Claude Sonnet 5.5

Anthropic · Big, capable everyday models that cost less than the flagships.

B1 · Heavyweightlegendary

Intelligence ▲ higher wins
Intelligence Index: a composite score from 10 hard evaluations covering reasoning, knowledge, coding, agents and science.
56.0
beats 97% of deck
Hallucination ▼ lower wins
Hallucination rate: of the questions a model gets wrong, how often it confidently makes up an answer instead of saying it doesn't know. Lower wins.
47 %
beats 61% of deck
Context ▲ higher wins
Context window: how many tokens of input the model can consider at once.
1M
beats 65% of deck
Knowledge ▲ higher wins
Training-data cutoff: the most recent month the model learned about. Later wins. N/D means the lab hasn't disclosed it, and an N/D card loses this stat.
Jun 2026
beats 92% of deck
Speed ▲ higher wins
Median output speed in tokens per second, measured on the labs' own APIs.
141 tok/s
beats 65% of deck
Response ▼ lower wins
End-to-end response time: seconds to receive a 500-token answer, thinking time included. Lower wins.
491 s
beats 3% of deck
Price ▼ lower wins
Blended price per million tokens (3:1 input to output). Lower wins.
$4.00
beats 21% of deck
Modalities ▲ higher wins
Number of supported input and output modalities: text, image, audio and video.
3
beats 45% of deck