GPT-3 and GPT-4 Compared. What Has Actually Changed?

Why Are There So Many New AI Models Lately?

Choosing the right ChatGPT model for your project can feel overwhelming. With each new version, the capabilities change dramatically — and GPT-4 is a massive leap forward from GPT-3.

Let’s break down what really sets them apart, and why GPT-4 is becoming the go-to choice for serious AI applications.

A Quick Look at ChatGPT

ChatGPT is a conversational AI tool built by OpenAI. It is powered by a large language model, or LLM, which allows it to understand prompts and generate meaningful responses — much like a human would.

The underlying technology is called GPT, which stands for Generative Pretrained Transformer. This architecture trains the model using enormous amounts of publicly available text data from across the Internet. The result is a chatbot that can simulate human dialogue with impressive accuracy.

GPT-3 vs GPT-4 — Key Differences Explained

The jump from GPT-3 to GPT-4 is not just incremental. It represents a major upgrade in almost every dimension — from raw power to how well it understands and interacts with information. Here is what sets them apart:

Model Size: From Billions to Trillions

GPT-3 was already powerful with 175 billion parameters. But GPT-4 takes things to another level, reportedly using a mixture-of-experts architecture made up of 8 models, each with 220 billion parameters — adding up to a staggering 1.8 trillion.

More parameters mean better understanding, more nuanced responses, and more room for learning.

Multimodal Abilities: Beyond Just Text

GPT-3 is strictly text-based. It can read and write text, but that’s it.

GPT-4 introduced image understanding — and now, with GPT-4o, OpenAI has moved even further into multimodal territory. GPT-4o can take in and generate text, audio, and images, opening the door to more dynamic and lifelike interactions.

Context Window: Vastly Expanded Memory

GPT-3 can only remember about 2,048 tokens of text — roughly a couple of pages of content.

GPT-4, by contrast, can handle up to 128,000 tokens. That means it can process entire books or long customer conversations without forgetting earlier context. This has huge implications for writing, research, and customer support.

Reasoning and Accuracy: Smarter and More Capable

GPT-4 is not just bigger — it is smarter. According to OpenAI's benchmarks, GPT-3.5 placed in the bottom 10 percent of test-takers on a range of standardized tests. GPT-4 ranks in the top 10 percent.

This makes GPT-4 far better suited for tasks that require complex reasoning, logic, or step-by-step problem solving.

Pricing: Still Free to Use

The best part? Both GPT-3 and GPT-4 are free for everyday use through ChatGPT. OpenAI continues to democratize access to these advanced tools.

What Can You Actually Do with GPT?

The beauty of GPT lies in its flexibility. With a bit of creativity and technical curiosity, you can apply it to nearly any area of your work or life. Companies around the world are already using GPT to automate sales, streamline HR workflows, and even assist with mental health support.

Here are some of the most common and effective ways people are putting GPT to work:

Your Always-On Personal Assistant

From drafting emails to planning your next vacation, GPT can take care of the tasks you would normally outsource to a human assistant. It can suggest dinner ideas, organize your calendar, and generate thoughtful messages — all in seconds and without needing breaks or sleep.

Smarter Customer Support

If your team is spending time answering repetitive questions, GPT-powered chatbots can step in. They are being deployed across websites, apps, and support platforms to resolve customer issues quickly and accurately, offering around-the-clock service without burnout.

Content Creation on Demand

Writers, marketers, and creators are using GPT to brainstorm ideas, draft blog posts, generate social media captions, and even structure long-form content. It acts as a reliable co-pilot that speeds up production while still letting you keep your unique voice.

Making Sense of Data

Need to pull insights from a spreadsheet or summarize a lengthy report? GPT can analyze data, highlight patterns, and deliver actionable insights. It is like having a built-in data analyst who skips the fluff and gets straight to the point.

Help with Code and Development

Whether you are debugging, learning a new language, or automating repetitive tasks, GPT can assist with coding at every level. Developers are using it to review logic, fix bugs, and even generate clean scripts from scratch.

A Brief History of ChatGPT Models

While OpenAI had already introduced large language models with GPT-2 and GPT-3, it was not until GPT-3.5 that the world saw the first version of ChatGPT in action. Since then, the evolution of the models has been rapid — each release bringing more power, speed, and versatility.

GPT-3.5 — The First ChatGPT Model

Launched in November 2022, GPT-3.5 marked the official debut of ChatGPT. It gave users their first taste of conversational AI that felt natural, helpful, and surprisingly humanlike.

GPT-3.5 Turbo — Faster and Sharper

In 2023, OpenAI rolled out GPT-3.5 Turbo, which refined the original version by improving response accuracy and performance, though it still used a similar underlying architecture.

GPT-4 — A Major Upgrade

March 2023 introduced GPT-4, a major step up from previous models. It offered improved reasoning, more accurate answers, and better performance across complex tasks. This version also introduced ChatGPT Plus, a premium plan that gave users access to GPT-4.

