We find ourselves in the midst of the third year of the AI boom, and industry leaders continue to push boundaries without showing any signs of slowing down. ChatGPT stands as the undisputed leader, but with over half a dozen models available from OpenAI alone, choosing the right one for a specific project can be a challenging task.

Recommended Models for Your Projects

o1 - The Unrivaled Reasoning Model

OpenAI CEO Sam Altman spent a significant part of 2024 teasing the release of Project Strawberry. Finally, in September, the company unveiled it as OpenAI's first "reasoning" model, renaming it "o1". Just like the two-stage release of GPT-2, a stripped-down version was released first, and GPT Plus subscribers got access to the o1-preview version. As a reasoning model, o1 is known for using humanlike reasoning to check its answers before providing more accurate responses to complex science, math, and coding queries. Trained with a new optimization algorithm and a tailored training dataset, o1 outperforms the GPT-4o family of models in industry benchmark tests. The full version of OpenAI o1 made its debut in December 2024 during the company's 12 Days of OpenAI livestream event. Its internal system of checks helps it hallucinate less than its predecessors. According to OpenAI's tests, the new version reduces "major errors" on "difficult real-world questions" by 34% compared to the preview version. However, it is currently only available to Plus or Teams subscribers, with a limit of 50 messages per week at that level. A Pro subscription costing $200 per month is required for unlimited use.

o1-mini - The Lightweight Problem Solver

OpenAI's o1-mini is a lightweight version of the company's larger reasoning model. It is designed to quickly solve challenging mathematics and coding problems rather than generating creative prose. Built for speed, it provides fast and efficient solutions for specific technical tasks, making it ideal for task automation. Unlike the preview model, o1-mini can be accessed with a Plus subscription, offering 50 messages a day. Pro subscribers, who pay $200 a month, have unlimited access to the mini model.

GPT-4o - The Omni-Performing Model

Introduced in May 2024, GPT-4o (the "o" stands for "omni") is OpenAI's "latest, fastest, highest intelligence model". It offers human-level response times, crucial for features like Advanced Voice Mode, and improved performance with languages beyond English. It also has a better understanding of vision and audio content. This model is faster, more efficient, and more cost-effective than its predecessors and has achieved state-of-the-art results in multilingual and vision benchmark tests. It can generate text, images, audio, and computer code. After a pre-Thanksgiving update, it received a minor boost to its creative writing skills. It is accessible through the free tier of ChatGPT but comes with restrictive usage caps. Subscribing to the $20-per-month Plus tier significantly increases the usage cap.

GPT-4o mini - The Quick Task Completion Model

OpenAI's "lightest-weight intelligence model" is GPT-4o mini. It is designed for quickly completing computationally simple tasks repeatedly rather than handling complex coding or analytical problems. It offers nearly all the features of the larger 4o model except for access to some advanced analytical tools. GPT-4o mini is available to Plus and Pro subscribers and can be selected from the drop-down model list in the upper left corner of the ChatGPT home screen. It can also be accessed by free-tier users by using up their GPT-40 usage allowance. Once the user is out of the cool-down period, they can access GPT-4o again.

GPT-4 - The Capable Base Model

Launched in April 2023 alongside the new ChatGPT Plus subscription tier, GPT-4 powered both ChatGPT and Microsoft's free Copilot platform. OpenAI touted GPT-4 as "more reliable, creative, and able to handle much more nuanced instructions than GPT-3.5". It was also the company's first multimodal model, capable of generating and analyzing images and audio in addition to text. GPT-4 still serves as the base model for free-tier ChatGPT users. For most casual users, GPT-4 and its "omni" variants are sufficient for performing inference tasks.

Early Versions - The Pioneers

GPT-1, the original large language model from OpenAI, made its debut in June 2018 and became the archetype of generative pre-trained transformer technology. Even in its earliest form, it outperformed the state-of-the-art models of the time by nearly 6% at natural language inference tasks. Its 1.5-billion-parameter successor, GPT-2, arrived in November 2019 and expanded on GPT-1's capabilities to include answering questions, summarizing documents, and translating text. GPT-3 came in May 2020 but was quickly licensed by Microsoft in September. The GPT-3.5 model is a subset of Microsoft's licensed GPT-3 with better performance and a later knowledge cutoff date. When OpenAI launched the ChatGPT platform in November 2022, it ran on the GPT-3.5 model. The company incorporated web browsing capabilities in April 2023, but by May 2023, GPT-3.5 had been replaced by the more capable GPT-4 family of models and is no longer available for public use, only accessible through OpenAI's developer API.