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Claude Sonnet 4.5 vs GPT-5 mini

Both models are evenly matched across the benchmarks. GPT-5 mini is 8.7x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Sonnet 4.5 outperforms in 1 benchmarks (GPQA), while GPT-5 mini is better at 1 benchmark (AIME 2025). Both models are evenly matched across the benchmarks.

On price, GPT-5 mini is roughly 8.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5 mini also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Claude Sonnet 4.5

  • you want the most recent training data — it shipped Sep 2025

Choose GPT-5 mini

  • cost matters — it's about 8.7x cheaper per token
  • you process long inputs — it offers a 400,000 token context window

At a glance

The differences that matter most.

Claude Sonnet 4.5
Anthropic
GPT-5 mini
OpenAI
Benchmark wins
1 of 2
1 of 2
Input price
$3.00 / M
$0.25 / M
Output price
$15.00 / M
$2.00 / M
Context window
200,000
400,000
Released
Sep 2025
Aug 2025
License
Proprietary
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Sonnet 4.5 outperforms in 1 benchmarks (GPQA), while GPT-5 mini is better at 1 benchmark (AIME 2025).

Both models are evenly matched across the benchmarks.

Wed Aug 26 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

GPT-5 mini costs less

For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) is 12.0x more expensive than GPT-5 mini ($0.25/1M tokens).

For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) is 7.5x more expensive than GPT-5 mini ($2.00/1M tokens).

In conclusion, Claude Sonnet 4.5 is more expensive than GPT-5 mini.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Wed Aug 26 2026 • llm-stats.com
Anthropic
Claude Sonnet 4.5
Input tokens$3.00
Output tokens$15.00
Best providerAnthropic
OpenAI
GPT-5 mini
Input tokens$0.25
Output tokens$2.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5 mini accepts 400,000 input tokens compared to Claude Sonnet 4.5's 200,000 tokens. GPT-5 mini can generate longer responses up to 128,000 tokens, while Claude Sonnet 4.5 is limited to 64,000 tokens.

Anthropic
Claude Sonnet 4.5
Input200,000 tokens
Output64,000 tokens
OpenAI
GPT-5 mini
Input400,000 tokens
Output128,000 tokens
Wed Aug 26 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Sonnet 4.5 and GPT-5 mini support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Sonnet 4.5

Text
Images
Audio
Video

GPT-5 mini

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Sonnet 4.5

Proprietary

Closed source

GPT-5 mini

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 4.5 was released on 2025-09-29, while GPT-5 mini was released on 2025-08-07.

Claude Sonnet 4.5 is 2 months newer than GPT-5 mini.

Claude Sonnet 4.5

Sep 29, 2025

11 months ago

1mo newer
GPT-5 mini

Aug 7, 2025

1.0 years ago

Knowledge Cutoff

When training data ends

Claude Sonnet 4.5 has a knowledge cutoff of 2025-01-31, while GPT-5 mini has a cutoff of 2024-05-30.

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 GPT-5 mini (2024-05-30).

Claude Sonnet 4.5

Jan 2025

8 mo newer
GPT-5 mini

May 2024

Provider Availability

Claude Sonnet 4.5 is available from Anthropic. GPT-5 mini is available from OpenAI.

Claude Sonnet 4.5

anthropic logo
Anthropic
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

GPT-5 mini

openai logo
OpenAI
Input Price:Input: $0.25/1MOutput Price:Output: $2.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Sonnet 4.5 and GPT-5 mini side-by-side, then vote on the output you prefer.

Claude Sonnet 4.5
✓ Preferred
GPT-5 mini
Open in Playground

FAQ

Common questions about Claude Sonnet 4.5 vs GPT-5 mini.

Which is better, Claude Sonnet 4.5 or GPT-5 mini?

Both models are evenly matched across the benchmarks. Claude Sonnet 4.5 is made by Anthropic and GPT-5 mini is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Sonnet 4.5 compare to GPT-5 mini in benchmarks?

Claude Sonnet 4.5 scores MMMLU: 89.1%, AIME 2025: 87.0%, TAU-bench Retail: 86.2%, GPQA: 83.4%, MMMUval: 77.8%. GPT-5 mini scores AIME 2025: 91.1%, HMMT 2025: 87.8%, GPQA: 82.3%, FrontierMath: 22.1%, Humanity's Last Exam: 16.7%.

Is Claude Sonnet 4.5 cheaper than GPT-5 mini?

GPT-5 mini is 12.0x cheaper for input tokens. Claude Sonnet 4.5 costs $3.00/M input and $15.00/M output via anthropic. GPT-5 mini costs $0.25/M input and $2.00/M output via openai.

What are the context window sizes for Claude Sonnet 4.5 and GPT-5 mini?

Claude Sonnet 4.5 supports 200K tokens and GPT-5 mini supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Sonnet 4.5 and GPT-5 mini?

Key differences include context window (200K vs 400K), input pricing ($3.00 vs $0.25/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 4.5 and GPT-5 mini?

Claude Sonnet 4.5 is developed by Anthropic and GPT-5 mini is developed by OpenAI.

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