Curiosity · AI Model
GPT-5 mini
GPT-5 mini is the mid-tier of OpenAI's GPT-5 family, released alongside the flagship in August 2025. It inherits GPT-5's unified router (automatic think-vs-chat switching) and tool-use stability, but runs at a fraction of the cost — making it the default pick for production chat, agents, and RAG pipelines where full GPT-5 is overkill.
Model specs
- Vendor
- OpenAI
- Family
- GPT-5
- Released
- 2025-08
- Context window
- 400,000 tokens
- Modalities
- text, vision, code
- Input price
- $0.25/M tok
- Output price
- $2/M tok
- Pricing as of
- 2026-04-20
Strengths
- Unified model handles easy chat and harder reasoning without model switching
- Excellent cost-per-quality — roughly 5x cheaper than flagship GPT-5
- Strong tool-use reliability inherited from GPT-5 training
- Large 400K context suffices for most real-world documents
Limitations
- Trails flagship GPT-5 on frontier reasoning, research-grade code
- Vision quality below top-tier for dense document OCR
- Effort-routing can occasionally over-think simple prompts, adding latency
Use cases
- High-volume chatbots and support agents
- RAG pipelines where cost per query is the constraint
- Content generation and summarisation at scale
- Tool-calling agents where full GPT-5 is cost-prohibitive
Benchmarks
| Benchmark | Score | As of |
|---|---|---|
| SWE-bench Verified | ≈65% | 2025-10 |
| AIME 2024 (math) | ≈85% | 2025-10 |
| MMLU-Pro | ≈80% | 2025-10 |
Frequently asked questions
What is GPT-5 mini?
GPT-5 mini is the mid-tier of OpenAI's GPT-5 model family, released in August 2025. It uses the same unified reasoning-and-chat architecture as flagship GPT-5 but at roughly one-fifth the price, making it the default choice for production deployments.
When should I use GPT-5 mini versus GPT-5?
Use GPT-5 mini for high-volume production workloads — chat, RAG, standard agents — where cost matters. Use flagship GPT-5 for frontier reasoning, complex coding agents, and cases where quality outranks cost.
How much does GPT-5 mini cost?
As of April 2026, GPT-5 mini is priced around USD 0.25 per million input tokens and USD 2 per million output tokens — roughly five times cheaper than flagship GPT-5.
Does GPT-5 mini support reasoning?
Yes. GPT-5 mini uses the same unified reasoning architecture as flagship GPT-5, automatically deciding when to engage extended thinking based on prompt difficulty. You can also force reasoning effort via API parameters.
Sources
- OpenAI — Introducing GPT-5 — accessed 2026-04-20
- OpenAI — Pricing — accessed 2026-04-20