---
title: "Fable 5.1"
type: entity
entity_type: model
url: https://frontiernewswire.com/models/fable-5-1
updated: 2026-10-13T03:45:01.000Z
---

# Fable 5.1

Canonical: https://frontiernewswire.com/models/fable-5-1

- **Type:** Model
- **Signals:** 7
- **First seen:** Sep 1, 2026
- **Last seen:** Oct 12, 2026

## Recent signals

- [Anthropic says new measures like preserved thinking in Fable 5.1 and Opus 5.5 have reduced data harvesting through distillation attacks by about 90% to 99% (Anthropic)](https://frontiernewswire.com/s/anthropic-says-new-measures-like-preserved-thinking-in-fable-5-1-and-6100deca) (Oct 12, 2026)
- [Anthropic says Opus 5.5 matches Fable 5.1 "on most tasks" while costing about 40% less to run than Opus 5; Opus 5.5 costs $4/1M input and $20/1M output tokens (Matthias Bastian/The Decoder)](https://frontiernewswire.com/s/anthropic-says-opus-5-5-matches-fable-5-1-on-most-tasks-while-costing-114f6d0a) (Sep 22, 2026)
- [Artificial Analysis Coding Agent Index: GPT-6 Astra scored 67, roughly equal to Claude Opus 5, Fable 5, and Muse Spark 1.3, but trailing leader Fable 5.1's 70 (Artificial Analysis)](https://frontiernewswire.com/s/artificial-analysis-coding-agent-index-gpt-6-astra-scored-67-roughly-e07dae3d) (Sep 4, 2026)
- [Anthropic’s new Fable release is cheaper, less restrictive](https://frontiernewswire.com/s/anthropics-new-fable-release-is-cheaper-less-restrictive-va3461c8c) (Sep 1, 2026)
- [Anthropic says Fable 5.1 sets new standards on coding, knowledge work, and long-running problem-solving tasks, and can fix the root causes of software issues (Carl Franzen/VentureBeat)](https://frontiernewswire.com/s/anthropic-says-fable-5-1-sets-new-standards-on-coding-knowledge-work-9e1541a5) (Sep 1, 2026)
- [Anthropic says Fable 5.1 will cost an estimated 25% less than Fable 5 for typical workloads and up to 45% less for highly agentic work (Rachel Metz/Bloomberg)](https://frontiernewswire.com/s/anthropic-says-fable-5-1-will-cost-an-estimated-25-less-than-fable-5-de78fba8) (Sep 1, 2026)
- [Anthropic Says New Fable 5.1 AI Model Is Cheaper, Better at Coding](https://frontiernewswire.com/s/anthropic-says-new-fable-5-1-ai-model-is-cheaper-better-at-coding-v8a18bc31) (Sep 1, 2026)

## Related

- [Anthropic](https://frontiernewswire.com/companies/anthropic) (Company)
- [Claude Opus 5](https://frontiernewswire.com/models/claude-opus-5) (Model)
- [Fable 5](https://frontiernewswire.com/models/fable-5) (Model)
- [AI coding agents](https://frontiernewswire.com/topics/ai-coding-agents) (Topic)
- [Carl Franzen](https://frontiernewswire.com/people/carl-franzen) (Person)
- [Bloomberg](https://frontiernewswire.com/companies/bloomberg) (Company)
- [Artificial Analysis](https://frontiernewswire.com/companies/artificial-analysis) (Company)
- [Claude Fable](https://frontiernewswire.com/models/claude-fable) (Model)

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