Small OpenAI reasoning model with 100K-token outputs, image input and fast generation, now approaching its scheduled October 2026 shutdown.
Output Speed *
Intelligence Index *
Context Window *
Input price
Output price
Performance
Math and Coding Reasoning at Small-Model Speed
Benchmarks
Independent Data: High Output Speed, Long Wait for the 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 Migrating Worth It?
OpenAI's model page names GPT-5 mini as the successor to o4-mini, and both are small, cost-efficient reasoning models. In Artificial Analysis testing at high reasoning settings, the two post the same Intelligence Index score of 17, with the o4-mini figure marked as estimated. o4-mini (High) generated about 142 tokens per second against roughly 98 for GPT-5 mini (high). With the o4-mini API shutdown scheduled for October 23, 2026, the decision is mostly migration timing versus raw output speed.
Choose o4-mini (High) when you maintain an existing integration, value the faster output speed Artificial Analysis measured, and can finish before the shutdown date. Choose GPT-5 mini when starting a new build, when you want the model OpenAI documents as o4-mini's successor, or when you need a path not tied to the October 23, 2026 retirement. Re-test prompts, parameters and token budgets either way, because a replacement is not a guaranteed drop-in.
Limitations & Trade-offs
Best-Fit Workloads
Where this model earns its place
Math and STEM problem solving
OpenAI reported 92.7% on AIME 2025 without tools, 99.5% with a Python interpreter, and 81.4% on GPQA Diamond. This suits quantitative tutoring, solution checking and scientific analysis pipelines. Tool-assisted scores are not comparable to no-tool scores, and your application must supply the interpreter. Expect slow first tokens, so run these jobs asynchronously rather than in a live chat loop.
Bug-fixing and code-review agents
OpenAI reported 68.1% on SWE-bench Verified for o4-mini, close to o3, using a 477-task subset. Function calling and structured outputs support agent loops that return machine-readable patches or review verdicts. OpenAI's run used a 256k context that exceeds the 200,000-token API window and lifted o4-mini's solve rate by about 3%, so expect slightly lower results on very large repositories.
Chart, diagram and screenshot analysis
The model accepts image input alongside text, and OpenAI positioned it for visual tasks. Reported results include 81.6% on MMMU. It fits workflows such as reading charts in reports, interpreting UI screenshots for QA, or extracting reasoning from diagrams. Output is text only, and it cannot process audio or video, so those inputs need separate preprocessing.
High-volume background reasoning
Artificial Analysis measured about 155 tokens per second, well above the median for similar-tier reasoning models, and the 100,000-token output cap allows long reports or multi-step analyses. This suits queued jobs like batch document analysis or report drafting where throughput matters more than first-token delay. The scheduled shutdown limits it to short-horizon or migration-period use.