Model Comparison

Claude Sonnet 4 vs Claude 3.5 SonnetWhich is better in 2026?

Claude Sonnet 4 significantly outperforms across most benchmarks. Claude Sonnet 4 and Claude 3.5 Sonnet cost the same.

Verdict: Claude Sonnet 4 vs Claude 3.5 Sonnet — which is better?

Claude Sonnet 4 (by Anthropic) and Claude 3.5 Sonnet (by Anthropic) 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 outperforms in 1 benchmarks (GPQA), while Claude 3.5 Sonnet is better at 0 benchmarks. Claude Sonnet 4 significantly outperforms across most benchmarks.

Choose Claude Sonnet 4 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you want the most recent training data — it shipped May 2025

Choose Claude 3.5 Sonnet if…

  • you want predictable pricing at $3.00/M input and $15.00/M output

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Sonnet 4 outperforms in 1 benchmarks (GPQA), while Claude 3.5 Sonnet is better at 0 benchmarks.

Claude Sonnet 4 significantly outperforms across most benchmarks.

Wed Jul 15 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

For input processing, Claude Sonnet 4 ($3.00/1M tokens) costs the same as Claude 3.5 Sonnet ($3.00/1M tokens).

For output processing, Claude Sonnet 4 ($15.00/1M tokens) costs the same as Claude 3.5 Sonnet ($15.00/1M tokens).

In conclusion, Claude Sonnet 4 and Claude 3.5 Sonnet cost the same.*

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

Lowest available price from all providers
Wed Jul 15 2026 • llm-stats.com
Anthropic
Claude Sonnet 4
Input tokens$3.00
Output tokens$15.00
Best providerAnthropic
Anthropic
Claude 3.5 Sonnet
Input tokens$3.00
Output tokens$15.00
Best providerAWS Bedrock
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Both models have the same input context window of 200,000 tokens. Claude 3.5 Sonnet can generate longer responses up to 200,000 tokens, while Claude Sonnet 4 is limited to 64,000 tokens.

Anthropic
Claude Sonnet 4
Input200,000 tokens
Output64,000 tokens
Anthropic
Claude 3.5 Sonnet
Input200,000 tokens
Output200,000 tokens
Wed Jul 15 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Sonnet 4 and Claude 3.5 Sonnet support multimodal inputs.

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

Claude Sonnet 4

Text
Images
Audio
Video

Claude 3.5 Sonnet

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

Proprietary

Closed source

Claude 3.5 Sonnet

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 4 was released on 2025-05-22, while Claude 3.5 Sonnet was released on 2024-06-21.

Claude Sonnet 4 is 11 months newer than Claude 3.5 Sonnet.

Claude Sonnet 4

May 22, 2025

1.1 years ago

11mo newer
Claude 3.5 Sonnet

Jun 21, 2024

2.1 years ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Sonnet 4 is available from Anthropic, Bedrock, Google. Claude 3.5 Sonnet is available from Bedrock, Google.

Claude Sonnet 4

anthropic logo
Anthropic
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
bedrock logo
AWS Bedrock
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
google logo
Google
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

Claude 3.5 Sonnet

bedrock logo
AWS Bedrock
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
google logo
Google
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Higher GPQA score (75.4% vs 59.4%)
Anthropic

No standout differentiators in the data we have for this pair.

AnthropicClaude Sonnet 4
AnthropicClaude 3.5 Sonnet
Compare in Playground

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Sonnet 4 and Claude 3.5 Sonnet side-by-side, then vote on the output you prefer.

Claude Sonnet 4
✓ Preferred
Claude 3.5 Sonnet
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Sonnet 4
Anthropic
Claude 3.5 Sonnet

FAQ

Common questions about Claude Sonnet 4 vs Claude 3.5 Sonnet.

Which is better, Claude Sonnet 4 or Claude 3.5 Sonnet?

Claude Sonnet 4 significantly outperforms across most benchmarks. Claude Sonnet 4 is made by Anthropic and Claude 3.5 Sonnet is made by Anthropic. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Sonnet 4 compare to Claude 3.5 Sonnet in benchmarks?

Claude Sonnet 4 scores MMMLU: 86.5%, TAU-bench Retail: 80.5%, GPQA: 75.4%, MMMU: 74.4%, SWE-Bench Verified: 72.7%. Claude 3.5 Sonnet scores GSM8k: 96.4%, BIG-Bench Hard: 93.1%, HumanEval: 92.0%, MGSM: 91.6%, MMLU: 90.4%.

Is Claude Sonnet 4 cheaper than Claude 3.5 Sonnet?

Both models cost $3.00 per million input tokens.

What are the context window sizes for Claude Sonnet 4 and Claude 3.5 Sonnet?

Claude Sonnet 4 supports 200K tokens and Claude 3.5 Sonnet supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

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