Claude launched a new model yesterday (Fable 5.2). There are 4 to choose from. H
By Will Mctighe · November 11, 2026 · Curated by George's Blog
Claude launched a new model yesterday (Fable 5.2).
There are 4 to choose from. Here's what to use when:
A quick email, a deep research project, and an end-to-end workflow shouldn't start with the same model.
Yet most people pick whichever one is on default and hope for the best.
Here's the simple guide I use instead:
1/ When To Use
Haiku is for fast, one-off tasks, and Sonnet is for everyday tasks. Those two cover most of my day.
Opus is my go-to for most complex tasks. Fable is for the hardest tasks, the ones I hand over and want finished start-to-finish without me checking in.
2/ Doc Analysis
Haiku pulls answers out of simple docs. Sonnet handles normal docs and spreadsheets.
Opus is for heavy docs like RFPs. Fable is for tables and charts buried in PDFs, because it reads the numbers instead of guessing at them.
3/ Skip It When
Skip Haiku when the task is long and complex. Skip Sonnet when accuracy matters more than speed.
Skip Opus when the task is quick and simple. And skip Fable when Opus can already handle it, which is more often than I expected.
4/ Writing
Haiku is for short summaries and quick replies. Sonnet is for posts, emails and first drafts.
Opus is for drafts where every detail counts. Fable takes a full analysis all the way to a finished doc.
5/ Research
Haiku gives fast answers and pulls facts. Sonnet gives quick answers for daily decisions.
Opus is for data-heavy research work. Fable is for deep research with citations, when I need to trust every source before I share it.
6/ Ideation
Haiku is enough for coming up with a bunch of ideas. Sonnet is a real-time ideation chat, so I can push back and it pushes back harder.
Opus is for stress testing big ideas. Fable is for strategy and campaign ideas with several moving parts.
7/ Context Window
All 4 models hold 1M tokens of context now, including Haiku.
So the context window no longer decides which model I pick. The task does.
8/ Speed & Cost
Haiku is the fastest, Sonnet is close behind, and both are free on every plan.
Opus runs at a steady speed and starts from $20 a month on Pro. Fable is the slowest and is included on Max from $100 a month.
The model on default is rarely the right one for the job in front of you.
With 4 to choose from, picking the right one takes 5 seconds and saves you the next 20 minutes.
📌 Get a high-res version of this infographic here: https://lnkd.in/gKzZUq-b