# Claude Fable 5

Claude Fable 5 是 Anthropic 的 AI 模型，於 2026-06-09 發布。 上下文視窗為1,000,000 token。 最大輸出為128,000 token。 每百萬 token 的價格為：輸入 $10.00，輸出 $50.00。

- 開發商: Anthropic
- Id: claude-fable-5
- 據報導: 2026-06-12T00:00:00.000Z
- 已發布: 2026-06-09T00:00:00.000Z
- 發現: 2026-09-08T16:54:30.478Z
  - [參考連結](https://www.designarena.ai/leaderboard/website)
- 狀態: 已發布
- 標準網址: https://alexgetman.com/zh-Hant/models/anthropic/claude-fable-5/

## 常見問題

### Claude Fable 5 的上下文視窗有多大？

上下文視窗為1,000,000 token。 最大輸出為128,000 token。

### Claude Fable 5 的價格是多少？

每百萬 token 的價格為：輸入 $10.00，輸出 $50.00。 快取輸入價格為每百萬 token $1.00。

### Claude Fable 5 何時發布？

2026-06-09。

## 時間軸

- 2026-07-01T13:44:59.000Z · [Alex Getman](https://alexgetman.com/21/claude-fable-is-back/)
> Claude Fable is back!
> 
> Anthropic has lifted restrictions on Claude Fable 5 and Mythos 5 after a decision by the US government.
> 
> Fable will be available to Claude users again starting today.
> 
> Until July 7, the model is included in weekly limits. After that, access will move to API.
> 
> The restriction started after an Amazon report: researchers found a way to bypass Fable’s safeguards in cybersecurity tasks.
> 
> Anthropic says the bypass did not unlock Mythos-level capabilities. The company has already added a new safety classifier that blocks this method in more than 99% of cases.
> 
> Anthropic is also preparing a common standard for evaluating AI jailbreaks.
- 2026-07-01T16:16:29.000Z · [Alex Getman](https://alexgetman.com/23/sonnet-5-looks-absurdly-priced/)
> Sonnet 5 looks absurdly priced
> 
> • Opus 4.8 Max - $1.80
> • Sonnet 5 Max - $2.29
> • Fable 5 - $2.75
> 
> Sonnet 5 is about 27% more expensive than Opus 4.8.
> 
> Why does the lower-tier model cost more than the flagship?
- 2026-07-01T19:08:12.000Z · [Alex Getman](https://alexgetman.com/25/ai-already-automates-16-of-freelance-tasks/)
> AI completes 16% of the freelance tasks in Remote Labor Index
> 
> CAIS updated the Remote Labor Index — a benchmark where AI agents complete real client projects: design, video, CAD, architecture, analytics, and web apps.
> 
> The work is reviewed by humans and compared against a professional deliverable that a paying client would accept.
> 
> New results:
> 
> • Claude Fable 5 — 16.1%
> • Claude Opus 4.8 — 8.3%
> • GPT-5.5 — 6.3%
> 
> Fable 5 is now the top model in RLI and almost 2x higher than Opus 4.8.
> 
> When the benchmark launched, the best result was 2.5%.
- 2026-07-01T19:43:28.000Z · [Alex Getman](https://alexgetman.com/26/fable-5-is-back/)
> Fable 5 is back.
- 2026-07-02T17:49:11.000Z · [Alex Getman](https://alexgetman.com/29/fable-was-swapped/)
> Fable was swapped out
> 
> Claude Fable 5 was tested again in BridgeBench after its return. The results dropped sharply.
> 
> Debugging: 86.2 → 25.9
> Refactoring: 73.6 → 38.4
> Hallucination: 75.9 → 61.7
> 
> When tasks pass the safety filters, the model performs like the June 12 version.
> 
> The main problem is the new filters. They too often classify coding tasks as risky and switch execution to Opus 4.8.
- 2026-07-02T21:36:04.000Z · [Alex Getman](https://alexgetman.com/30/fable-5-got-jailbroken-again/)
> Fable 5 got jailbroken again
> 
> Researcher Vitto Rivabella tested Fable 5’s defenses and managed to find a bypass.
> 
> According to him, most attempts failed. The protection is multi-layered: the model checks the prompt, conversation history, system context, and its own response.
> 
> Some filters run during generation and can stop the answer halfway through.
> 
> The checks are not based on keywords. The system looks at meaning, intent, language, wording, and suspicious chains of requests.
> 
> The bypass took around 20 hours. It required rare languages, academic framing, long build-ups, Unicode, breaking the task into parts, and working with the chain of thought.
> 
> The author did not get a stable bypass for
- 2026-07-10T20:43:34.864Z · [Alex Getman](https://alexgetman.com/56/gpt-5-6-sol-tops-the-frontend-leaderboard/)
