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Claude Sonnet 4.5 vs GPT-5

Claude Sonnet 4.5 and GPT-5 are closely matched at 32.6 and 34.4 on the LLM Stats Score. GPT-5 is 1.7x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Sonnet 4.5 and GPT-5 are closely matched on the overall LLM Stats Score at 32.6 and 34.4.

In the 2 individual benchmarks reported for both models, GPT-5 wins 2; this is a narrower head-to-head signal than the composite indexes.

On price, GPT-5 is roughly 1.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

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

Based on current LLM Stats indexes, shared benchmarks, 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

  • you value its reported benchmark strengths — it wins 2 of 2 exact shared results
  • cost matters — it's about 1.7x cheaper per token
  • you process long inputs — it offers a 400,000 token context window

At a glance

The differences that matter most.

Core performance indexes
32.6
#91
34.4
#81
31.6
#95
34.7
#78
21.6
#75
26.7
#58
19.0
#59
9.6
#114
Cost, coverage & limits
Benchmark wins
0 of 2
2 of 2
Input price
$3.00 / M
$1.25 / M
Output price
$15.00 / M
$10.00 / M
Context window
200,000
400,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

5 shared
Index
Claude Sonnet 4.5
GPT-5
25.1#102
31.3#62
11.5#104
20.9#59
26.2#25
17.9#66
26.5#5
22.7#10
13.1#96
27.3#33
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for Claude Sonnet 4.5 · 34 for GPT-5

2 shared

Claude Sonnet 4.5 outperforms in 0 benchmarks, while GPT-5 is better at 2 benchmarks (AIME 2025, GPQA).

GPT-5 significantly outperforms across most benchmarks.

Fri Aug 28 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-5 costs less

For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) is 2.4x more expensive than GPT-5 ($1.25/1M tokens).

For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) is 1.5x more expensive than GPT-5 ($10.00/1M tokens).

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

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

Lowest available price from all providers
Fri Aug 28 2026 • llm-stats.com
Anthropic
Claude Sonnet 4.5
Input tokens$3.00
Output tokens$15.00
Best providerAnthropic
OpenAI
GPT-5
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

GPT-5 accepts 400,000 input tokens compared to Claude Sonnet 4.5's 200,000 tokens. GPT-5 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
Input400,000 tokens
Output128,000 tokens
Fri Aug 28 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Sonnet 4.5 and GPT-5 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

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

Proprietary

Closed source

Release Timeline

When each model was launched

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

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

Claude Sonnet 4.5

Sep 29, 2025

11 months ago

1mo newer
GPT-5

Aug 7, 2025

1.1 years ago

Knowledge Cutoff

When training data ends

Claude Sonnet 4.5 has a knowledge cutoff of 2025-01-31, while GPT-5 has a cutoff of 2024-09-30.

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 (2024-09-30).

Claude Sonnet 4.5

Jan 2025

4 mo newer
GPT-5

Sep 2024

Provider Availability

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

Claude Sonnet 4.5

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

GPT-5

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M
* 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 side-by-side, then vote on the output you prefer.

Claude Sonnet 4.5
✓ Preferred
GPT-5
Open in Playground

FAQ

Common questions about Claude Sonnet 4.5 vs GPT-5.

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

Claude Sonnet 4.5 and GPT-5 are closely matched on the LLM Stats Score at 32.6 and 34.4. Claude Sonnet 4.5 is made by Anthropic and GPT-5 is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Sonnet 4.5 compare to GPT-5 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 scores SWE-Lancer (IC-Diamond subset): 100.0%, COLLIE: 99.0%, Tau2 Telecom: 96.7%, OpenAI-MRCR: 2 needle 128k: 95.2%, AIME 2025: 94.6%.

Is Claude Sonnet 4.5 cheaper than GPT-5?

GPT-5 is 2.4x cheaper for input tokens. Claude Sonnet 4.5 costs $3.00/M input and $15.00/M output via anthropic. GPT-5 costs $1.25/M input and $10.00/M output via openai.

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

Claude Sonnet 4.5 supports 200K tokens and GPT-5 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?

Key differences include LLM Stats Score (32.6 vs 34.4), context window (200K vs 400K), input pricing ($3.00 vs $1.25/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 4.5 and GPT-5?

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