame capabilities as gpt-3.5-turbo but with four times the context, allowing for longer conversations and larger input.16,384Up to Sep 2021
gpt-3.5-turbo-0613A snapshot from June 13, 2023, with function calling data. No updates; deprecated after three months from a new version.4,096Up to Sep 2021
gpt-3.5-turbo-16k-0613A snapshot from June 13, 2023. No updates; deprecated after three months from a new version.16,384Up to Sep 2021
text-davinci-003 (Legacy)Capable of language tasks with better quality, longer output, and more consistent instruction-following. Supports inserting text.4,097Up to Jun 2021
text-davinci-002 (Legacy)Similar capabilities to text-davinci-003 but trained using supervised fine-tuning instead of reinforcement learning.4,097Up to Jun 2021
code-davinci-002 (Legacy)Optimized for code-completion tasks, useful for programming-related queries.8,001Up to Jun 2021
All GPT-3.5 models and their explanation

The History of GPT-3.5 Model

OpenAI had announced the GPT-3 model on June 11, 2020. They introduced new versions of its AI models, GPT-3 and Codex, to their API on March 15, 2022 via a blog post. These models named “text-davinci-002” and “code-davinci-002” had enhanced capabilities for text editing and insertion of the current model.

On November 28, 2022, OpenAI released another AI model called “text-davinci-003.” Shortly after, on November 30, 2022, OpenAI began categorizing these models as part of the “GPT-3.5” series.

November 30, 2022, is also the date when ChatGPT was announced.

Therefore we can say that the GPT-3.5 model was first released on March 15, 2022. Its predecessor is the GPT-3 language model, and the subsequent model is the GPT-4 model. However, the it has been receiving updates since its initial release date.

To learn more, take a look at our post where we examine all GPT models of OpenAI.

Number of Parameters used to train GPT-3.5

The GPT-3.5 model was trained using 175 billion parameters, which were obtained from various sources. The distribution of these sources for training the model is as follows:

Web Crawling60%

These sources were utilized to gather a diverse range of data for training the model.

Character Limit in GPT-3.5 model

The GPT-3.5 model has a character limit. It can’t understand and provide unlimited responses.

Each model within GPT-3.5 has a different character limit, which is determined based on tokens. Tokens are a type of character, and roughly 100 tokens are equivalent to 75 English characters. You can find approximate character limits for each model below.

ModelCharacter Limit
text-davinci-003 (Legacy)3,073
text-davinci-002 (Legacy)3,073
code-davinci-002 (Legacy)6,001

How to access and use GPT-3.5 model?

To access the GPT-3.5 model, there are three primary methods available:

  1. ChatGPT: Through ChatGPT, you can access to the GPT-3.5 model. The default model of ChatGPT is GPT-3.5. Plus members have access to both the GPT-3.5 and GPT-4 models.
  2. OpenAI Playground: You can access the GPT-3.5 model through the OpenAI Playground. It provides a user-friendly interface and allows you to interact with the model and customize various parameters without requiring extensive programming knowledge.
  3. API Integration: The third method is to call the GPT-3.5 model’s API. You can implement this in any programming language of your choice. However, there is a cost associated with each API call based on the number of tokens used.

Also Read: How to call GPT API?

Below is a simplified example of how to call the GPT-3.5 model in Python:

import openai

openai.api_key = 'your-api-key'

def call_gpt3(prompt, tokens=100):
    response = openai.Completion.create(
    return response.choices[0].text.strip()

response = call_gpt3("Translate the following English text to French: '{Hello, how are you?}'", tokens=60)

Remember to replace 'your-api-key' with your actual API key.

Price of Using GPT-3.5 API

The usage fee for the GPT-3.5 model is charged per token used.

Below are the usage fees for the Turbo model:

ContextInput RateOutput Rate
4K$0.0015/1,000 tokens$0.002/1,000 tokens
16K$0.003/1,000 tokens$0.004/1,000 tokens

These prices are approximately 20 times lower compared to the usage of the GPT-4 API. For more information, take a look at OpenAI API pricing page.

GPT-3.5 vs GPT-3: What is the difference?

GPT-3.5 and GPT-3 are both models of artificial intelligence developed by OpenAI, designed for advanced natural language processing tasks. However, there are key differences between the two that position GPT-3.5 as a more evolved version of GPT-3.

ChatGPT is designed for advanced human interactions and is used as the default model over GPT-3.5 due to its cost-effectiveness and superior performance.

Learn More: All You Need to Know About ChatGPT

GPT-3.5 vs GPT-4: A Comparison

OpenAI announced its latest language model, GPT-4, on March 14, 2023.

They have not disclosed the exact number of parameters they used to train GPT-4. However, estimates suggest that it’s about ten times greater than that of GPT-3.5, indicating a substantial leap in complexity and processing power.

Learn more about GPT-3.5 vs GPT-4 comparison.

A key distinguishing feature between GPT-4 and its predecessor is its multimodal capability. GPT-4 has the ability to accept both text and image inputs, making it a significantly more versatile model. In contrast, GPT-3.5 only supports text inputs.

Learn More: GPT-4 Image Input How to Use it?

The character limit for the most advanced version of GPT-4 is approximately 25,000, double that of GPT-3.5, which sits around 12,000. This allows GPT-4 to handle much larger chunks of information at once, potentially improving comprehension and response quality.

In terms of cognitive performance, GPT-4 is designed with enhanced reasoning abilities and creativity, enabling it to perform better in complex problem-solving scenarios. In tests, GPT-4 outperformed GPT-3.5, scoring higher in approximate percentiles among test-takers. Learn the performance comparisons in the exam scores between GPT-3.5 and GPT-4.

However, these enhancements come with increased costs and slower response times. The usage fee for the GPT-4 API is about 20 times higher than GPT-3.5.

Additionally, GPT-4 responds about 1.7 times slower than GPT-3.5, likely due to the increased computational load from the larger parameter count and multimodal capabilities.