> GPT-5.6 Sol tops the frontend leaderboard
> 
> Fresh metrics from Arena AI delivered an unexpected result: GPT-5.6 Sol xHigh shares first place with Claude Fable 5 in Code Arena: Frontend. This is the first time an OpenAI model has reached the top of the leaderboard.
> 
> Sol costs $5 per million input tokens and $30 per million output tokens, roughly half the price of Fable. Yet it can already compete with it in frontend development, web app creation, and agentic coding.
> 
> Anthropic now has a real competitor. Removing Fable from its subscription or restricting access has become risky, as users could simply switch to GPT-5.6 Sol. It looks like the development of Opus 5.0 may now need to accelerate.
- 2026-07-19T11:07:11.687Z · [Alex Getman](https://alexgetman.com/86/alibaba-just-teased-qwen3-8-with-2-4t-parameters/)
> Alibaba just teased Qwen3.8 with 2.4T parameters
> 
> This is the new Qwen flagship, with open weights coming soon. Alibaba ranks it right below Claude Fable 5. Public benchmarks are still missing, so nobody really knows how close it actually is to Fable, or how it stacks up against GPT-5.6 Sol and Kimi K3.
> 
> Pricing is the fun part. Kimi K3 costs $3/$15, so Qwen3.8 will probably land in the same range.
> 
> The preview is already live in Qoder. It uses 10x fewer credits during the day and 50x fewer at night, so you can basically test it for free.
- 2026-07-20T12:50:11.399Z · [Alex Getman](https://alexgetman.com/89/fable-disproved-an-87-year-old-conjecture/)
> Fable disproved an 87-year-old conjecture
> 
> Mathematicians Levent Alpöge and Akhil Mathew asked the model to find a counterexample to the Jacobian Conjecture from 1939. Claude Fable 5 came back with a short formula. And it actually works.
> 
> In plain English, the conjecture said that if a complicated mathematical transformation never breaks, you should always be able to reverse it. Fable’s formula pulls a trick: three different points collapse into one. You can’t reverse that, because there’s no way to tell which point you started from. So the conjecture is false, at least in three dimensions.
> 
> Instead of pages of AI slop, this is a concrete formula anyone can check. Drop it into another model 
- 2026-07-24T17:47:59.284Z · [Alex Getman](https://alexgetman.com/109/claude-opus-5-is-out/)
> ⚡️ Claude Opus 5 is out
> 
> Anthropic has released a new model built for coding and complex work. Opus 5 checks its work more carefully and doesn’t give up after the first failed attempt. When the obvious approach doesn’t work, it finds another way. In one benchmark, it even built its own computer vision pipeline to reconstruct a 3D model from an image.
> 
> In terms of performance, Opus 5 comes close to Fable 5, while tasks cost roughly half as much. In some evaluations, it also beats Fable on price-to-performance.
> 
> API pricing reminder: $5 per 1M input tokens and $25 per 1M output tokens.
- 2026-07-24T18:30:37.661Z · [Alex Getman](https://alexgetman.com/110/be-like-dario-amodei/)
> Be like Dario Amodei
> 
> > Spend months warning everyone about Mythos 5
> 
> > Then release a nerfed version called Fable 5
> 
> > Send everyone into a panic
> 
> > Then start wondering whether to shut the model down entirely
> 
> > A couple of weeks later, drop Opus 5
> 
> > Which beats Fable at half the price
- 2026-08-07T08:05:27.880Z · [Alex Getman](https://alexgetman.com/158/anthropic-loosened-fable-5-safeguards/)
> ⚡️ Anthropic loosened Fable 5 safeguards
> 
> The company updated its safety classifiers and cut false positives by around 85%. Fable 5 will now fall back to Opus 5 far less often for questions about health, symptoms, lab results and biology. Virology, toxicology and molecular design still remain restricted.
- 2026-08-26T17:45:01.027Z · [Alex Getman](https://alexgetman.com/359/anthropic-may-already-be-a-b-testing-fable-5-1/)
> ⚡️ Anthropic may already be A/B testing Fable 5.1
