Claude Opus 4.5 vs o3
Claude Opus 4.5 significantly outperforms across most benchmarks. o3 is 2.9x cheaper per token.
Anthropic · OpenAI · Updated for 2026
Which is better?
Claude Opus 4.5 outperforms in 5 benchmarks (ARC-AGI v2, GPQA, SWE-Bench Verified, Tau2 Retail, Tau2 Telecom), while o3 is better at 0 benchmarks. Claude Opus 4.5 significantly outperforms across most benchmarks.
On price, o3 is roughly 2.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Based on current benchmark, pricing, and model metadata for 2026.
Choose Claude Opus 4.5
- you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
- you want the most recent training data — it shipped Nov 2025
Choose o3
- cost matters — it's about 2.9x cheaper per token
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
Claude Opus 4.5 outperforms in 5 benchmarks (ARC-AGI v2, GPQA, SWE-Bench Verified, Tau2 Retail, Tau2 Telecom), while o3 is better at 0 benchmarks.
Claude Opus 4.5 significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 2.5x more expensive than o3 ($2.00/1M tokens).
For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 3.1x more expensive than o3 ($8.00/1M tokens).
In conclusion, Claude Opus 4.5 is more expensive than o3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 200,000 tokens. o3 can generate longer responses up to 100,000 tokens, while Claude Opus 4.5 is limited to 64,000 tokens.
Input Capabilities
Supported data types and modalities
Both Claude Opus 4.5 and o3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Opus 4.5
o3
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Opus 4.5 was released on 2025-11-24, while o3 was released on 2025-04-16.
Claude Opus 4.5 is 7 months newer than o3.
Nov 24, 2025
9 months ago
7mo newerApr 16, 2025
1.4 years ago
Knowledge Cutoff
When training data ends
Claude Opus 4.5 has a knowledge cutoff of 2025-03-31, while o3 has a cutoff of 2024-05-31.
Claude Opus 4.5 has more recent training data (up to 2025-03-31), making it potentially better informed about events through that date compared to o3 (2024-05-31).
Mar 2025
10 mo newerMay 2024
Provider Availability
Claude Opus 4.5 is available from Anthropic. o3 is available from OpenAI.
Claude Opus 4.5
o3
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Opus 4.5 and o3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Opus 4.5 vs o3.