OpenAI has just unveiled its most powerful reasoning AI models yet – O3 and O4 Mini series. These new models deliver significantly improved performance in mathematics, programming, and visual reasoning while costing less than their predecessors. Understanding what makes each model unique is essential for choosing the right tool for your specific needs.
The New OpenAI Model Landscape Explained
OpenAI’s model ecosystem has become increasingly complex with the April 2025 release. The company has now discontinued the O1 series models (including O1 High and O1 Promote) and replaced them with three new options: O3, O4 Mini, and O4 Mini High.
These models continue OpenAI’s division into two distinct paradigms:
- Standard models: GPT-4o, GPT-4.1, GPT-4.5 – these respond immediately after receiving a prompt
- Reasoning models: The O-series models that trade computation time for superior results
The higher the number following the O, the more advanced the model. For instance, O3 outperforms O1, and O4 Mini surpasses O3 Mini. Within each series, the standard version contains more general knowledge, while the Mini variant offers faster, more cost-effective reasoning for specialized tasks like programming and mathematics.
Benchmark Results Reveal Stunning Performance Gains
The performance improvements from O1 to the new models are remarkable across various benchmarks:
- AIME 2024: Nearly 20 percentage point improvement from O1 to O3/O4 Mini
- Programming competitions: A staggering 700-point ELO increase in Code Force rankings for O4 Mini compared to O3 Mini
- GPA Diamond (doctoral-level scientific questions): Almost saturating this benchmark
- SW Bench Verified: From around 50% accuracy with O1 to nearly 70% with the new models
Perhaps most impressive is the SW Lancer benchmark that measures a model’s ability to complete software engineering tasks worth specific dollar amounts. O3 Mini High previously achieved tasks worth $17,000, while the new models reach $56,000-$65,000 – a 3-4x improvement.
Enhanced Reasoning Through Tool Integration
A major advancement in the O3 and O4 models is full access to all ChatGPT tools during reasoning processes. Unlike previous versions, these models can:
- Search the internet mid-reasoning
- Execute Python code to solve problems
- Access memory systems
- Manipulate images (crop, zoom, focus on regions)
This enables the models to solve complex problems that previous versions couldn’t handle. For example, O4 Mini High can now successfully navigate maze puzzles by generating code to analyze the image, detect edges, and methodically trace a path – tasks that even Google’s Gemini 2.5 Pro struggles with.
Visual Reasoning Capabilities Leap Forward
One of the most exciting improvements is in visual reasoning. The new models can:
- Identify regions of interest in images
- Apply strategic zooming to specific areas
- Use image filtering for better analysis
- Reason about what they’re seeing in real-time
This visual reasoning ability allows O3 and O4 Mini to perform tasks like reading inverted text on objects, identifying badges in cluttered images, and analyzing complex visual scenes with remarkable accuracy.
Chess Analysis and Strategic Problem Solving
The models demonstrate particularly impressive performance when analyzing chess positions – a task that requires spatial reasoning and strategic thinking. In tests with positions that stumped O1 Promote, O3 correctly identified winning moves and provided thorough analysis of possible outcomes.
What’s particularly noteworthy is how the models approach these problems. When analyzing a chess board, O3 attempted to import chess modules via code to enhance its analysis – showing how these new models proactively use every available tool to solve problems.
Comparing Costs and Performance With Competitors
While OpenAI’s new models offer superior performance compared to Google’s Gemini 2.5 Pro, they come at a higher price point. However, the efficiency improvements mean that today’s O3 High delivers results that are 15 percentage points better than what O1 achieved three months ago, at a cost lower than what O1 Low demanded.
This trajectory suggests we’re entering an era where increasingly capable AI becomes available at progressively lower costs – a trend that will likely continue with the upcoming O3 Promote and eventual GPT-5 release expected by summer 2025.
Which Model Should You Choose?
Based on these capabilities, here’s a quick guide to selecting the right model:
- O4 Mini High: Best for programming tasks and when maximum reasoning power is needed
- O3: Ideal for tasks requiring extensive general knowledge combined with powerful reasoning
- O4 Mini: Great for mathematical reasoning and when faster response times are needed
The rapid pace of advancement in AI reasoning capabilities is transforming what’s possible with these systems. Tasks that were impossible just months ago are now handled routinely, making these new models essential tools for anyone working with complex problems requiring computational thinking, visual analysis, or strategic reasoning.