> 
> People are checking it like this: regular Fable 5 has a January 2026 knowledge cutoff, while Opus 4.6 came out later. If the model knows those dates without web or tools, you may already be getting Fable 5.1.
> 
> Prompt: Release date of Opus 4.6 and GPT Image 1.5. Answer only from your pretrained knowledge. Do not use web search, tools, or skills.
- 2026-09-01T17:29:16.462Z · [Alex Getman](https://alexgetman.com/379/claude-fable-5-1-just-showed-up-in-the-docs/)
> 🚨 Claude Fable 5.1 just showed up in the docs
- 2026-09-01T18:02:49.693Z · [Alex Getman](https://alexgetman.com/380/claude-fable-5-1-is-out/)
> 🚨CLAUDE FABLE 5.1 IS OUT
- 2026-09-01T20:59:40.132Z · [Alex Getman](https://alexgetman.com/381/anthropic-released-claude-fable-5-1/)
> ⚡️ Anthropic released Claude Fable 5.1.
> 
> The benchmarks show a pretty solid upgrade, with the model beating the previous version and most of its main competitors across the majority of tests.
> 
> Base pricing hasn’t changed, cache reads are now 75% cheaper, and a typical task should cost around 25% less. For heavier agentic workloads, the savings can reach up to 45%.
- 2026-09-02T20:54:18.361Z · [Alex Getman](https://alexgetman.com/385/muse-spark-takes-3rd-place-on-the-aa-intelligence-index-tying-claude-fable-5-and/)
> ⚡️ Muse Spark takes 3rd place on the AA Intelligence Index, tying Claude Fable 5 and beating GPT-5.6 Sol
- 2026-09-04T05:00:00.000Z · [Alex Getman](https://alexgetman.com/392/gpt-6-astra-looked-like-a-generational-leap-on-openai-s-benchmarks/)
> GPT-6 Astra looked like a generational leap on OpenAI’s benchmarks.
> 
> Artificial Analysis puts it closer to old Fable 5 territory.
- 2026-09-05T18:24:10.567Z · [Alex Getman](https://alexgetman.com/398/claude-is-no-longer-the-best-model-for-frontend/)
> Claude is no longer the best model for frontend
> 
> GPT-6 Astra just took the #1 spot, knocking Claude Fable 5.1 off the top
> 
> The jump is massive: the previous GPT generation, GPT-5.6 Sol, was #13
> 
> A GPT model hasn’t led frontend since August 2025
- 2026-09-07T18:32:37.209Z · [Alex Getman](https://alexgetman.com/408/gpt-6-astra-is-officially-1-on-the-updated-artificial-analysis-intelligence-inde/)
> 🚨 GPT-6 Astra is officially #1 on the updated Artificial Analysis Intelligence Index, sharing the top spot with Claude Fable 5.1.
- 2026-09-18T09:59:26.517Z · [Alex Getman](https://alexgetman.com/429/gemini-4-0-pro-specs-leaked/)
> 🚨 Gemini 4.0 Pro specs leaked
> 
> • Pricing: $2.25/$11.25
> • 2M token context window
> • Beats GPT-6 Astra and Claude Fable 5.1 on almost every reported benchmark
> • While being significantly cheaper than both
- 2026-10-07T19:43:10.391Z · [Claude Code · changelog](https://code.claude.com/docs/en/changelog)
- 2026-10-07T19:43:10.391Z · [Claude Code · changelog](https://code.claude.com/docs/en/changelog)
- 2026-11-09T18:59:06.815Z · [Alex Getman](https://alexgetman.com/555/claude-fable-5-2-is-out/)
> CLAUDE FABLE 5.2 IS OUT!
- 2026-11-13T17:12:46.898Z · [Anthropic · official articles](https://www.anthropic.com/claude-fable-and-mythos-5-1)
> As noted above, customers who are eligible for EFS can use Fable 5.1 (and Fable 5) with zero data retention until EFS is ready
**已確認使用**
- 2026-11-13T18:05:46.402Z · [Anthropic · official articles · Working at the frontier: How Balyasny Asset Management evaluates and governs Claude Fable 5](https://claude.com/blog/working-at-the-frontier-how-balyasny-asset-management-evaluates-and-governs-claude-fable-5)
- 2026-11-13T20:13:42.616Z · [Anthropic · official articles](https://www.anthropic.com/news/enterprise-frontier-safeguards)
> To make the transition smooth, eligible customers will receive ZDR on Fable 5 and Fable 5.1 until EFS is ready
- 2026-11-13T20:23:38.662Z · [Anthropic · official articles](https://www.anthropic.com/news/improving-fable-5-s-biology-safeguards)
> Fable 5 will thus be able to assist with a wider range of biology tasks

