Small OpenAI reasoning model at high effort: strong math and coding with image input, retiring October 23, 2026.
Output Speed *
Intelligence Index *
Context Window *
Input price
Output price
Performance
Math and Coding Strength Behind a Long Reasoning Delay
Benchmarks
Independent Measurements: Fast Output, Slow First Token
Output Speed
Intelligence Index
MMLU *
GPQA *
HLE *
LiveCodeBench *
Technical Specifications
What the model supports
Comparison
o4-mini (High) or GPT-5 mini: Is the Migration Worth It?
OpenAI's model page describes o4-mini as succeeded by GPT-5 Mini, and both are small, cost-oriented reasoning models. On Artificial Analysis's comparison, both score 17 on the Intelligence Index (estimated for o4-mini), so quality is close on that measure. The difference is speed: 142.2 tokens per second for o4-mini (high) versus 97.9 for GPT-5 mini (high). GPT-5 mini is also scheduled for shutdown on December 11, 2026, so neither is a long-term target.
Choose o4-mini (High) when you are keeping an existing, evaluated pipeline running until the shutdown and want higher measured output speed on long reasoning outputs. Choose GPT-5 mini when you want the model OpenAI names as the successor and a longer runway before retirement. For anything planned beyond 2026, evaluate OpenAI's listed substitute for o4-mini, gpt-5.6-terra, instead of either model.
Limitations & Trade-offs
Best-Fit Workloads
Where this model earns its place
Competition-style math and quantitative reasoning
OpenAI positioned o4-mini as its best-performing benchmarked model on AIME 2024 and 2025 at launch, with 99.5% pass@1 on AIME 2025 when given a Python interpreter. That supports asynchronous solvers, verification pipelines and quantitative analysis where high effort pays off. Tool-assisted scores are not comparable to no-tool scores, and the model's retirement makes it better as a baseline than a new dependency.
Batch debugging and patch generation
OpenAI reports 68.1% on SWE-bench Verified at high reasoning effort on a 477-task subset, and function calling is supported for agent loops. This suits CI-time code repair, review bots and issue triage that can tolerate a delay before the first token. Interactive IDE completion is a poor fit given the measured 30-second first-token latency. Treat vendor SWE-bench scores as scaffold-dependent.
Chart, diagram and screenshot reasoning
OpenAI describes o4-mini as strong in visual tasks, and the API accepts image input alongside text. That fits analysis of charts, technical diagrams or UI screenshots followed by a reasoned text answer, such as financial-report review or bug reproduction from screenshots. Output is text only, and video and audio inputs are not supported.
Migration baselines for retiring pipelines
Teams with prompts already tuned for o4-mini can use o4-mini (High) as a reference when evaluating OpenAI's listed substitute. Replaying identical prompts lets you compare accuracy, latency, structured-output validity and tool-call behavior before the October 23, 2026 shutdown. This is a transitional use, not a recommendation for new production architecture.