Anthropic unveils Claude Fable 5.1 and Mythos 5.1: cheaper and more powerful

Neutral summary

Anthropic has released its new flagship models, Claude Fable 5.1 and Claude Mythos 5.1, which the company says are more powerful and cheaper than their predecessors. Fable 5.1 is available to everyone, while Mythos 5.1 is limited to vetted organizations. The cost for long, autonomous tasks has been cut by up to 45 percent, and the model has doubled its predecessor's score on some benchmarks. The company has also relaxed some safety restrictions to reduce false positives.

How it was framed

Outlets: 14. Countries: 8. Facts in the shared core: 7.

Publication timeline

1. 2026-09-01 18:30 · Frandroid (outlet profile)

   Claude Fable 5.1 : Anthropic mise sur la baisse des coûts plus que sur les benchmarks. Anthropic lance Claude Fable 5.1 et Claude Mythos 5.1, ses modèles les plus avancés pour le code.

2. 2026-09-01 18:49 · O Globo (outlet profile)

   Anthropic diz que nova versão do modelo de IA Fable é mais barato e melhor em programação. A Anthropic está lançando uma nova versão de seu poderoso modelo de inteligência artificial Fable, que, segundo a empresa, é mel…

3. 2026-09-01 18:54 · Habr News (outlet profile)

   Anthropic представила Claude Fable 5.1 — модель для сложных задач и долгой работы с ИИ-агентами. Anthropic представила новую версию модели Claude Fable 5.1, ориентированную на работу со сложными многоэтапными задачами.…

4. 2026-09-01 19:26 · Habr News (outlet profile)

   Anthropic представила Claude Fable 5.1 и Mythos 5.1. Anthropic обновила сразу две специализированные модели. Fable 5.1 получила заметный прирост в кодинге, агентных задачах и исследованиях. В Terminal-Bench Science моде…

5. 2026-09-01 19:39 · TechCrunch (outlet profile)

   Anthropic’s new Fable release is cheaper, less restrictive. Fable 5.1 includes changes meant to reduce token cost and false-positive restrictions from the model's safeguards.

6. 2026-09-01 20:01 · The Decoder (outlet profile)

   Anthropic's Claude Fable 5.1 promises better coding and research at up to 45 percent less. Anthropic launches Claude Fable 5.1 and Mythos 5.1, its most capable AI models yet. Fable 5.1 doubles its predecessor's score on…

7. 2026-09-01 20:19 · Habr News (outlet profile)

   Anthropic обновила Claude – вышли Fable 5.1 и Mythos 5.1. Anthropic выпустила обновление своих топовых моделей – Claude Fable 5.1 и Claude Mythos 5.1. Это одна и та же модель под капотом, различающаяся уровнем защитных…

8. 2026-09-01 20:32 · 3DNews (outlet profile)

   Anthropic представила Claude Fable 5.1 и Mythos 5.1 — флагманские ИИ стали умнее, дешевле и чуть раскованнее. Компания Anthropic представила Claude Fable 5.1 и Claude Mythos 5.1 — новые версии своих флагманских ИИ…

9. 2026-09-01 22:01 · The Verge (outlet profile)

   Anthropic launches Claude Fable 5.1 and says it’s up to 45 percent cheaper for agentic work. Anthropic says its newest AI models, Fable 5.1 and Mythos 5.1, address criticisms from customers about price, data reten…

10. 2026-09-01 22:23 · ITmedia (outlet profile)

    Anthropic、「Claude Fable 5.1」と「Claude Mythos 5.1」発表 「監視の難しさ」への懸念も開示. Anthropicは新LLM「Claude Fable 5.1」と「Claude Mythos 5.1」を発表した。科学研究やコーディング性能が大幅に向上し、一般提供のFableに対し、Mythosは厳格な審査制を採用。System Cardでは高度な推論力に伴うエクスプロイト成功率や監視困難性などの…

11. 2026-09-02 02:18 · QbitAI (outlet profile)

    Claude最强Fable 5.1发布！8项屠榜，最高降价45%，反蒸馏机制上线. 无论你此前让Claude处理什么任务，Fable 5.1都能做更多，并且把最难的部分完成得更出色

12. 2026-09-02 08:36 · Numerama (outlet profile)

    Claude Fable et Mythos 5.1 : Anthropic dévoile ses modèles les plus puissants, mais marche sur des œufs. Avec ses nouveaux modèles Fable 5.1 et Mythos 5.1, Anthropic revendique un nouveau palier de performance, mais dép…

13. 2026-09-02 08:51 · Heise (outlet profile)

    Anthropic legt bei Claude nach: Fable 5.1 übernimmt Benchmark-Führung. Fable 5.1 setzt sich in externen Benchmarks an die Spitze, während Mythos 5.1 mit gelockerten Schutzmechanismen mehr Cyberaufgaben bewältigen soll.

14. 2026-09-02 10:05 · Golem (outlet profile)

    Bis zu 45 Prozent günstiger: Anthropic senkt Kosten für Fable 5.1. Anthropic lockert bei Fable 5.1 einzelne Sicherheitsfilter und verbessert die Leistung bei agentischen Aufgaben. ( KI , Fable )

15. 2026-09-02 11:30 · South China Morning Post (outlet profile)

    Frontier AI at a cost: what Anthropic’s Fable 5.1 means for the US-China model race. Anthropic’s powerful new Claude Fable 5.1 model has widened its lead in performance benchmarks over Chinese rivals, even as budget-fri…

16. 2026-09-02 13:54 · AI Business (outlet profile)

    Anthropic Joins AI Price War With Release of Fable 5.1. The vendor reduced cache read pricing for Fable 5.1 and said the model is similar to Mythos 5.1, with different safeguards.

17. 2026-09-02 15:42 · 3DNews (outlet profile)

    Модель Claude Fable 5.1 за 44 минуты взломала шифр, над которым криптографы бились с 1653 года. Новая модель Claude Fable 5.1 от Anthropic нашла решение криптограммы XVII века шотландского писателя Томаса Уркхарта (Thom…

Factual core

• Anthropic unveiled its new AI models Claude Fable 5.1 and Mythos 5.1.
• Claude Fable 5.1 performs better on the most difficult parts of tasks.
• Anthropic reduced cache read pricing for Fable 5.1.
• Anthropic claims the new models reach a new level of performance.
• The price reduction applies to the retrieval of previously processed information, which can account for half or more of tokens in long tasks.
• Dianne Penn, Anthropic's product manager for research and labs, said the changes respond to customer feedback.
• Anthropic plans to allow corporate clients to keep data on their own cloud infrastructure when using advanced AI models.