Claude 3 Sonnet vs Claude Sonnet 5.5
Claude Sonnet 5.5 leads the LLM Stats Score 51.5 to 1.7. Claude Sonnet 5.5 is 1.5x cheaper per token.
Anthropic · Anthropic · Updated for 2026
Which is better?
Claude Sonnet 5.5 leads the overall LLM Stats Score 51.5 to 1.7, ranking #12 overall.
On price, Claude Sonnet 5.5 is roughly 1.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Claude Sonnet 5.5 also accepts a larger context window (1,000,000 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 3 Sonnet
- you want predictable pricing at $3.00/M input and $15.00/M output
Choose Claude Sonnet 5.5
- overall performance matters — it scores 51.5 and ranks #12 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- cost matters — it's about 1.5x cheaper per token
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Sep 2026
At a glance
The differences that matter most.
Individual benchmarks
11 reported for Claude 3 Sonnet · 8 for Claude Sonnet 5.5
Claude 3 Sonnet and Claude Sonnet 5.5don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude 3 Sonnet ($3.00/1M tokens) is 1.5x more expensive than Claude Sonnet 5.5 ($2.00/1M tokens).
For output processing, Claude 3 Sonnet ($15.00/1M tokens) is 1.5x more expensive than Claude Sonnet 5.5 ($10.00/1M tokens).
In conclusion, Claude 3 Sonnet is more expensive than Claude Sonnet 5.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Claude Sonnet 5.5 accepts 1,000,000 input tokens compared to Claude 3 Sonnet's 200,000 tokens. Claude 3 Sonnet can generate longer responses up to 200,000 tokens, while Claude Sonnet 5.5 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude 3 Sonnet and Claude Sonnet 5.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude 3 Sonnet
Claude Sonnet 5.5
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 Sonnet was released on 2024-02-29, while Claude Sonnet 5.5 was released on 2026-09-28.
Claude Sonnet 5.5 is 31 months newer than Claude 3 Sonnet.
Feb 29, 2024
2.6 years ago
Sep 28, 2026
-2 days ago
2.6yr newerKnowledge Cutoff
When training data ends
Claude Sonnet 5.5 has a documented knowledge cutoff of 2026-06-01, while Claude 3 Sonnet's cutoff date is not specified.
We can confirm Claude Sonnet 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Claude 3 Sonnet's cutoff date.
—
Jun 2026
Provider Availability
Claude 3 Sonnet is available from Anthropic, Bedrock, Google. Claude Sonnet 5.5 is available from Anthropic.
Claude 3 Sonnet
Claude Sonnet 5.5
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude 3 Sonnet and Claude Sonnet 5.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude 3 Sonnet vs Claude Sonnet 5.5.