Is Anthropic 'nerfing' Claude? Users increasingly report performance degradation as leaders push back

A growing number of developers and AI power users are taking to social media to accuse Anthropic of degrading the performance of Claude Opus 4.6 and Claude Code — intentionally or as an outcome of compute limits — arguing that the company’s flagship coding model feels less capable, less reliable and more wasteful with tokens than it did just weeks ago.

The complaints have spread quickly on Github, X and Reddit over the past several weeks, with several high-reach posts alleging that Claude has become worse at sustained reasoning, more likely to abandon tasks midway through, and more prone to hallucinations or contradictions.

Some users have framed the issue as “AI shrinkflation” — the idea that customers are paying the same price for a weaker product. Others have gone further, suggesting Anthropic may be throttling or otherwise tuning Claude downward during periods of heavy demand.

Those claims remain unproven, and Anthropic employees have publicly denied that the company degrades models to manage capacity. At the same time, Anthropic has acknowledged real changes to usage limits and reasoning defaults in recent weeks, which has made the broader debate more combustible.

One of the most detailed public complaints originated as a GitHub issue filed by Stella Laurenzo, Senior Director in AMD’s AI group. She wrote that Claude Code had regressed to the point that it could not be trusted for complex engineering work, backed by an analysis of thousands of session files. The complaint argued that Claude’s estimated reasoning depth fell sharply while signs of poorer performance rose, including more premature stopping and reasoning loops.

Anthropic’s public response focused on separating perceived changes from actual model degradation. Claude Code lead Boris Cherny thanked Laurenzo for the analysis but disputed its main conclusion. He stated that certain UI changes hide thinking to reduce latency but do not impact the underlying reasoning. He also noted that Opus 4.6 moved to adaptive thinking and a default 'medium effort' level to balance intelligence, latency, and cost, adding that users can manually switch to high effort if needed.

Benchmark claims also fueled the fire. BridgeMind reported that Claude Opus 4.6 fell from 83.3% accuracy to 68.3% in a retest. However, critics like researcher Paul Calcraft argued the comparison was misleading due to different sample sizes and statistical noise. While the technical distinction between product changes and model degradation is important to Anthropic, it remains a point of frustration for power users feeling the impact on their workflows.