Frontier models

Claude Sonnet 5

Claude Sonnet 5 is Anthropic’s speed-and-intelligence balance model for everyday coding and agents. The API id is claude-sonnet-5. Pricing is $2 input and $10 output per million tokens.

Status: Archived
Price: $2 in, $10 outUS dollars per million tokens (word pieces) in and out, unless noted

Training

Anthropic lists a reliable knowledge and training data cutoff of January 2026. Parameter count, training FLOPs, and the full post-training recipe for this SKU are not published on the models overview or choosing guide.

Inference

Adaptive thinking is supported. Default effort is high. Relative to the current Claude lineup, Sonnet is the fast latency class.

Context

The documented context window is 1 million tokens. Max output is 128K tokens. Inputs are text and images; output is text. The model supports multilingual use, vision, and tool use.

Methods

Anthropic names an effort parameter and tools for this SKU.

Benchmarking

Anthropic has not published a Sonnet 5 score table on the models overview or the Fable announce pages cited here. The Fable announce table covers Fable and Opus columns, not Sonnet 5.

Hardware

Anthropic trains and runs Claude on AWS Trainium, Google TPUs, and NVIDIA GPUs. Amazon is the primary cloud and training partner. Anthropic reported more than 1 million Trainium2 chips in use as of April 2026. Per-SKU serving silicon is not published. Buyers purchase API tokens, not a named Claude GPU SKU.

Access and pricing

Pricing is $2 input and $10 output per million tokens.