AnthropicUnited States· released Sep 2026
Claude Sonnet 5.5
Listed, waiting for its first published score.
Anthropic, United States. One of 15 models from this lab on the Index.
Available in Theo as Theo Think and Theo Saga 2.0
Theo orchestrates it for the steps it does best and always shows which engine answered.
Snapshot September 8, 2026
OpenCharts Index
—
No published score matched yet
Needs more results (0 of 8 so far)
Distance to today's frontier on the hardest tests. Not a measure of intelligence.
Scores
Every test, every source
The best published run per benchmark, the raw value as the publisher reports it, who produced the number, how close it comes to the best published result on that test, and where the model sits among every model scored on it. Percent scores are read above chance, Arena ratings as a win rate against the board leader, open-ended values on a log scale. A test with too few models to compare against is shown but not counted.
No published score has matched this model yet. It appears here so a future refresh can pick it up.
Top of the leaderboard
Compare with its neighbours.
The best models, ranked here, working inside Theo.
25 of the models on this page run inside Theo today. Theo picks the right one for each step and always shows which engine answered.