Claude 3.5 Sonnet vs Claude Sonnet 4
Claude Sonnet 4 leads the LLM Stats Score 24.2 to 19.1. Claude 3.5 Sonnet and Claude Sonnet 4 cost the same.
Anthropic · Anthropic · Updated for 2026
Which is better?
Claude Sonnet 4 leads the overall LLM Stats Score 24.2 to 19.1, ranking #164 overall.
In the 5 individual benchmarks reported for both models, Claude Sonnet 4 wins 5; this is a narrower head-to-head signal than the composite indexes.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude 3.5 Sonnet
- you want predictable pricing at $3.00/M input and $15.00/M output
Choose Claude Sonnet 4
- overall performance matters — it scores 24.2 and ranks #164 on LLM Stats
- you value its reported benchmark strengths — it wins 5 of 5 exact shared results
- you want the most recent training data — it shipped May 2025
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
19 reported for Claude 3.5 Sonnet · 8 for Claude Sonnet 4
Claude 3.5 Sonnet outperforms in 0 benchmarks, while Claude Sonnet 4 is better at 5 benchmarks (GPQA, MMMU, SWE-Bench Verified, TAU-bench Airline, TAU-bench Retail).
Claude Sonnet 4 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude 3.5 Sonnet ($3.00/1M tokens) costs the same as Claude Sonnet 4 ($3.00/1M tokens).
For output processing, Claude 3.5 Sonnet ($15.00/1M tokens) costs the same as Claude Sonnet 4 ($15.00/1M tokens).
In conclusion, Claude 3.5 Sonnet and Claude Sonnet 4 cost the same.*
* 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. Claude 3.5 Sonnet can generate longer responses up to 200,000 tokens, while Claude Sonnet 4 is limited to 64,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude 3.5 Sonnet and Claude Sonnet 4 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude 3.5 Sonnet
Claude Sonnet 4
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 3.5 Sonnet was released on 2024-10-22, while Claude Sonnet 4 was released on 2025-05-22.
Claude Sonnet 4 is 7 months newer than Claude 3.5 Sonnet.
Oct 22, 2024
1.9 years ago
May 22, 2025
1.3 years ago
7mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Claude 3.5 Sonnet is available from Anthropic, Bedrock, Google. Claude Sonnet 4 is available from Anthropic, Bedrock, Google.
Claude 3.5 Sonnet
Claude Sonnet 4
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude 3.5 Sonnet and Claude Sonnet 4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude 3.5 Sonnet vs Claude Sonnet 4.