Identity
- Status
- active
- Developer ID
claude-sonnet-4-5- Released
- Sep 29, 2025
- Version
- Claude Sonnet 4.5
- License
- Unknown
AnthropicClaude Sonnet 4.5
Claude Sonnet 4.5 is an Anthropic Claude model for reasoning, coding, multimodal analysis, and tool-using agents.
- Token context
- 200K tokens
- Inputs
- Text, Image
- Outputs
- Text
- Released
- Sep 29, 2025
Providers & Pricing
Estimate workload cost →| Provider | Input / 1M | Output / 1M | Cache read / 1M | Cache write / 1M | Observed | Evidence |
|---|---|---|---|---|---|---|
AnthropicAvailable | $3.00 | $15.00 | $0.30 | — | Sep 3, 2026 | Provider-reported |
Benchmarks
All benchmark results →| ARC-AGI-1verified-v1-302d8267c052 | 63.67 | — | — | Claude Sonnet 4.5 (Thinking 32K)unknown | Original sourcewinner eligible | Third-party benchmark |
| ARC-AGI-2verified-v2-bca68e12cc9a | 13.61 | — | — | Claude Sonnet 4.5 (Thinking 32K)unknown | Original sourcewinner eligible | Third-party benchmark |
| Berkeley Function Calling Leaderboardv4-ede5081a24bc | 73.24 | — | — | Claude-Sonnet-4-5-20250929 (FC)unknown | Recomputedwinner eligible | Third-party benchmark |
| Berkeley Function Calling Leaderboardv4-ede5081a24bc | 24.90 | — | — | Claude-Sonnet-4-5-20250929 (Prompt)unknown | Recomputedwinner eligible | Third-party benchmark |
| LMArena Document Arenadocument-2026-09-13-a64ca3b12b6e | 1,449.81 | — | 31,455 | claude-sonnet-4-5-20250929; 95% CI [1443.68972646, 1455.92640287]; votes 31455; rank 28unknown | Original sourcewinner eligible | Third-party benchmark |
| LMArena Search Arenasearch-2026-10-13-a64ca3b12b6e | 1,160.27 | — | 144,153 | claude-sonnet-4-5-search; 95% CI [1155.14751166, 1165.38826265]; votes 144153; rank 31unknown | Original sourcewinner eligible | Third-party benchmark |
| LMArena Text Arenatext-2026-10-15-a64ca3b12b6e | 1,438.42 | — | 82,688 | claude-sonnet-4-5-20250929; 95% CI [1435.57332334, 1441.27604162]; votes 82688; rank 79unknown | Original sourcewinner eligible | Third-party benchmark |
| LMArena Text Arenatext-2026-10-15-a64ca3b12b6e | 1,434.58 | — | 83,940 | claude-sonnet-4-5-20250929-high-32k; 95% CI [1431.82164426, 1437.34230911]; votes 83940; rank 88unknown | Original sourcewinner eligible | Third-party benchmark |
At a Glance
Model Facts
Capacity
- Token context
- 200K tokens
- Maximum output
- 64K tokens
- Total parameters
- Unknown
- Active parameters
- Unknown
- Knowledge cutoff
- Jan 1, 2025
Interface and Access
- Inputs
- Text, Image
- Outputs
- Text
- API available
- Yes
- Open weights
- No
- Self-hostable
- No
- Reasoning
- Yes
- Vision
- Yes
- Tool calling
- Yes
- Capabilities
- chat, generation, reasoning, structured outputs, tools
This page represents one developer model product. Dated API snapshots, serving endpoints, pricing, regions, quantizations, and service tiers attach as versioned aliases or provider details and never create duplicate public model records.
Version Lineage
PredecessorUnknown
SuccessorsUnknown
Aliasesclaude-sonnet-4-5, claude-sonnet-4-5-20250929
Explicit Unknowns
- Architecture
- Tokenizer
Primary Evidence
Sources and Observation Date
Comparable Peers
Related Model Comparisons
| A | Pair | B | Context |
|---|---|---|---|
Claude Sonnet 4.5Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs | Claude Haiku 4.5Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs | Claude Opus 4.5Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs | Claude Sonnet 4.6Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs |  GPT-5 NanoOpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | GPT-5 ProOpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | GPT-5.1OpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | GPT-5.2OpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | GPT-5.2 ProOpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | o3OpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | o3-proOpenAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs |  Qwen3 VL FlashQwen | cross-developer peersimage, text |
Questions
Claude Sonnet 4.5 FAQs
What is Claude Sonnet 4.5?+
Claude Sonnet 4.5 is an Anthropic Claude model for reasoning, coding, multimodal analysis, and tool-using agents. It is developed by Anthropic and its current sourced lifecycle status is active.
What inputs and outputs does Claude Sonnet 4.5 support?+
Claude Sonnet 4.5's current record lists Text and Image as input and Text as output.
How much context does Claude Sonnet 4.5 support?+
The current record lists a 200K-token context window and a maximum output of 64K tokens.
Is Claude Sonnet 4.5 available through an API?+
Claude Sonnet 4.5 is marked as API-available. The directly sourced provider records currently include Anthropic.
How much does Claude Sonnet 4.5 cost through an API?+
The lowest directly sourced prices currently attached to Claude Sonnet 4.5 are $3.00 per million input tokens through Anthropic and $15.00 per million output tokens through Anthropic. Prices are provider-specific and should be checked against each cited observation date.
What capabilities and tasks does Claude Sonnet 4.5 support?+
Claude Sonnet 4.5's recorded capabilities are chat, generation, reasoning, structured outputs, and tools. Its supported tasks are image, reasoning, and text.
Can Claude Sonnet 4.5 be self-hosted?+
Claude Sonnet 4.5 is not marked as an open-weight model. Self-hosting is marked as unsupported, with no license recorded.
Does Claude Sonnet 4.5 have related versions or aliases?+
No predecessor is recorded. No successor is recorded. Recorded aliases are claude-sonnet-4-5 and claude-sonnet-4-5-20250929.
Which models can Claude Sonnet 4.5 be compared with?+
The current compatible peer set includes Claude Sonnet 5, Claude Haiku 4.5, Claude Opus 4.5, Claude Sonnet 4.6, and GPT-5 Nano. Compatibility requires shared sourced modalities and tasks; it does not imply that one model is better. Browse model comparisons →
How current is the Model Markets record for Claude Sonnet 4.5?+
Claude Sonnet 4.5 was last verified Sep 3, 2026 from Anthropic's primary source, “Claude Sonnet 4.5 | Claude Platform Docs.” The evidence is classified as official fact.