This is the page for the "max" reasoning setting. The page for xhigh is https://artificialanalysis.ai/models/claude-opus-5-5-xhigh and the page for medium (the default setting) is https://artificialanalysis.ai/models/claude-opus-5-5-medium

I've failed twice to get "Generate an SVG of a pelican riding a bicycle" to work with max, because in both cases it ran out of the 128,000 token budget while it was still reasoning about the problem.

I'm suspicious that "max" may be virtually useless if it's that easy to have it overthink to the point that it doesn't get to a response.

Transcript for one attempt here - expand the "Reasoning trace" bit to see it: https://tools.simonwillison.net/markdown-svg-renderer?url=ht...

This is totally a thing I noticed myself about 3 months ago. Medium thinking effort is ideal for most tasks. At high and above, models tend to generate more output in the form of comments or code for the same problem with no real benefit. Its a self-feeding loop: more output becomes more input, which then becomes more output. High is the highest I go. If I need more intelligence, it's better to use a more powerful model with less thinking effort or break the problem into phases. Much better result.

"This is a classic test request..."

I know there's been discussion about whether pelicanmaxxing is happening, but this is at least evidence that Claude was explicitly exposed to this problem.

For people with any kind of budget, Opus 5.5's [Medium] actually can make sense dollar per intelligence/dollar per task wise. Heck, it puts some other models to shame. [Max]'s cost is completely unhinged.

My most exciting recent release is actually 5.6 Luna, not because it is the best on any index, but the dollar per work is insane value for money. I find myself more exciting by "value" than hypothetical ceilings because I'm just not in that budget category.

Hey! From the Artificial Analysis team. We also have a model releases page which shows all reasoning efforts (not just max), including the trade off curves https://artificialanalysis.ai/models/releases/claude-opus-5-...

I have experienced this with open weight models too. "Max" is for benchmaxxing the intelligence metric and is not meant for use in productive work. Like drawing pelicans.

I tried to replicate your test but after 8 minutes and more than 50 lines of "thinking" by dumping seemingly random loading-screen strings like "Placing the sun, clouds, seagulls, and sea backdrop" and "Positioning the tail feathers and calculating handlebar geometry" I gave up and cancelled the task.

I've asked Opus 5 Max for what I thought were easy tasks at work to be completed. It always fails after reaching a tool limit.

I asked Opus 5 High for the same task and requested it to minimize tool usage. It produced an answer in a few minutes that I was deploying to my target platform about 30 minutes later.

I'm amazed they didn't test xhigh thinking mode explicitly to ensure it didn't exceed the 128k thinking budget allocation. I guess pace of development gets away from everyone, even OpenAI.

On the Message Batches API, Opus 5.5 supports up to 300k output tokens with the output-300k-2026-03-24 beta header.

https://platform.claude.com/docs/en/models/opus-5-5/overview

How did you get the reasoning trace? Is it the actual one or the summarized one?

No surprise then that the default effort level for this model in Claude Code is Medium, even if you had Opus 5 set to High...

I am very interested in why it was able to overthink that much. In the 20-30mins of Max reasoning I've had so far, I'm not having the same issues (yet).

Pick 10 reasonably intelligent people randomly. How many of them do you think can draw a pelican on a bicycle? I bet most of them can barely even draw a bicycle.

This whole test tells me nothing.

The next person who proposes to use it should draw it themselves first.

The old analysis paralysis