No, not Fable 5.
No, not Mythos 5.
Apparently, there are a lot of new Claude models.
They’ve also released Sonnet 5. And it’s “the most agentic Sonnet model yet”. Isn’t that assumed at this point?
This new Sonnet model can basically operate at a level that required Opus a few months ago. What that means practically is that if you have workflows that are running on a slightly older Opus model (4.7 or earlier), you might be able to transition to Sonnet 5, get the same performance and have massive cost savings over time. In theory at least.
Sonnet 5 is “a substantial improvement over its predecessor, Sonnet 4.6” on -
(unlike other recent models…) Sonnet 5 is available across all plans. It is the default model on free and pro.
Through Aug 31, 2026, Sonnet 5 is priced at $2/million input tokens and $10/million output tokens. The prices go up to $3 and $15 respectively after that date.
There’s obviously much more that could be said about the new model but, if you are interested, go to claude and start using it…