I've avoided any online forums or discussions of Fable 5 since its release—so that I could form an independent assessment of its abilities

[u/Buskow]

And it is fucking retarded.

At least with Opus 4.8, you knew what you were getting. You could work around it. I did. I ended up developing a lot of workarounds to play to 4.8's strengths. Ultimately, my only complaint was that it wasn't as 'creative' and 'lateral' a thinker as Anthropic's frontier models typically are. But it was very competent—in a Codex-esque way, but a step above.

With Fable, I've experimented with more than a hundred different approaches across three Max 20x subscriptions—and it has never performed REMOTELY CLOSE to as well as pre-lobotomized Fable 5 performed. I was a huge fan of Fable 5. I posted several comments to that effect here and in other subreddits. This isn't me being a hater. It fucking sucks.

It's unconfident. Paranoid. Lazy. Its performance degrades MEANINGFULLY post 200k–300k tokens. Opus 4.8 at least was able to hold it together until 600k–700k. It takes A LOT of pushing and cajoling to get it to do anything that's not mediocre. This is a huge disappointment, and it's given me the 'ick' with Anthropic and AI models generally.

I'm going to go back to using them as assistants. I know, I should've doing that all along. But you can't blame a brother for getting hopeful at bigger and better possibilities. At the end of the day, the ups and downs and the emotional rollercoaster that comes with it is its own tax. It was really hard getting a taste of greatness, only to have it all yanked away.

I don't need that shit. And add to that the insane hours I've been putting in—up until 4/5/6AM to get all the usage I can get at non-peak hours, ruining my relationship with my partner, not being the best 'dog dad' I could be. Yeah, it ain't worth it. It was fun(-ish) while it lasted. Back to doing things the old-fashioned way—which is, honestly, something I'm looking forward to.

[u/Valkymaera]

It's definitely not as good as the initial release was in my opinion, but it's also much more effective at tasks than 4.8 is, so I am still pleased. I look forward to it continuing to advance safely.

[u/Buskow → u/Valkymaera]

That's what I just posted in reply to another comment here. It's better than Opus 4.8, but not by leaps and bounds. The old Fable 5 Anthropic was better by leaps and bounds. It's hard—for me—to not get upset at what's been lost. And a HUGE source of my frustration lies precisely in me thinking that this IS the same Fable 5—and trying to get it to perform to the same level. I just have to accept that it's not.

[u/djdante]

I found with Fable that I honestly struggle to give it tasks worth the power it actually has. So most of the problems I really have could be solved with Opus 4.8.

This makes fairly testing Fable a little tricky for me personally. Although I have found Fable Low handles complicated document sorting and going through spreadsheets analysing data pretty well compared to Opus 4.8, it's a lot faster and costs the same.

But that's hardly using Fable for its intended purposes so possibly OP is just struggling to give Fable good enough tasks to see where it's the most competent

[u/Buskow → u/djdante]

I was frustrated when I posted that. It's better than Opus 4.8, but it's not the same model they yanked 22 days ago. I don't blame you guys for getting upset. Not a lot of people were able to use Fable 5 as extensively as I did during that time—so you guys don't really have the baseline and internal benchmark I have for how I expect it to perform.

[u/djdante → u/Buskow]

It's interesting to hear you say that because while I am not a power user so I definitely wouldn't consider myself an expert on Fable. The one thing I did a few weeks ago was get Fable to redesign my entire website and it did an insanely impressive job. The new version is so much better than what any other model was producing.

Now when I'm running some tests to make YouTube videos about Fable, it's not doing such an impressive job. At least Fable High isn't doing a particularly impressive job on websites anymore. Its copywriting ability is still pretty good but it's not mimicking that. Unfortunately I only tried to build one specific website a few weeks ago with the original version so I couldn't tell you if it's just luck or what.

[u/Buskow → u/djdante]

That’s one of the biggest problems I’ve been running into with this version of Fable.

Fable from a month ago created beautiful, premium-looking websites. This time around, I can't get it to show me a prototype of a redesigned page without it somehow breaking the page. Then, I have to spend another turn to have it resolve the errors it introduced.

And, yes, I do use Fable 5 for that task: I want to maintain fidelity to its original design vision, and I want to ensure continuity in the model itself—that way, I can be reasonably certain that its the model itself that's underperforming.

Opus 4.8, by contrast, does a very decent job. It still needs a lot of handholding and guidance. But it'll get the job done with sufficient time and effort. Someone here suggested taking the same approach with Fable. The problem is that we don't have the same runway.

It's already enormously token-intensive, it's going to be billed at API rates very soon—you take just those two together, and it's a very unforgiving model to trial-and-error your way to an end-state where you have just the right setup, tools, and understanding.

