Last verified 2025-11-26 (left) · 2025-11-26 (right)
Claude Opus 4.5 vs GPT-5.1 — Pricing & Capability Comparison
Claude Opus 4.5 charges $5.00 per million input tokens and $25.00 per million output tokens. GPT-5.1 comes in at $1.25 / $10.00. Context windows span 200K vs 200K tokens respectively.
TL;DR — Quick Comparison
- ✓GPT-5.1 is cheaper overall: $11.25 per 1M tokens (in+out) vs $30.00 for Claude Opus 4.5 — saves $18.75 per 1M tokens
- ✓Input pricing: Claude Opus 4.5 $5.00/1M vs GPT-5.1 $1.25/1M
- ✓Output pricing: Claude Opus 4.5 $25.00/1M vs GPT-5.1 $10.00/1M
- ✓Context window: Claude Opus 4.5 offers more (200K vs 200K)
- ✓Use our calculator below to estimate costs for your specific usage pattern
Input price (per 1M)
Claude Opus 4.5
$5.00
GPT-5.1
$1.25
GPT-5.1 leads here
Output price (per 1M)
Claude Opus 4.5
$25.00
GPT-5.1
$10.00
GPT-5.1 leads here
Context window
Claude Opus 4.5
200,000 tokens
GPT-5.1
200,000 tokens
Claude Opus 4.5 leads here
Cached input
Claude Opus 4.5
$0.500
GPT-5.1
$0.125
GPT-5.1 leads here
Cost comparison for 10K-token workloads
Side-by-side pricing for identical workloads (10,000 total tokens per request) across different distributions.
| Scenario | Claude Opus 4.5 | GPT-5.1 | Claude Opus 4.5 cached | GPT-5.1 cached |
|---|---|---|---|---|
Balanced conversation 50% input · 50% output | $0.150 | $0.0563 | $0.128 | $0.0506 |
Input-heavy workflow 80% input · 20% output | $0.0900 | $0.0300 | $0.0540 | $0.0210 |
Generation heavy 30% input · 70% output | $0.190 | $0.0738 | $0.177 | $0.0704 |
Cached system prompt 90% cached input · 10% fresh output | $0.0700 | $0.0212 | $0.0295 | $0.0111 |
Frequently asked questions
Which is cheaper: Claude Opus 4.5 or GPT-5.1?
GPT-5.1 is cheaper for input tokens at $1.25 per 1M tokens compared to $5.00. For output, GPT-5.1 costs $10.00 per 1M tokens versus $25.00 for Claude Opus 4.5.
What is the cost per 1M tokens for Claude Opus 4.5?
Claude Opus 4.5 pricing: $5.00 per 1M input tokens and $25.00 per 1M output tokens. Context window: 200,000 tokens.
What is the cost per 1M tokens for GPT-5.1?
GPT-5.1 pricing: $1.25 per 1M input tokens and $10.00 per 1M output tokens. Context window: 200,000 tokens.
How much does it cost per 1K tokens?
Per 1K tokens: Claude Opus 4.5 costs $0.0050 input / $0.0250 output. GPT-5.1 costs $0.0013 input / $0.0100 output. This is useful for calculating small-scale usage costs.
Which model supports a larger context window?
Claude Opus 4.5 offers 200,000 tokens (200K) versus 200K for GPT-5.1.
What is the estimated monthly cost for typical usage?
For a typical workload of 10M input + 2M output tokens per month: Claude Opus 4.5 would cost approximately $100.00, while GPT-5.1 would cost $32.50. GPT-5.1 is more economical for this usage pattern.
Do these models support prompt caching?
Claude Opus 4.5 supports prompt caching at $0.500 per 1M cached tokens, reducing costs for repeated context by up to 90%. GPT-5.1 supports caching at $0.125 per 1M tokens, saving up to 90%.
Which model is best for my use case?
Choose GPT-5.1 for cost-sensitive applications with high input volume. Choose Claude Opus 4.5 if you need 200K context for long documents or conversations. Consider prompt caching if you have repeated context. Use our token calculator to model your specific usage pattern.