GPT-5.1 vs o4-mini Deep Research
GPT-5.1 vs o4-mini Deep Research: GPT-5.1 is cheaper for input-heavy usage ($1.25/M vs $2.00/M input tokens), while GPT-5.1 is better for long-context tasks (1,000,000 tokens).
Direct answer: choose GPT-5.1 for lower token spend and choose GPT-5.1 when your workload needs longer context.
Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.1
o4-mini Deep Research
Cost Differences
o4-mini Deep Research costs less than GPT-5.1
Quick Recommendation
Winner for direct API pricing: o4-mini Deep Research. At the default workload, o4-mini Deep Research saves about $0.75/month ($9.125/year) versus GPT-5.1.
Feature Comparison
| Feature | GPT-5.1 | o4-mini Deep Research |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input Price | $1.25/1M tokens | $2.00/1M tokens |
| Output Price | $10.00/1M tokens | $8.00/1M tokens |
| Context Window | 1,000,000 tokens | 200,000 tokens |
| Max Output | 131,072 tokens | 32,768 tokens |
| Category | flagship | reasoning |
| Capabilities | textvisionaudiocodereasoning | textreasoningcode |
| Release Date | 11/12/2025 | 6/26/2025 |
GPT-5.1 vs o4-mini Deep Research: Which Should You Choose?
Choosing between GPT-5.1 and o4-mini Deep Research depends on your priorities: cost efficiency, context length, or raw capability. o4-mini Deep Research is the more affordable option at $2.00/1M input tokens. Meanwhile, GPT-5.1 offers a significantly larger context window at 1,000,000 tokens vs 200,000 for o4-mini Deep Research.
These models target different tiers: GPT-5.1 is a flagship model while o4-mini Deep Research is reasoning. This means they're optimized for different workloads. GPT-5.1 is built for complex tasks that require deeper reasoning, while o4-mini Deep Research offers better value for routine operations.
Output costs matter too. GPT-5.1 charges $10.00/1M output tokens vs $8.00 for o4-mini Deep Research. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. o4-mini Deep Research has the edge here at $8.00/1M output tokens.
Multimodal capabilities: GPT-5.1 supports vision (image inputs) while o4-mini Deep Research is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose GPT-5.1 when:
- • Budget is a primary concern
- • You need a larger context window (1,000,000 tokens)
- • You need more capabilities (vision, audio)
- • You need longer outputs (up to 131,072 tokens)
- • You're already using OpenAI's API ecosystem
Choose o4-mini Deep Research when:
- • You're already using OpenAI's API ecosystem
Pros and Caveats at a Glance
GPT-5.1
- • Input pricing: $1.25/M tokens
- • Output pricing: $10.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Higher output cost than o4-mini Deep Research
o4-mini Deep Research
- • Input pricing: $2.00/M tokens
- • Output pricing: $8.00/M tokens
- • Context window: 200,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher input cost than GPT-5.1
- • Smaller context window than GPT-5.1
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.1 (OpenAI)
o4-mini Deep Research (OpenAI)
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