Models
Claude Fable 5.5 Release Date: What Is Confirmed So Far
Claude Fable 5.5 release date: Anthropic has not announced it yet. What the Azure listing, the partner-testing leak and Fable 5.1 tell us about when it may land.
Claude Fable 5.5 is the name everyone is searching for this week, and the first question is simple: is it out yet? People have seen it in a Microsoft cloud catalog, in an open-source code change, and in posts from leakers on X. Some blogs already write as if it launched.
This page sorts what is confirmed from what is not, as of October 21, 2026. We will update it the moment Anthropic makes an announcement.
What is Claude Fable 5.5?
Claude Fable 5.5 (also written "Fable 5.5" or "claude-fable-5-5") is the expected next version of Fable, Anthropic's most capable publicly available Claude model. If it ships, it would follow Claude Fable 5, which launched June 9, 2026, and Fable 5.1, which launched September 1, 2026, alongside the partner-only Mythos 5.1.
The "5.5" number fits a pattern. Anthropic already moved its other three models to 5.5: Opus 5.5 was announced September 22, Sonnet 5.5 followed about a week later, and Haiku 5.5 arrived October 7. Fable is the only tier still on 5.1. That gap is a big reason people expect a Fable 5.5. But a pattern is not an announcement.
Claude Fable 5.5 release date
There is no official date. Anthropic's newsroom shows no Fable 5.5 post as of this morning. Its latest model post is "Introducing Claude Haiku 5.5" on October 7.
Here is the timeline of every real clue so far:
| Date (2026) | What happened | How solid |
|---|---|---|
| June 9 | Claude Fable 5 launches | Official |
| September 1 | Fable 5.1 and Mythos 5.1 launch | Official |
| Sept 22 to Oct 7 | Opus, Sonnet and Haiku all move to 5.5 | Official |
| October 13 | Azure's model API in the East US 2 region returns "claude-fable-5-5", marked generally available, with a retirement date of December 5, 2027. LiteLLM, an open-source tool, adds it the same day | Real record, not an announcement |
| October 14 | A LiteLLM contributor proposes removing the entry, saying no deployment existed. That proposal was closed | Disputed |
| October 15 | X leaker Lyra (@lyraxana) says partner companies have Fable 5.5 for testing and expects a launch "next week" | Rumor |
| October 21 | Still no word from Anthropic or Microsoft | Official silence |
One more data point: Fable 5.1 shipped 84 days after Fable 5. As of today, it has been 50 days since Fable 5.1. If Anthropic kept the same rhythm, late November would fit. If the leak is right, it could be much sooner. Nobody outside Anthropic knows. There are even prediction markets betting on the date, which tells you how uncertain it is.
Claude Fable 5.5 price and specs (rumored)
You may see numbers like "$10 per million input tokens, $50 per million output tokens, 1 million token context, 128K output." Be careful. The LiteLLM change itself says those values were inherited from the Fable 5.1 entry, and that no source had stated a price, context window or capability for 5.5. In other words, those are Fable 5.1's numbers pasted onto a new name.
| Claude Fable 5.1 (confirmed) | Claude Fable 5.5 (not confirmed) | |
|---|---|---|
| Status | Released September 1, 2026 | Not announced |
| API name | claude-fable-5-1 | claude-fable-5-5 (seen on Azure) |
| API price per 1M tokens | $10 input, $50 output | Unknown (copied 5.1 figures circulating) |
| Cache reads per 1M tokens | $0.25 | Unknown |
| Benchmarks | Anthropic reported records on Terminal-Bench 4.0 and Humanity's Last Exam | None published |
Fable 5.1's own launch was mostly about cost. Anthropic kept the list price but cut cache reads to $0.25 per million tokens, and said typical workloads would cost about 25% less, up to about 45% less for heavy agent work. It also reduced false alarms from its safety filters. If Fable 5.5 follows Opus 5.5 and Sonnet 5.5, expect the pitch to be about smarter reasoning and agent work, but that is our guess, not a fact.
Is Claude Fable 5.5 free?
It cannot be free yet because it is not out, and Anthropic has said nothing about which Claude plans will get it. Treat any site that offers "free Fable 5.5 access" today with suspicion, since there is no public model for it to serve.
Claude Fable 5.5 vs Opus 5.5 and GPT-6 Astra
Fable sits above Opus in Anthropic's lineup. Today the comparison people actually search is "Fable 5.1 vs Opus 5.5": the newer Opus versus the older but higher-tier Fable. A Fable 5.5 would end that awkward overlap. On the OpenAI side, the rival to beat is GPT-6 Astra. Meta's model card says its new Muse Wonder performs about as well as Fable 5.1 and GPT-6 Astra, so the bar Fable 5.5 has to clear is already high.
What this means for you
If you write code against the Claude API, wait for Anthropic's model page before you change anything. A catalog entry is not a model you can call, and copied prices are not a bill you can plan around.
If you just want AI to help with real tasks, the lesson is the same one this year keeps teaching: model names change every few weeks. In October alone we covered Gemini 4 Argon, a new DeepSeek model and two Meta releases. Waiting for the "right" model means waiting forever.
That is why we built Agentic AI around agents instead of model names. You pick a job, a team of expert agents plans it and does the work on your iPhone, and you never have to track which version came out this week.
Quick answers
Is Claude Fable 5.5 out? No. As of October 21, 2026, Anthropic has not announced Claude Fable 5.5. The latest Fable model is Fable 5.1, released September 1, 2026.
What is the Claude Fable 5.5 release date? There is no official date. A leaker said on October 15 that a launch was expected the following week, which has not been confirmed. Fable 5.1 came 84 days after Fable 5.
Was Fable 5.5 really on Azure? Azure's model API in one region returned a "claude-fable-5-5" entry starting October 13, which the open-source LiteLLM project recorded. Microsoft has not commented, and the public Foundry catalog did not show a usable model.
How much will Claude Fable 5.5 cost? Unknown. The $10 and $50 per million token figures going around are Fable 5.1's prices copied onto the new name.
Will Claude Fable 5.5 be in Claude Code? Nothing is confirmed. Anthropic has not said which apps or plans will get Fable 5.5, because it has not announced the model at all. Check our glossary for the terms in this story.
Sources: Anthropic newsroom · LiteLLM PR #46201 · 36Kr · TechCity Authority · OrcaRouter · AI Business: Fable 5.1 · Business Today: Fable 5.1
