Claude Opus 5 ignores Anthropic’s claimed May 2026 knowledge cutoff
Balance- · reddit · 2026-07-26
A user tested Claude Opus 5 against Anthropic’s documented “May 2026 reliable knowledge cutoff” and found it had no idea what happened in 2026.
According to the post:
- The model answered in detail about 2025.
- It showed no awareness of 2026 events.
- The tester shared both the Claude conversation and the docs that claim the cutoff.
The post raises a simple but notable question: how should people interpret a published cutoff date when the model does not appear to know beyond 2025?
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