Pelicans riding bicycles for Haiku at the different thinking levels: https://tools.simonwillison.net/markdown-svg-renderer?url=ht...
Low messes up the bicycle frame, but medium/high/xhigh/max all get the bicycle frame right.
The max one took 5 minutes 9 seconds and cost 3.3826 cents. The cheapest one (low) cost 0.0936 cents and took 7 seconds.
The most recent release of my llm-anthropic plugin queries the Anthropic model listing API directly, so I didn't have to upgrade the plugin to add support for this model:
llm install llm-anthropic -U
llm anthropic refresh
llm -m claude-haiku-5.5 'prompt goes here'
EDIT: Here's the Haiku 4.5 pelican from a year ago for comparison, it was terrible: https://simonwillison.net/2025/Oct/15/claude-haiku-45/Of course, the sun again. Everyone knows that a pelican can't ride a bicycle without a sun in the frame and can only go right.
I'm still getting network errors. Seems to be CORS-related.
I find it helpful when you post your link that compares the model to other models in the same class or family, or shows progression over time.
The pelicans all start to look the same after a while.
But seeing the comparison to other models by class, family, or historical progression gives an excellent frame of reference.
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I always find the time/token differences between the xhigh and the max effort levels for Claude models absolutely insane.
Even more so, because in a lot of their benchmarks they use the max models. I honestly think I'd rather these labs use their xhigh models as the default for benchmarking instead since I don't think the average person is even using max.