OpenAI o4-mini Pricing 2026: $1.10/$4.40 Budget Reasoning Model
The cheapest way to get OpenAI chain-of-thought reasoning — but shutting down October 23, 2026. Here's what you need to know and how to migrate.
⚠️ Deprecation Notice: o4-mini shuts down Oct 23, 2026
OpenAI is deprecating o4-mini on October 23, 2026. It will be replaced by GPT-5.6 Terra ($2.00/$12.00) for general tasks and GPT-5.6 Sol for complex reasoning. If you rely on o4-mini for budget reasoning, start planning your migration now — see the migration guide below.
OpenAI's o4-mini is the company's budget reasoning model — a smaller, cheaper version of the o4 family that still uses chain-of-thought thinking to solve complex problems. At $1.10 input and $4.40 output per 1M tokens, it's the cheapest way to access OpenAI's reasoning capabilities.
Reasoning models differ from standard LLMs: they "think" step by step before answering, which makes them significantly better at math, logic, coding, and multi-step analysis. o4-mini brings that capability down to a budget price point — though with a deprecation deadline attached.
o4-mini vs o3-mini: Same Price, Newer Model
| Model | Input / 1M | Output / 1M | Context | Reasoning | Status |
|---|---|---|---|---|---|
| o4-mini | $1.10 | $4.40 | 200K | Chain-of-thought | Deprecating Oct 23 |
| o3-mini | $1.10 | $4.40 | 200K | Chain-of-thought | Deprecating Oct 23 |
o4-mini and o3-mini are identically priced at $1.10/$4.40 with 200K context. o4-mini is the newer model with improved reasoning accuracy on math, coding, and science benchmarks. Both are being deprecated on the same timeline. If you're still on o3-mini, switch to o4-mini for better quality at no extra cost — then migrate to GPT-5.6 Terra before October 23.
How o4-mini Compares to Budget Competitors
| Model | Input / 1M | Output / 1M | Context | Provider | Reasoning? |
|---|---|---|---|---|---|
| o4-mini | $1.10 | $4.40 | 200K | OpenAI | Yes (CoT) |
| GPT-5.4 nano | $0.20 | $1.25 | 128K | OpenAI | No |
| Gemini 2.5 Flash | $0.30 | $2.50 | 1M | Optional | |
| Claude Haiku 4.5 | $1.00 | $5.00 | 200K | Anthropic | No |
| DeepSeek V4 Flash | $0.22 | $0.66 | 128K | DeepSeek | No |
| Mistral Small 4 | $0.15 | $0.60 | 128K | Mistral | No |
| Kimi K2.6 | $0.95 | $4.00 | 256K | Moonshot | No |
o4-mini is more expensive than non-reasoning budget models — DeepSeek V4 Flash is 5x cheaper on output, Mistral Small 4 is 7x cheaper. The premium buys you chain-of-thought reasoning, which dramatically improves accuracy on complex tasks. If your workload doesn't need reasoning, you're overpaying. If it does, o4-mini is the cheapest reasoning option from OpenAI.
Use Cases for Budget Reasoning Models
Where o4-mini shines:
- Math and quantitative analysis — Step-by-step problem solving for financial calculations, statistics, and scientific computing
- Code generation and debugging — Multi-step coding tasks where the model needs to reason through logic before writing code
- Data extraction and transformation — Complex parsing tasks that require understanding structure, not just pattern matching
- Multi-step API orchestration — Agentic workflows where the model plans actions across multiple tools
- Logic puzzles and constraint satisfaction — Problems with multiple constraints that benefit from explicit reasoning chains
- Document analysis with inference — Reading contracts, reports, or research papers where conclusions require multi-hop reasoning
The key insight: reasoning models are overkill for simple tasks. If you're doing basic classification, summarization, or translation, use a non-reasoning model like GPT-5.4 nano ($0.20/$1.25) instead. Reserve o4-mini for tasks where step-by-step thinking genuinely improves output quality.
Real-World Cost: 25K Reasoning Tasks/Month
| Model | Monthly Cost | Notes |
|---|---|---|
| o4-mini | $385 | 2K input, 3K output per task (reasoning tokens included in output) |
| o3-mini | $385 | Same price, older model |
| GPT-5.6 Terra (replacement) | $1,000 | $2.00/$12.00 — 2.6x more expensive |
| Claude Haiku 4.5 | $438 | No reasoning, but close in price |
| Gemini 2.5 Flash | $203 | Optional reasoning, cheaper |
| GPT-5.4 nano | $106 | No reasoning — 73% cheaper |
The migration cost shock: When o4-mini shuts down and you move to GPT-5.6 Terra, your reasoning workload costs jump from $385/month to $1,000/month — a 2.6x increase. If Gemini 2.5 Flash's optional reasoning meets your quality needs, it's the most cost-effective alternative at $203/month.
Migration Guide: o4-mini to GPT-5.6
Migration timeline: October 23, 2026
- For general reasoning tasks: Migrate to GPT-5.6 Terra ($2.00/$12.00 per 1M tokens). This is the direct replacement for o4-mini's use cases, though at a higher price point.
- For complex multi-step reasoning: Use GPT-5.6 Sol — designed for the hardest reasoning tasks where accuracy matters more than cost.
- For cost-sensitive workloads: Evaluate Gemini 2.5 Flash ($0.30/$2.50) with optional reasoning enabled, or GPT-5.4 nano ($0.20/$1.25) if you can accept non-reasoning quality.
- For hybrid approaches: Route simple tasks to GPT-5.4 nano and reserve GPT-5.6 Terra only for tasks that truly need reasoning. This can cut costs by 60-70%.
Action items before October 23:
- Audit your o4-mini usage — identify which requests actually benefit from reasoning vs. which could use a cheaper non-reasoning model
- Test GPT-5.6 Terra on your reasoning workloads — quality may differ from o4-mini, so validate before migrating
- Implement model routing if possible — send simple tasks to nano, complex tasks to Terra
- Budget for the cost increase — GPT-5.6 Terra is 2.6x more expensive than o4-mini
The Verdict
o4-mini is an excellent budget reasoning model — the cheapest way to get OpenAI's chain-of-thought capabilities. At $1.10/$4.40, it undercuts Claude Haiku 4.5 on output cost while including reasoning that Haiku lacks.
But the clock is ticking. With an October 23, 2026 shutdown date, you have weeks — not months — to plan your migration. The replacement (GPT-5.6 Terra at $2.00/$12.00) is 2.6x more expensive, so this deprecation will hit your budget hard if you rely on o4-mini at scale.
If you're starting a new project today, don't build on o4-mini. Go straight to GPT-5.6 Terra or evaluate whether Gemini 2.5 Flash's optional reasoning can meet your needs at a fraction of the cost.
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