Which model is better: Claude 4.5 Sonnet or OpenAI o3?
OpenAI o3 is 33.3% cheaper for input tokens ($2.00 vs. $3.00 per 1M tokens) and $8.00 vs. $15.00 for output tokens (1.5x cost advantage). In terms of operational performance, Claude 4.5 Sonnet delivers lower response latency at 380ms TTFT (770ms faster than OpenAI o3) with 84 vs. 82 tok/s throughput. Claude 4.5 Sonnet leads coding evaluations at 75.8% SWE-bench Verified vs. 71.7% for OpenAI o3 and 84.2% vs. 87.7% on GPQA Diamond.
Verified daily via automated API latency tests and official documentation.
Zero-Shot RAG Verified
Verified Performance & Unit Economics Delta (12 Dimensions)
Daily synchronized metrics across token pricing, prompt cache economics, latency, throughput, and 5 capability benchmarks.
Metric / Dimension
Claude 4.5 Sonnet
OpenAI o3
Net Delta / Advantage
Input Cost / 1M Tokens
$3.00
$2.00
OpenAI o3 is 1.5x cheaper
Output Cost / 1M Tokens
$15.00
$8.00
OpenAI o3 (46.7% lower)
Prompt Cache Read / 1M
$0.300
$0.500
Claude 4.5 Sonnet is 1.7x cheaper
Prompt Cache Write / 1M
$3.75
$2.00
OpenAI o3 is 1.9x cheaper
Context Window (Max Output)
205k (64k out)
205k (100k out)
Equal Context Window
Avg TTFT Response Latency
380ms
1150ms
Claude 4.5 Sonnet (770ms faster)
Generation Speed (Throughput)
84 tok/s
82 tok/s
Claude 4.5 Sonnet (+2 tok/s faster)
SWE-bench Verified (Coding)
75.8%
71.7%
Claude 4.5 Sonnet (+4.1% lead)
GPQA Diamond (PhD STEM)
84.2%
87.7%
OpenAI o3 (+3.5% lead)
MMLU-Pro (Multi-Discipline)
90.4%
89.8%
Claude 4.5 Sonnet (+0.6% lead)
MATH-500 (Quantitative Logic)
97.5%
98.6%
OpenAI o3 (+1.1% lead)
Inference Value Score (IVR)
56.5 / 100
60.6 / 100
OpenAI o3 (+4.1 pts)
Interactive Monthly Token Economics & ROI Forecaster
Model production workloads across prompt, completion, and cached context tokens, or switch models on the fly.
OpenAI o3 is cheaper at $2.00/1M input tokens ($8.00/1M output) compared to $3.00/1M input ($15.00/1M output) for Claude 4.5 Sonnet.
Which model has lower TTFT latency and higher tok/s throughput: Claude 4.5 Sonnet or OpenAI o3?
Claude 4.5 Sonnet delivers faster first-token latency at 380ms TTFT (84 tok/s throughput) compared to 1150ms TTFT (82 tok/s) for OpenAI o3.
How do Claude 4.5 Sonnet and OpenAI o3 compare on SWE-bench coding and GPQA Diamond reasoning?
On SWE-bench Verified software engineering, Claude 4.5 Sonnet scores 75.8% versus 71.7% for OpenAI o3. On GPQA Diamond graduate-level STEM reasoning, Claude 4.5 Sonnet scores 84.2% versus 87.7% for OpenAI o3 (and 97.5% vs 98.6% on MATH-500).
When should you choose Claude 4.5 Sonnet?
Choose Claude 4.5 Sonnet (Anthropic) for end-to-end autonomous coding agents, complex multi-file debugging, browser/GUI automation, and high-precision technical writing — offering a 204k context window, 380ms TTFT, and $3.00/1M input pricing ($0.300/1M cached reads).
When should you choose OpenAI o3?
Choose OpenAI o3 (OpenAI) for algorithmic synthesis, mathematical verification, PhD-level scientific research, and multi-step tool planning — offering a 204k context window, 1150ms TTFT, and $2.00/1M input pricing ($0.500/1M cached reads).
