GPT-5.1 vs GPT-5.4 Pro
GPT-5.1 vs GPT-5.4 Pro: GPT-5.1 is cheaper for input-heavy usage ($1.25/M vs $30.00/M input tokens), while GPT-5.4 Pro is better for long-context tasks (1,050,000 tokens).
Direct answer: choose GPT-5.1 for lower token spend and choose GPT-5.4 Pro 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
GPT-5.4 Pro
Cost Differences
GPT-5.4 Pro costs more than GPT-5.1
Quick Recommendation
Winner for direct API pricing: GPT-5.1. At the default workload, GPT-5.1 saves about $341.25/month ($4,151.875/year) versus GPT-5.4 Pro.
Feature Comparison
| Feature | GPT-5.1 | GPT-5.4 Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input Price | $1.25/1M tokens | $30.00/1M tokens |
| Output Price | $10.00/1M tokens | $180.00/1M tokens |
| Context Window | 1,000,000 tokens | 1,050,000 tokens |
| Max Output | 131,072 tokens | 131,072 tokens |
| Category | flagship | reasoning |
| Capabilities | textvisionaudiocodereasoning | textvisioncodereasoning |
| Release Date | 11/12/2025 | 3/6/2026 |
GPT-5.1 vs GPT-5.4 Pro: Which Should You Choose?
Choosing between GPT-5.1 and GPT-5.4 Pro depends on your priorities: cost efficiency, context length, or raw capability. GPT-5.1 is the more affordable option at $1.25/1M input tokens — 96% cheaper than GPT-5.4 Pro. Meanwhile, GPT-5.4 Pro offers a significantly larger context window at 1,050,000 tokens vs 1,000,000 for GPT-5.1.
These models target different tiers: GPT-5.1 is a flagship model while GPT-5.4 Pro is reasoning. This means they're optimized for different workloads. GPT-5.1 is built for complex tasks that require deeper reasoning, while GPT-5.4 Pro offers better value for routine operations.
Output costs matter too. GPT-5.1 charges $10.00/1M output tokens vs $180.00 for GPT-5.4 Pro. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. GPT-5.1 has the edge here at $10.00/1M output tokens.
Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.
Best Use Cases
Choose GPT-5.1 when:
- • Budget is a primary concern
- • You need more capabilities (audio)
- • You're already using OpenAI's API ecosystem
Choose GPT-5.4 Pro when:
- • You need a larger context window (1,050,000 tokens)
- • 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
- • Smaller context window than GPT-5.4 Pro
GPT-5.4 Pro
- • Input pricing: $30.00/M tokens
- • Output pricing: $180.00/M tokens
- • Context window: 1,050,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Higher input cost than GPT-5.1
- • Higher output cost than GPT-5.1
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.1 (OpenAI)
GPT-5.4 Pro (OpenAI)
Start using GPT-5.1 today
Sign Up for OpenAI →Start using GPT-5.4 Pro today
Sign Up for OpenAI →Frequently Asked Questions
Which is cheaper, GPT-5.1 or GPT-5.4 Pro?▼
What is the context window difference between GPT-5.1 and GPT-5.4 Pro?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Related Comparisons
Related Articles
Learn when to pick each model, then compare live pricing scenarios.