Claude Sonnet 4.5 specs, prices, where it runs and its benchmark standing

Name: Claude Sonnet 4.5
Author: Anthropic

closed weights · top 10 on 3 of 12 · released Sep 29, 2025

Provider: Anthropic
Release date: Sep 29, 2025; Boards
Parameters: Not disclosed by Anthropic
Modalities: Text, Image, Files to Text; OpenRouter
License: Proprietary; LMArena
Context window: 1M tokens; Pricing
Pricing: $3 in / $15 out per 1M tokens; All prices
Hosting: 7 priced API routes · AWS Bedrock (35 regions) · OpenRouter; Pricing Regions
Weights: Closed weights
Benchmarks: 12 boards captured

Rank	Board	Category	Score	Of
23	HLEReasoning · as “claude-sonnet-4-5-20250929-thinking”	Reasoning	13.7%	44
25	MultiChallengeChat · as “claude-sonnet-4-5-20250929-thinking”	Chat	55.3%	35
30	Document ArenaVision · as “Claude Sonnet 4.5 (20250929)”	Vision	1,448	40
31	Search ArenaAgents and tools · as “Claude Sonnet 4.5 (Search)”	Agents and tools	1,175	40
31	MCP AtlasAgents and tools · as “claude-sonnet-4-5 (thinking)”	Agents and tools	59.5%	37
55	ARC-AGI-2Reasoning · as “Claude Sonnet 4.5 (Thinking 32K)”	Reasoning	13.6%	92
56	Text ArenaChat · as “Claude Sonnet 4.5 (High, 32K, 20250929)”	Chat	1,456	84
73	Epoch ECIReasoning · as “Claude Sonnet 4.5”	Reasoning	147.6	100
86	GPQA DiamondReasoning · as “claude-sonnet-4-5-20250929_59K”	Reasoning	82.3%	100
2	BFCLAgents and tools · stale since 2026-04-12 · as “Claude-Sonnet-4-5-20250929 (FC)”	Agents and tools	73.2%	81
9	SWE-bench VerifiedCoding · stale since 2026-02-26 · as “Claude 4.5 Sonnet (high)”	Coding	71.4%	39
10	MMLU-ProReasoning · stale since 2026-03-11 · as “Claude-4.5-Sonnet(Thinking)”	Reasoning	87.4%	100

Versions and release history

7 versions in this line since Feb 24, 2025, from Pricing, OpenRouter and the boards.

Category ranks, more models and catalog changes