GPT-5.1 vs Claude Sonnet 4.5: Pricing Comparison
Compare pricing, capabilities, and costs for your LLM workloads.
OpenAI
GPT-5.1
Pricing (per 1M tokens)
Input$1.25
Output$10.00
Cached Input$0.1250
Context & Output
Context Window400K tokens
Max Output128K tokens
Capabilities
Categoryflagship
Multimodaltext + image
Fine-tuningNo
StreamingYes
Anthropic
Claude Sonnet 4.5
Pricing (per 1M tokens)
Input$3.00
Output$15.00
Cached Input$0.3000
Batch Input$1.50
Batch Output$7.50
Context & Output
Context Window200K tokens
Max Output64K tokens
Capabilities
Categorymid
Multimodaltext + image
Fine-tuningNo
StreamingYes
Quick Verdict
Cheaper Input Price
GPT-5.1
58.3% cheaper
Cheaper Output Price
GPT-5.1
33.3% cheaper
Larger Context Window
GPT-5.1
+200K tokens
Cost Comparison
Sample workload: 1,000,000 input tokens + 1,000,000 output tokens
GPT-5.1
$11.25
$1.25/1M input + $10.00/1M output
Claude Sonnet 4.5
$18.00
$3.00/1M input + $15.00/1M output
GPT-5.1 is 37.5% cheaper for this workload.
Frequently Asked Questions
Which is cheaper, GPT-5.1 or Claude Sonnet 4.5?
For input tokens, GPT-5.1 is cheaper at $1.25 per 1M tokens. For output tokens, GPT-5.1 is cheaper at $10.00 per 1M tokens. The overall cost depends on your workload's input/output ratio.
What is the context window size of GPT-5.1 vs Claude Sonnet 4.5?
GPT-5.1 has a context window of 400K tokens, while Claude Sonnet 4.5 has 200K tokens. GPT-5.1 supports a larger context window of 400K tokens, which is beneficial for processing longer documents.
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