Claude Fable 5: mid-tier results on coding tasks

Post by rikschennink » Fri, Jun 12, 2026, 2:18 PM UTC

aleph_minus_one wrote: post #191

renoir wrote: post #9

This matches my experience. Burned $2K to see how it will perform on frontend tasks and backend tasks. Frontend did a significantly better job than Opus on toy-scale wireframe projects by using gimmicks like fluid dynamics. Then when given medium to big tasks like multi-page web app where layouts and aesthetics must be decided by model itself, results by Fable and Opus scored indistinguishable score from human judges…

> Burned $2K to see how it will perform on frontend tasks and backend tasks. When I read such statements on HN, I nearly always ask myself: if the person has such an amount of money to burn, don't there exist much more fun opportunities to burn buckets of money than doing such experiments on LLMs?

Post by queuebert » Fri, Jun 12, 2026, 2:28 PM UTC

smoe wrote: post #107

queuebert wrote: post #64

Earlier quoted context omitted.

I don't understand how some of y'all use these things. I get garbage unless I give them very specific concrete tasks with as much context as possible. Anything that takes more than 30 min is usually a waste because the scope was too large.

I had good experiences doing multi-hour refactoring/housekeeping tasks that basically consisted of applying the same steps and rules n times. Worth noting, a significant chunk of those runs involved the agent waiting for the compiler, linters, type checks, and test suites, as well as updating journals. It’s not the agent sputtering out code for eight hours straight. And naturally I spend more time on manual verificat…

Post by repiret » Fri, Jun 12, 2026, 2:54 PM UTC

graphime wrote: post #192

aleph_minus_one wrote: post #191

Earlier quoted context omitted.

> Burned $2K to see how it will perform on frontend tasks and backend tasks. When I read such statements on HN, I nearly always ask myself: if the person has such an amount of money to burn, don't there exist much more fun opportunities to burn buckets of money than doing such experiments on LLMs?

> if the person has such an amount of money to burn, don't there exist much more fun opportunities to burn buckets of money than doing such experiments on LLMs? Do you think US$2,000 is a lot of money?

Post by rirze » Fri, Jun 12, 2026, 3:09 PM UTC

thempatel wrote: post #88

AaronAPU wrote: post #47

Earlier quoted context omitted.

I’ve found that agents are obsessed with adding more lines of code. Even when asking them to simplify they’ll remove 50 lines of code and then add 100 more. You have to explicitly tell them you want less lines of code. So I just do that after iterating on a task for a few steps.

I think the problem is that agents are inherently stochastic. Their idea of simplification changes from message to message because whatever objective it’s operating on internally is inherently opaque and changes. No matter how much you prompt it, eventually it’s going to not do what you want it to do. I built https://github.com/thempatel/mdlr for precisely this reason: externalize the objective and force the agent to…

Post by PeterStuer » Fri, Jun 12, 2026, 3:13 PM UTC