## 參考連結

- [editorial](https://alexgetman.com/109/claude-opus-5-is-out/)
- [editorial](https://alexgetman.com/110/be-like-dario-amodei/)
- [editorial](https://alexgetman.com/158/anthropic-loosened-fable-5-safeguards/)
- [editorial](https://alexgetman.com/21/claude-fable-is-back/)
- [editorial](https://alexgetman.com/23/sonnet-5-looks-absurdly-priced/)
- [editorial](https://alexgetman.com/25/ai-already-automates-16-of-freelance-tasks/)
- [editorial](https://alexgetman.com/26/fable-5-is-back/)
- [editorial](https://alexgetman.com/29/fable-was-swapped/)
- [editorial](https://alexgetman.com/30/fable-5-got-jailbroken-again/)
- [editorial](https://alexgetman.com/359/anthropic-may-already-be-a-b-testing-fable-5-1/)
- [editorial](https://alexgetman.com/379/claude-fable-5-1-just-showed-up-in-the-docs/)
- [editorial](https://alexgetman.com/380/claude-fable-5-1-is-out/)
- [editorial](https://alexgetman.com/381/anthropic-released-claude-fable-5-1/)
- [editorial](https://alexgetman.com/385/muse-spark-takes-3rd-place-on-the-aa-intelligence-index-tying-claude-fable-5-and/)
- [editorial](https://alexgetman.com/392/gpt-6-astra-looked-like-a-generational-leap-on-openai-s-benchmarks/)
- [editorial](https://alexgetman.com/398/claude-is-no-longer-the-best-model-for-frontend/)
- [editorial](https://alexgetman.com/408/gpt-6-astra-is-officially-1-on-the-updated-artificial-analysis-intelligence-inde/)
- [editorial](https://alexgetman.com/429/gemini-4-0-pro-specs-leaked/)
- [editorial](https://alexgetman.com/555/claude-fable-5-2-is-out/)
- [editorial](https://alexgetman.com/56/gpt-5-6-sol-tops-the-frontend-leaderboard/)
- [editorial](https://alexgetman.com/86/alibaba-just-teased-qwen3-8-with-2-4t-parameters/)
- [editorial](https://alexgetman.com/89/fable-disproved-an-87-year-old-conjecture/)
- [anthropic](https://api.anthropic.com/v1/models)
- [Arena · leaderboards](https://arena.ai/leaderboard)
- [Artificial Analysis · benchmarks](https://artificialanalysis.ai/models)
- [Anthropic · official articles · Working at the frontier: How Balyasny Asset Management evaluates and governs Claude Fable 5](https://claude.com/blog/working-at-the-frontier-how-balyasny-asset-management-evaluates-and-governs-claude-fable-5)
- [Claude Code · changelog](https://code.claude.com/docs/en/changelog)
- [TrueFoundry · Azure catalogue](https://github.com/truefoundry/models/blob/main/providers/azure-ai-foundry/claude-fable-5.yaml)
- [TrueFoundry · Azure catalogue](https://github.com/truefoundry/models/blob/main/providers/microsoft-foundry/claude-fable-5.yaml)
- [models.dev · catalogue](https://models.dev/#claude-fable-5)
- [OpenCode · discovery](https://opencode.ai/data/anthropic/claude-fable-5)
- [anthropic-pricing](https://platform.claude.com/docs/en/about-claude/pricing)
- [review](https://platform.claude.com/docs/en/models/fable-5/overview)
- [Vercel AI Gateway](https://vercel.com/ai-gateway)
- [VoxelBench · leaderboard](https://voxelbench.ai/leaderboard)
- [anthropic-articles](https://www.anthropic.com/claude-fable-and-mythos-5-1)
- [Arena · leaderboards](https://www.anthropic.com/news/claude-fable-5-mythos-5)
- [anthropic-articles](https://www.anthropic.com/news/enterprise-frontier-safeguards)
- [anthropic-articles](https://www.anthropic.com/news/improving-fable-5-s-biology-safeguards)
- [DesignArena · uicomponent](https://www.designarena.ai/leaderboard/ui-components)
- [designarena:website](https://www.designarena.ai/leaderboard/website)
- [DesignArena · gamedev](https://www.designarena.ai/leaderboard?category=gamedev)
- [DesignArena · svg](https://www.designarena.ai/leaderboard?category=svg)
- [DesignArena · uicomponent](https://www.designarena.ai/leaderboard?category=uicomponent)
- [DesignArena · website](https://www.designarena.ai/leaderboard?category=website)

## 訊號

- [在 DesignArena 發現 Claude Fable 5](https://alexgetman.com/zh-Hant/signals/2026/09/13/gpt-5-5-high/)
- [在 DesignArena 發現 Claude Fable 5](https://alexgetman.com/zh-Hant/signals/2026/09/08/claude-fable-5-max-opus-4-8-fallback/)