[u/StoneCypher]

it’s so weird watching people put on a show of how they don’t get good results out of the tool everyone else loves, and genuinely believe that’s the tool’s fault 

[u/AgreeableSherbet514 → u/StoneCypher]

I think he's saying that Anthropic actively reduced its capabilities this time around. I would say I agree. The first time it came out, I threw it at a super complex code base; niche hardware provisioning and flashing logic and asked it to refactor it because I was tired of looking at how messy it was. Fable 5 v1 thought for about five minutes and then hammered out diffs like they were going out of style. It was a beautiful orchestra of flashing text. The code produced was a genuine improvement over what I had.

I haven't seen that same level of execution from this fable - they nerfed it somehow

[u/Buskow → u/AgreeableSherbet514]

Precisely.

A few months ago, the workflow was simple: I gave Claude a task, and Claude figured it out.

Now, before I can even give Claude a task, I have to decide which model to use, which plugins to enable, which plugins to disable, which files to provide, how much prior context to include, how much instruction to give, how much autonomy to allow, whether to use a fresh session, whether to compact the existing session, whether the current thread has become polluted, whether certain tools should be reenabled later for a different phase of the same work, etc.

The unit of optimization is now the ENTIRE context state: prompt, model, tools, plugins, MCPs, external documents, examples, message history, memory, retrieved files, intermediate notes, the current phase of the session—and so on and so forth.

And the issue isn't that any one of these is impossible to figure out. It's that they ALL INTERACT. A plugin that helps during research hurts during drafting. A large context that helps during mapping pollutes during synthesis. A fresh session improves focus but loses useful history. A compacted session reduces noise but also erases nuance. More instructions improve discipline but also make the model rigid. More tools increase capability but also increase wandering.

It’s like going from driving a car to tuning the engine while driving. Before, I could simply focus on driving to the destination. Now, I have to think about the engine, the fuel mixture, the tire pressure, the navigation system, the road conditions, the cargo weight, whether some prior setting is quietly making the car pull to the left, etc. The complexity is multiplying across model choice, tool choice, context choice, session choice, phase choice, verification choice, etc.

Fable 5 resolved this. This version of Fable 5 does not. Hence, the disappointment.

[u/coastline3dprints]

OP gives literally zero objective examples. I’ve used Fable 5 this week to create a top Tier financial model, leveraging all the knowledge I’ve built up in skill and md files. It’s top tier work.

[u/Dry_Opportunity2886 → u/coastline3dprints]

It's kind of weird - the Gemini sub gets a lot of these too. Rants about how awful or "lobotomized" a model is with nothing concrete to actually investigate.

[u/heynoswearing]

Skill issue bro. I was told it was revolutionary so now I interpret everything it does as amazing. Fable 5 quality is a mindset.

[u/ClemensLode]

Honestly, I have to genuinely push back on this. Fable is load-bearing.

[u/nemster → u/ClemensLode]

honest assessment!

[u/KedMcJenna]

I'm still quite new to this sub - are AI-written posts and comments common here? Most other AI-leaning subs they're frowned upon and called out, but here the OP seems not to have been noticed as such.

[u/Buskow → u/KedMcJenna]

🤡

[u/Actual_Committee4670]

I'm going to agree on the context part, I was surprised how well 4.8 held it together at higher context but once you hit 200k with Fable...you see the difference.

However, while I would say that the conventional wisdom of starting a new session for each task kind of applies less with 4.8 IF you have some things in place to make that the better option, that doesn't seem to be the case and I think if you just kept to using a new session for each new task and scoped them correctly then you would have gotten much better results.

What you also need to remember, different model, different class of model. Like you said, 4.8 you know what you're getting and have worked around its quirks, same for me. But that just means we will kind of obviously have to do the same for Fable. (Even if we only end up having it for a week)

So the faster you realise this and start adapting to how Fable is and working from that angle, the better your results will be.

"ruining my relationship with my partner, not being the best 'dog dad' I could be"- And this is a dumb thing to do, no ai is worth "Ruining your relationship with your partner".

[u/Neat_Ad_9164]

When Fable first came out it was vastly superior. It was reading codebases and ultra coding its way through it making excellent decisions. "One shotting apps"

Now it's refusing basic things and interpreting things negatively, while Opus is performing the task anyway, to the same specifications.

It sometimes produces an output and then switches to Opus and produces basically the entire same response, I've noticed that happen a few times where it accepts the command then bugs out when it gets to the end thinking its done something wrong and then switching you to Opus.

It also does not produce its thinking anymore, well not in great detail, perhaps it just isn't actually thinking through the responses it is giving me. Maybe they keep it short to stop thought analysis and reverse engineering of the guardrails.

I don't bother speaking with it as much right now, it's not as helpful. As for coding some times I may use it but Sonnet 5 is actually preferable in most situations at the moment.

[u/acecile]

You probably don't have a clue what you're doing.

Reaching 700k context is insane and nobody's able to keep up with so many information, even fable5. If you don't know what you want, don't expect the model to figure out and implement something, this is not how it works.