Published: · Last updated:
We’re excited to announce OpenAI’s newest models on Chat-O. GPT-5 Mini serves as our Balanced default for everyday work, while GPT-5 in the Power tier handles the most demanding tasks. These models joined a rapidly expanding lineup that soon included GPT-OSS-120B and later GLM-5.2 and Kimi K3.
| Capability | GPT-4 | GPT-4.5 | GPT-5 |
|---|---|---|---|
| Step-by-step reasoning | Good | Strong | Excellent |
| Instruction following | Moderate | Good | Strong |
| Code generation | Strong | Strong | Better across stacks |
| Response speed | Slow | Moderate | Fast |
| Multilingual | Good | Good | Strong |
| Consistency | Moderate | Good | High |
Stronger step-by-step reasoning for planning, multi-step instructions, and complex prompts. Better instruction following with higher consistency on tricky edge cases. Improved code generation and refactoring across common stacks. More concise, faster responses without quality loss. More robust multilingual performance.
In practice, you’ll see fewer “gotchas,” stronger tool-use reliability, and better throughput for production work.
Available as our Balanced default, GPT-5 Mini is tuned for speed, cost, and quality:
For users who need even more capable reasoning, we’ve since added models like Kimi K2.6 and GLM-4.7 in the Balanced tier, offering multi-agent and stable reasoning capabilities respectively.
When work is complex or high-stakes, Power tier gives you GPT-5:
The Power tier has since expanded to include GLM-5.1 for long-horizon coding and the Kimi K3 with its 2.8T MoE architecture.
openai/gpt-5-mini openai/gpt-5 Enabled out of the box—no BYOK required. BYOK remains available for other OpenAI models if preferred.
GPT-5 holds its own against the competition. The GLM-5.2 vs Kimi K3 comparison shows how the latest reasoning-focused models stack up against each other. While GPT-5 excels at general-purpose reasoning and tool use, specialized models like GLM-5.2 offer million-token context windows and Kimi K3 pushes parameter counts to new extremes.
For users who want a capable open-weight alternative, GPT-OSS-120B provides comparable reasoning performance under Apache 2.0 licensing.
Early internal testing shows GPT-5 achieving approximately 15-20% higher accuracy on complex multi-step reasoning tasks compared to GPT-4.5, with 30% lower latency. GPT-5 Mini delivers about 90% of GPT-5’s reasoning quality at roughly half the latency and one-third the cost per token—making it one of the best value propositions in our lineup. For cost-sensitive production workloads, GPT-5 Mini often outperforms older GPT-4 models while costing significantly less.
GPT-5 Mini excels in high-throughput scenarios: customer support chatbots, draft generation, content summarization, and rapid prototyping. Its low latency makes it ideal for interactive applications where response time matters. GPT-5, on the other hand, shines in research analysis, complex codebase refactoring, legal document review, and any task requiring deep multi-step reasoning. Users frequently combine GPT-5 for initial analysis and GPT-5 Mini for iterative refinement.
👉 Get started—new users receive 1,000 free credits.
Which model should I choose? Use Balanced (GPT-5 Mini) for everyday tasks and rapid iteration. Choose Power (GPT-5) for complex reasoning, long-form writing, and production-grade work.
Is this BYOK-only? No. Both models are available to all Chat-O users without BYOK. BYOK remains supported for other OpenAI models.
Does this include image generation or web browsing? This announcement covers text chat. Image generation and web search are available through other features and models.
How does GPT-5 compare to GPT-4/4.5? Expect stronger reasoning, better instruction following, and faster, more consistent responses.
How does GPT-5 compare to newer reasoning models? While GPT-5 is a strong generalist, models like Kimi K3 and GLM-5.2 offer specialized capabilities like massive context windows and extreme parameter counts. For most everyday tasks, GPT-5 remains an excellent choice.