Claude Sonnet 5.5 handles everyday coding, tool-based workflows, visual analysis, and polished writing with a 1M-token context window. This version skips up-front thinking and can reason between tool calls for faster responses; use Thinking for deeper planning and complex problems.
Added Sep 28, 2026
Context Window
1M
Max Output
128K
Input Price (Auto)
$2.00/1M
Output Price (Auto)
$10.00/1M
Cache Read (Auto)
$0.20/1M
Capabilities
Benchmarks
Benchmarks
Performance metrics and benchmarks
Sourced from Artificial Analysis.
Intelligence Index
56.0
Agentic work
AutomationBench-AA
Workflow automation with guardrail penalties
71.3%
Better than 99% of models compared
AutomationBench-AA Tasks Completed
Fully completed workflows without guardrail violations
44.7%
Better than 97% of models compared
Harvey LAB-AA
Legal agentic work criterion pass rate
93.1%
Better than 89% of models compared
AA-Briefcase
Agentic knowledge work (Elo)
1811 Elo
Better than 99% of models compared
GDPval-AA v2
Economically valuable tasks (Elo)
1844 Elo
Better than 99% of models compared
Document reasoning
GDP.pdf
Professional PDF reasoning: all-pass rate
25.8%
Better than 89% of models compared
AA-LCR v1.1
Long context reasoning with updated grading
82.7%
Better than 95% of models compared
Reasoning
HLE
Humanity's Last Exam
55.0%
Better than 99% of models compared
Coding
Terminal-Bench v4.0
Practical coding and terminal tasks
63.6%
Better than 99% of models compared
SciCode
Python programming for scientific computing
61.0%
Better than 98% of models compared
Legacy benchmarks
AA-LCR (unversioned / legacy)
Long context reasoning evaluation
82.7%
Better than 95% of models compared
Last updated Sep 28, 2026
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