Curiosity · AI Model
OpenAI o4-mini
o4-mini is OpenAI's small reasoning model released alongside o3 in April 2025. It applies the same RL-trained reasoning stack used by o3, but at a model size that runs faster and costs several times less — making it the default "thinking tier" for production use while flagship reasoning stays reserved for hardest queries.
Model specs
- Vendor
- OpenAI
- Family
- o-series
- Released
- 2025-04
- Context window
- 200,000 tokens
- Modalities
- text, vision, code
- Input price
- $1.1/M tok
- Output price
- $4.4/M tok
- Pricing as of
- 2026-04-20
Strengths
- Remarkably strong math scores — outperforms o3 on several AIME evals
- Tool use + vision included at a small-model price
- Fast enough for interactive apps, unlike o3 or o1
- Sweet spot for cost-sensitive reasoning pipelines
Limitations
- Smaller knowledge base than flagship models — weaker on obscure facts
- Trails o3 and GPT-5 on the hardest frontier reasoning tasks
- Still consumes reasoning tokens, so outputs can be verbose
- Requires prompt tuning that differs from non-reasoning models
Use cases
- Production reasoning workloads — math tutors, code assistants
- Agent workflows where every call needs a small think step
- Data analysis with Python tool use at scale
- Education apps where cost-per-user matters
Benchmarks
| Benchmark | Score | As of |
|---|---|---|
| AIME 2024 (math) | ≈93% | 2025-04 |
| SWE-bench Verified | ≈68% | 2025-04 |
| GPQA Diamond | ≈82% | 2025-04 |
Frequently asked questions
What is OpenAI o4-mini?
o4-mini is OpenAI's small reasoning model released in April 2025. It uses the same reasoning training pipeline as o3 but at a smaller scale, giving you a thinking-model at roughly 1/10th the cost with very strong math and coding scores.
Is o4-mini better than o3?
On several math benchmarks (notably AIME) o4-mini matches or beats o3. On the hardest frontier tasks, o3 and GPT-5 reasoning still lead. For most production workloads o4-mini is the better cost/quality pick.
How much does o4-mini cost?
As of April 2026, o4-mini is priced around USD 1.10 per million input tokens and USD 4.40 per million output tokens — roughly 10x cheaper than o3 or o1.
Does o4-mini support tools and images?
Yes. Unlike o1, o4-mini supports tool use during chain of thought, including image inputs. This makes it suitable for agentic workloads where the model runs code or analyses screenshots mid-reasoning.
Sources
- OpenAI — Introducing o3 and o4-mini — accessed 2026-04-20
- OpenAI — Pricing — accessed 2026-04-20