Model Library
AnthropicReleased September 29, 2025Claude 4.5 Sonnet
Anthropic · Released September 29, 2025
Intelligence score
36
At a glance
- Intelligence
- 36
- Speed
- 48.7tokens/sec
- Latency
- 11.33stime to first token
- Input price
- $3.00per 1M tokens
- Output price
- $15.00per 1M tokens
- Context window
- 5tokens
- Parameters
- —
Summary
Comparison summary
Claude 4.5 Sonnet (Reasoning) scores 36 on the Artificial Analysis Intelligence Index, placing it above average among other reasoning models in a similar price tier (median: 28). Claude 4.5 Sonnet (Reasoning) generates output at 48.7 tokens per second (based on Anthropic's API), which is at the lower end compared to other reasoning models in a similar price tier (median: 81.2 t/s). Claude 4.5 Sonnet (Reasoning) costs $3.00 per 1M input tokens (somewhat higher than average, median: $1.50) and $15.00 per 1M output tokens (somewhat higher than average, median: $8.40), based on Anthropic's API.
Specifications
Technical specifications
| Model name | Claude 4.5 Sonnet |
|---|---|
| Provider | Anthropic |
| Release date | September 29, 2025 |
| Intelligence score | 36 |
| Speed | 48.7 tokens/sec |
| Latency (TTFT) | 11.33s |
| Input price | $3.00 / 1M tokens |
| Output price | $15.00 / 1M tokens |
| Context window | 5 tokens |
| Parameters | — |
| Reasoning | Yes |
| Input modalities | text, image |
| Output modalities | — |
| Open weights | No |
| License | — |
| API availability | — |
| Source | Model Intelligence legacy profile: claude-4-5-sonnet-thinking |
Pricing
Token prices
Price per 1M tokens
Claude 4.5 Sonnet, as listed in the catalog record
- Input$3.00
- Output$15.00
| Token type | Price per 1M |
|---|---|
| Input | $3.00 |
| Output | $15.00 |
Model Intelligence legacy profile: claude-4-5-sonnet-thinking
FAQ · 20
Frequently asked questions
Claude 4.5 Sonnet (Reasoning) was released on September 29, 2025.
Claude 4.5 Sonnet (Reasoning) was created by Anthropic.
Claude 4.5 Sonnet (Reasoning) scores 36 on the Artificial Analysis Intelligence Index, placing it above average among other reasoning models in a similar price tier (median: 28).
Claude 4.5 Sonnet (Reasoning) generates output at 48.7 tokens per second (based on Anthropic's API), which is at the lower end compared to other reasoning models in a similar price tier (median: 81.2 t/s).
Claude 4.5 Sonnet (Reasoning) has a time to first token (TTFT) of 11.33s (based on Anthropic's API), which is somewhat higher than average compared to other reasoning models in a similar price tier (median: 2.77s).
Claude 4.5 Sonnet (Reasoning) costs $3.00 per 1M input tokens (somewhat higher than average, median: $1.50) and $15.00 per 1M output tokens (somewhat higher than average, median: $8.40), based on Anthropic's API.
Claude 4.5 Sonnet (Reasoning) costs $3.00 per 1M input tokens and $15.00 per 1M output tokens (based on Anthropic's API). For a blended rate (7:2:1 cache hit/input/output ratio), this is $2.31 per 1M tokens. Pricing may vary by provider.
When evaluated on the Intelligence Index, Claude 4.5 Sonnet (Reasoning) generated 63M output tokens, which is better than average compared to other reasoning models in a similar price tier (median: 72M).
Yes, Claude 4.5 Sonnet (Reasoning) is a reasoning model. It uses extended thinking or chain-of-thought reasoning to work through complex problems before providing an answer.
Claude 4.5 Sonnet (Reasoning) supports text and image input.
Claude 4.5 Sonnet (Reasoning) supports text output.
Yes, Claude 4.5 Sonnet (Reasoning) supports image input and can analyze, describe, and answer questions about images.
Yes, Claude 4.5 Sonnet (Reasoning) is multimodal. It can process text and image input and generate text output.
Claude 4.5 Sonnet (Reasoning) has a context window of 1.0M tokens. This determines how much text and conversation history the model can process in a single request.
No, Claude 4.5 Sonnet (Reasoning) is proprietary. The model weights are not publicly available.
Claude 4.5 Sonnet (Reasoning) is a proprietary model and Anthropic has not disclosed the model size or parameter count.
Claude 4.5 Sonnet (Reasoning) achieves a score of 36 on the Artificial Analysis Intelligence Index. This composite benchmark evaluates models across reasoning, knowledge, mathematics, and coding.
Claude 4.5 Sonnet (Reasoning) has a knowledge cutoff of July 2025. The model's training data includes information up to this date.
Yes, Claude 4.5 Sonnet (Reasoning) is available via API through 4 providers.
Claude 4.5 Sonnet (Reasoning) is available through 4 API providers.