Model
Model explorer

Claude Sonnet 4.5

CLOSED
Anthropic · Claude 4 family · released Sep 29, 2025

Best coding/agent Sonnet at release, reported to sustain focus on complex tasks for 30+ hours.

ReasoningCodingVisionFunction callingTool useAgentic
1905.6
Elo · rank #94
Parameters
Undisclosed
Active params
—
Context
200K tokens
Architecture
Dense transformer, hybrid-reasoning (parameter count undisclosed)
License
Proprietary
Languages
—
API price (in/out)
$3 / $15
Modalities
text · vision
Benchmark results
Bar shows position within the tracked field; marker = field best
AIMEMath87.0%#59
best: GPT-5.2 · 100.0%
ARC-AGI-2Reasoning13.6%#41
best: GPT-6 Astra · 95.0%
BrowseCompAgents43.9%#39
best: Kimi K3 · 91.2%
CharXivVision67.0%#33
best: Qwen3.8-Flash-Next · 90.6%
GAIAAgents74.5%#2
best: MiniMax-M2 · 75.7%
GDPval-AAAgents1276#33
best: Claude Fable 5 · 1932
GPQA DiamondReasoning83.4%#74
best: GPT-6 Astra · 96.0%
Humanity's Last ExamReasoning33.6%#51
best: Claude Opus 5.5 · 67.7%
LiveCodeBenchCoding73.0%#64
best: DeepSeek-V4-Pro (Think Max) · 93.5%
MMLUKnowledge89.5%#14
best: OpenAI o3 · 92.9%
MMMU-ProVision67.5%#40
best: Claude Opus 4.7 · 85.5%
MMMUVision77.8%#28
best: Claude Fable 5 · 89.3%
OSWorld-VerifiedAgents61.4%#27
best: Claude Fable 5 · 85.0%
SWE-bench VerifiedCoding77.2%#43
best: Claude Opus 5 · 97.0%
τ²-Bench RetailAgents86.2%#4
best: Claude Sonnet 4.6 · 91.7%
τ²-Bench TelecomAgents98.0%#7
best: Claude Opus 4.6 · 99.3%
Terminal-Bench 2.0Coding51.0%#64
best: DeepSeek-V4.1-Flash · 90.6%
Run it locally
Closed weights — available via API only. No local deployment.
Input / M tok
$3
Output / M tok
$15
Claude 4 family
Elo progression across releases
Claude Opus 4May 20251637.6Claude Sonnet 4May 20251533.4Claude Opus 4.1Aug 20251700.2Claude Sonnet 4.5Sep 20251905.6Claude Haiku 4.5Oct 20251518.6Claude Opus 4.5Nov 20252187.9Claude Opus 4.5 (High)Nov 20252220.5Claude Opus 4.5 (Medium)Nov 20252266.8Claude Opus 4.6Feb 20262420.5Claude Sonnet 4.6Feb 20262370.1Claude Opus 4.7Apr 20262650.0Claude Opus 4.8May 20262670.2
Resources
DOCSplatform.claude.comAPIAvailable via Anthropic API
API price $3/$15 · each benchmark row carries its own source badge (see methodology)