What is officially true
Anthropic released Fable 5.1 on September 1, Opus 5.5 on September 22 and Sonnet 5.5 on September 28, 2026, and says Haiku 5.5 is coming “in the coming weeks.” Its newsroom has no Fable announcement after September 1.
Official source (opens in a new tab)The rumor, in order
Early September: posts on X described a new Fable pretraining run—first called “Fable 5.2,” later “Fable 5.5”—with an end-of-September or early-October window (as compiled by CellCog; we have not independently checked each of those posts). September 18: @chetaslua posted “Fable 5.2 is tested in Claude Code,” saying Fable 5.1 requests were being routed to it; the post passed 140,000 views. @notjazii reported similar routing. September 21: TestingCatalog reported stealth tests of Fable 5.2 alongside Opus 5.5—and the Opus 5.5 part came true the next day.
The @chetaslua post on X (opens in a new tab)How much to trust each source
@chetaslua sits in tier A and @notjazii in tier B of a widely shared leaker ranking; that ranking is a starting point, not our verdict. TestingCatalog’s same report got Opus 5.5 right. None of these sources has a resolved Fable call in our ledger yet. A routing test shows that something new answered a prompt; it does not prove the name, date or price.
TestingCatalog report (opens in a new tab)Will it be called 5.2 or 5.5?
Unknown. Anthropic numbered this autumn’s Opus, Sonnet and Haiku as 5.5, so “Fable 5.5” would match the family; “5.2” is simply the name that circulated first. Either way it would be the successor to Fable 5.1. This is our read, not a leak.
CellCog rumor timeline (opens in a new tab)What would count as confirmation
An Anthropic newsroom post, a model ID in the API documentation, a price on the pricing page or a system card. Screenshots, routing tests and prediction-market odds are not confirmation. We will update this page when one of those appears.
Official source (opens in a new tab)What to do while you wait
Do not buy usage credits in advance for a model that does not exist yet. Max plans and premium Team/Enterprise seats include Fable 5 and 5.1 up to 50% of weekly usage limits; Pro and Team Standard seats use them with usage credits. If you need the strongest model today, compare Fable 5.1 with Opus 5.5 on your own task.
Official source (opens in a new tab)Questions readers ask
When is Fable 5.2 coming out?
There is no official date. Leakers pointed to late September or early October 2026; late September has passed without an announcement.
Official source (opens in a new tab)Is Fable 5.5 the same as Fable 5.2?
Probably the same rumored model under two names. Anthropic has confirmed neither.
Official source (opens in a new tab)Will Fable 5.2 be free?
Unknown. Fable 5 and 5.1 were never in Claude Free; the free Fable 5 promotion ended on July 19, 2026.
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