Claude Sonnet 5.5
by Anthropictext+image+file->text8 endpoints
Neura Intelligence Index
99.0/ 100
Rank
#3—
Confidence
lowBenchmarks
1(3% coverage)
Overview
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade. It is especially strong at building features, fixing bugs, and producing polished documents, slides, and spreadsheets, and it writes and communicates more clearly than its predecessor.
Thinking is always on, so effort is the main lever for trading off depth, latency, and cost, and lower effort settings keep it responsive for everyday agentic loops.
Capabilities
Text generation
Image understanding
Tool use / Function calling
Structured output
Extended reasoning
Prompt caching
Long context
File input
Stop sequences
Modalities
Input
TextImageFile
Output
Text
Technical Specifications
Context Window
1M tokens
Max Output
128K tokens
Tokenizer
Claude
Uptime (24h)
10000.0%
Country
🇺🇸US
Release Date
September 28, 20263w
Supported Parameters
include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstool_choicetoolsverbosity
Performance Over Time
Pricing
Per 1M tokens
Input$2.00
Output$10.00
Cache read$0.10
Cache write$2.50
Added
September 28, 2026
Last synced 10/23/2026