By 2026, your hallucination rate depends entirely on the benchmark. We found...

https://fair-wiki.win/index.php/Even_with_Web_Search,_Claude-Opus-4.5_Hallucinated_30.2%25:_Should_You_Worry%3F

By 2026, your hallucination rate depends entirely on the benchmark. We found that even with live web search, HalluHard still hits a 30.2% error rate. Stop trusting single-score metrics for your agents. Here is how to measure reliability before you ship.