Model Comparison
Claude Sonnet 4.5 vs o4-miniWhich is better in 2026?
Claude Sonnet 4.5 shows notably better performance in the majority of benchmarks. o4-mini is 3.1x cheaper per token.
Verdict: Claude Sonnet 4.5 vs o4-mini — which is better?
Claude Sonnet 4.5 (by Anthropic) and o4-mini (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Claude Sonnet 4.5 outperforms in 3 benchmarks (GPQA, TAU-bench Airline, TAU-bench Retail), while o4-mini is better at 1 benchmark (AIME 2025). Claude Sonnet 4.5 shows notably better performance in the majority of benchmarks.
On price, o4-mini is roughly 3.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Choose Claude Sonnet 4.5 if…
- you want the strongest raw capability — it leads on 3 of 4 shared benchmarks
- you want the most recent training data — it shipped Sep 2025
Choose o4-mini if…
- cost matters — it's about 3.1x cheaper per token
Performance Benchmarks
Comparative analysis across standard metrics
Claude Sonnet 4.5 outperforms in 3 benchmarks (GPQA, TAU-bench Airline, TAU-bench Retail), while o4-mini is better at 1 benchmark (AIME 2025).
Claude Sonnet 4.5 shows notably better performance in the majority of benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) is 2.7x more expensive than o4-mini ($1.10/1M tokens).
For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) is 3.4x more expensive than o4-mini ($4.40/1M tokens).
In conclusion, Claude Sonnet 4.5 is more expensive than o4-mini.*
* 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. o4-mini can generate longer responses up to 100,000 tokens, while Claude Sonnet 4.5 is limited to 64,000 tokens.
Input Capabilities
Supported data types and modalities
Both Claude Sonnet 4.5 and o4-mini support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Sonnet 4.5
o4-mini
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 Sonnet 4.5 was released on 2025-09-29, while o4-mini was released on 2025-04-16.
Claude Sonnet 4.5 is 6 months newer than o4-mini.
Sep 29, 2025
9 months ago
5mo newerApr 16, 2025
1.2 years ago
Knowledge Cutoff
When training data ends
Claude Sonnet 4.5 has a knowledge cutoff of 2025-01-31, while o4-mini has a cutoff of 2024-05-31.
Claude Sonnet 4.5 has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to o4-mini (2024-05-31).
Jan 2025
8 mo newerMay 2024
Provider Availability
Claude Sonnet 4.5 is available from Anthropic. o4-mini is available from OpenAI.
Claude Sonnet 4.5
o4-mini
Outputs Comparison
Key Takeaways
Claude Sonnet 4.5
View detailsAnthropic
o4-mini
View detailsOpenAI
Claude Sonnet 4.5o4-miniDetailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Claude Sonnet 4.5 and o4-mini side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Claude Sonnet 4.5 vs o4-mini.