Fable is better than Opus which is better than Sonnet which is better than Haiku. They’re basically just sizes.

Though it gets even more confusing because they also have effort levels so it’s not really possible to call one fast and one slow since Fable on Medium will be faster than Opus on Max.

I agree it’s confusing, and now OpenAI is following Anthropic’s lead with their new naming (Sol, Terra, Luna).

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bonoboTP 4 hours ago | parent | next [-]

It's really not all that confusing. It takes 5 minutes to understand. Optimizing for absolutely no effort needed is silly. It's a thing, a topic, a skill, a domain. You have to get a little bit familiar with the terms in order to use it. Everything works like that. It's not that hard. The learning curve is very graceful. You can literally just start by asking any chatbot what the names mean. It's that easy.

A similar complaint was valid years ago when OpenAI had GPT-4o, o1, o3 (but no o2), o4-mini-high, GPT-4, and GPT-4.1 and GPT-3.5 etc.

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einsteinx2 2 hours ago | parent [-]

I am familiar with the terms, but I also can see how it can be confusing for a lot of people.

Arguably the complaint was more valid for those older GPT models you mentioned.

	▲	bonoboTP 2 hours ago \| parent [-]
		Ok, the boring way would be a subset of XXS, XS, S, M, L, XL, XXL like clothes sizes. But it loses some marketing appeal and a quirky touch of personality that companies like. Some models like ViTs use something similar but then introduce words with no unambiguous order, like Small, Medium/Base, Large but then I always forget if Huge or Giant is larger.

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paxys 3 hours ago | parent | prev [-]

But according to their benchmarks Opus 5 outscores Fable 5 on basically everything. So which one is “better”?

	▲	einsteinx2 2 hours ago \| parent \| next [-]
		Maybe more accurately I should have said “larger”. Fable has the most parameters, Haiku has the fewest. Also fwiw I’ve never found LLM benchmarks to match reality based on my own usage, not for the large frontier models or smaller open weight models so who knows if Opus is actually better than Fable (I doubt it).
	▲	tackta an hour ago \| parent \| prev [-]
		I think the problem is that Fable 5 is probably a bit outdated right now. Fable 5.1 or whatever they go with will be the stronger version vs Opus 5. From about 2 hours of Opus 5 use , I would say it is quite impressive.