Claude Opus 5 vs Fable 5: Which Tier Earns the Money

Claude Opus 5 has been released with a price similar to Opus 4.8, but with improved performance, closing the gap with Fable 5. This means that Opus 5 is now a more reasonable choice for hard tasks, and developers should audit their code to handle the changes. The minimum cacheable prompt size has also been reduced to 512 tokens, which may affect small repeated calls. Migrating from Opus 4.8 requires careful consideration of the changes, including the default enabling of thinking and the potential for truncation risks.