Claude 3 Sonnet vs Step 3.5 Flash
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for Claude 3 Sonnet and Step 3.5 Flash.
Claude 3 Sonnet
Claude 3 Sonnet was Anthropic's balanced standard model in the first Claude 3 generation, optimized for a combination of response speed and general-purpose capabilities across writing, summarization, and question answering. Released in March 2024 alongside Opus and Haiku, it occupied the mid-tier positioning in the Claude 3 lineup. Claude 3 Sonnet has since been deprecated, and current use cases requiring similar capability-to-cost balance are best served by the Claude 4 Sonnet series, which offers substantially improved reasoning, context handling, and instruction following at competitive pricing.
Step 3.5 Flash
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....
Technical Specifications
| Specification | Claude 3 Sonnet | Step 3.5 Flash |
|---|---|---|
| Provider | Anthropic | StepFun |
| Context Window | 200,000 tokens | 262,144 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | N/A | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2024-03-04 | 2026-01-29 |
API Pricing Comparison
Input Price per Million Tokens
Claude 3 Sonnet
$3.00
Step 3.5 Flash
$0.10
Output Price per Million Tokens
Claude 3 Sonnet
$15.00
Step 3.5 Flash
$0.30
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
Claude 3 Sonnet Quirks & Gotchas
No developer gotchas reported.
Step 3.5 Flash Quirks & Gotchas
No developer gotchas reported.