Claude Fable Relaunch Disappoints Users with Nerfed Performance
Claude Fable, the company's most powerful model, is now available to all users, but early impressions are disappointing, as it appears to be nowhere near the original release. When the Department of Commerce announced that it was lifting the ban on Claude Fable, users were eagerly waiting for the model to show up on Claude Code.
However, to their surprise, Claude Fable shipped for everyone, including those with a $100 Max subscription, but there are multiple restrictions. According to Anthropic, while Fable 5 is included in Max, Pro, and Team plans, it is heavily capped. For example, you can use Fable for up to 50% of your weekly usage limits, which is not significant for such a powerful model.
Restrictions and Pay-to-Play System
But it'll get worse after July 7, as the model will transition entirely to a pay-to-play system via usage credits. This means that users will have to pay for every usage of the model, which can be a significant cost for heavy users.
The real issue, however, is the degraded performance of the model. On Reddit, users are reporting that the restored Fable 5 feels weaker, or is simply being routed through stricter safety systems more often than before. One user wrote in a Reddit post, "The new guardrails are kicking in on way too many tasks and falling back to Opus 4.8. This is not the model that got banned."
Issues with Claude Code and Desktop
The problem is not just limited to Claude desktop, as Claude Code is also struggling with similar issues. One user said Fable "didn't even let me search for dead code without switching to Opus," while another said it was "very very obvious" when the fallback triggers because Claude tells the user and visibly shifts to Opus.
Another developer claimed the model was unusable for some systems-level coding work, saying that C, C++, Rust, Win32 API references, memory-related work, and files mentioning words like "security," "vulnerable," "unsafe," or "hook" appeared to trigger a fallback or block.
Safety Guardrails and False Positives
Fable 5 may still be powerful when it actually handles the task, but the restored version appears to be far more sensitive to prompts, project files, and security-adjacent language. However, BleepingComputer understands that the model itself has not been nerfed. Instead, it is likely that Anthropic is being extra careful with the safety guardrails, which is negatively affecting Fable's daily use cases.
In fact, we observed that Fable is sometimes routed to Opus 4.8 even when the task does not appear to be a safety risk. Anthropic has said that its updated safeguards rely on a large "safety margin," which could explain the subpar experience some users are seeing with Fable.
Anthropic hasn't acknowledged the reports of false positives yet, but it's likely the company is aware of the problem and will address it in a future update. Test every layer before attackers do: Security teams log 54% of successful attacks and alert on just 14%. The rest move through your environment unseen.
The Picus whitepaper shows how breach and attack simulation tests your SIEM and EDR rules so threats stop slipping by detection. Get the whitepaper
Source: BleepingComputer