GPT-4 Turbo — Bigger Context, More Speed

Later in November 2023, OpenAI released GPT-4 Turbo — an optimized version of GPT-4 with a much larger context window, allowing it to understand and respond to longer conversations or documents without losing track of earlier input.

GPT-4o — The First True Multimodal Model

In May 2024, GPT-4o arrived. The “o” stands for “omni,” reflecting its ability to process and generate not just text, but also images and sound. It represented a turning point in AI, offering truly multimodal interaction that felt more conversational and dynamic.

GPT-4o was also a major win for accessibility — it was twice as fast and half the cost of GPT-4 Turbo and made available to free users with usage limits.

GPT-4o Mini — Affordable and Efficient

By July 2024, OpenAI introduced GPT-4o Mini. It became the new default model in ChatGPT, replacing GPT-3.5 Turbo. Designed to be fast and cost-effective, it made advanced AI even more accessible for developers and businesses through its low-cost API.

Inside the OpenAI o1 Series — What You Should Know

OpenAI’s most recent development, the o1 series, launched on September 12, 2024, and introduced a new phase in the evolution of large language models. Unlike previous models, the o1 family is designed to simulate real reasoning, making it one of the most advanced AI systems released to date.

What Is o1-preview?

The o1-preview model became instantly accessible within ChatGPT after its release, though with limited usage. What sets o1-preview apart is how it processes prompts. Rather than generating a quick reply, the model pauses to reason through each step. It examines the information, considers potential outcomes, and chooses a response only after working through the logic — making its answers slower but more thoughtful and precise.

o1-mini — Streamlined and Cost-Effective

To complement the preview version, OpenAI also launched o1-mini, a smaller, faster, and significantly cheaper model. At 80 percent less cost, it is ideal for day-to-day tasks that still require deep reasoning, such as debugging code, solving math problems, or assisting with technical queries.

Where Is GPT-5?

The o1 release has left many wondering whether it is a preview of GPT-5 or an entirely separate line of models. OpenAI has not confirmed its roadmap yet, so users and developers are left speculating until the next major announcement.

What This Means for Businesses

Models like GPT-4 and o1 are changing how companies operate. With the ability to generate high-quality content at scale, businesses can now automate marketing, customer support, internal documentation, and more.

AI is no longer just a tool for innovation teams — it is becoming a core driver of efficiency, creativity, and growth.

If your organization wants to stay ahead, now is the time to adopt and experiment with these models.

How GPT Can Help You Grow Your Business

The true power of GPT-4 lies in its ability to boost performance across your entire organization. By streamlining repetitive tasks, enhancing communication, and scaling content production, GPT is helping businesses unlock new levels of efficiency and impact.

Whether you are running a startup or scaling a large operation, here are just a few ways GPT can elevate your business:

Scale Content Creation with Ease

Modern language models can generate high-quality content in a fraction of the time it takes a human team. Need daily posts for your social media channels? Want to spin up landing pages or product descriptions? GPT-4 makes it possible to automate your content strategy without sacrificing quality.

The result is a stronger, more consistent digital presence — with less time and fewer resources.

Enhance Customer Support Operations

AI-powered chatbots are now capable of delivering human-like support 24/7. By handling frequently asked questions and common issues, GPT-based solutions can significantly reduce support tickets, improve customer satisfaction, and free up your team to focus on high-value interactions.

Customers get faster answers. Your team gets more time.

Personalize Your Marketing at Scale

With GPT-4, you can generate marketing content that adapts to different audiences. From personalized email campaigns to targeted ad copy, GPT helps you craft messages that speak directly to your customers — increasing engagement and conversion rates across platforms.

Build Custom AI Chatbots for Any Use Case

Thanks to no-code and low-code platforms, building your own AI chatbot is easier than ever.

Botpress offers a flexible platform to create intelligent chatbots for sales, support, onboarding, and more. With drag-and-drop workflows, prebuilt integrations, and powerful AI behind the scenes, it is ideal for teams that want control without complexity.

Want something even simpler? Chatbase lets you upload your data or connect a website, then instantly generate a custom GPT chatbot that understands your content and helps users find what they need.

Ready to Build with GPT?

If you are looking for powerful, easy-to-use tools to start using GPT in your business, we recommend:

• Chatbase – Quickly create your own GPT-powered chatbot by uploading content or connecting a site. Great for lead generation, customer support, and product guidance.

• Botpress – Build fully customized AI assistants using visual tools and smart automation. Ideal for teams with specific workflows or multichannel needs.

Both platforms are free to try and designed to grow with your business.

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About the author

Aitor Alonso is the co-founder of 1 node, where he focuses on building AI-powered systems that automate work and unlock new capabilities for businesses. Passionate about the future of AI, he writes regularly about emerging technologies, especially around AI agents, automation, and how these innovations are shaping the way we work and build.