ANTHROPIC · MODEL RELEASE TRACKER

Claude Fable 5

Claude Fable 5 is a specific, generally available model in Anthropic’s Fable line. Anthropic materials describe Fable 5 as representing “frontier” levels of capability versus other models (e.g., Opus 5). Fable models are subject to stricter, generally-available safeguards that block some life-sciences tasks; Fable 5 has also been used in coding-agent tests.

UPDATED 2026-09-25

CURRENT SNAPSHOT2/5 DIMENSIONS WITH DATA

The dimensions that change the decision.

PRICING

Not established from the available sources.

CONTEXT WINDOW

Not established from the available sources.

MODALITIES

Not established from the available sources.

BENCHMARKS

CursorBench 3.2 performance comparisonAnthropic reports that on CursorBench 3.2 at max effort, Opus 5 performs within 0.5% of Claude Fable 5's peak score, indicating Fable 5's peak is marginally higher on that benchmark.2026-09-16

AVAILABILITY

Used in coding‑agent testsAn AWS blog describing agent-based SageMaker deployments cites tests that used "Auto or Claude Fable 5" with a coding agent, indicating Fable 5 was used in coding-agent deployment experiments.2026-09-18

RELEASE TIMELINE

Published, source-backed release events only.

2026-09-16

6 SOURCES · IMPORTANCE 8.0

Anthropic releases Claude Opus 5 — lower-cost model claiming near‑frontier performance

Anthropic announced Claude Opus 5, a new model positioned as a cost‑efficient successor to Opus 4.8 and the new default on Claude Max (and the strongest on Claude Pro). Anthropic says Opus 5 matches or exceeds prior models on many coding, knowledge‑work and scientific benchmarks (Frontier‑Bench, GDPval‑AA, CursorBench, ARC‑AGI, Zapier AutomationBench, OSWorld) at lower cost per task while remaining behind Mythos 5 on security and biology frontier tasks; the company also reports improved alignment and safety in pre‑deployment audits and links a System Card for more details.

→

VERIFIABLE FACTS

Every value stays attached to a source and date.

CAPABILITIES · Described as 'frontier' level capabilityDEVELOPER CLAIM

Anthropic’s Opus 5 announcement characterizes Opus 5 as coming close to the "frontier intelligence" of Claude Fable 5, implying Fable 5 represents a frontier-level capability.

BENCHMARKS · CursorBench 3.2 performance comparisonDEVELOPER CLAIM

Anthropic reports that on CursorBench 3.2 at max effort, Opus 5 performs within 0.5% of Claude Fable 5's peak score, indicating Fable 5's peak is marginally higher on that benchmark.

SAFETY · Subject to stricter safeguards that block some life‑science tasksDEVELOPER CLAIM

Anthropic describes its "generally available Fable models" as blocking a range of life-sciences tasks (examples given include drug discovery, research biology, clinical development, and manufacturing), and contrasts these safeguards with the Life Sciences Verification Program grants that allow broader access to other models.

AVAILABILITY · Used in coding‑agent testsDEVELOPER CLAIM

An AWS blog describing agent-based SageMaker deployments cites tests that used "Auto or Claude Fable 5" with a coding agent, indicating Fable 5 was used in coding-agent deployment experiments.

WHAT CHANGED

Stored passport versions, without reconstructed history.

2026-09-25Passport created4 facts

Anthropic releases Claude Opus 5 — lower-cost model claiming near‑frontier performance

Anthropic’s Opus 5 announcement characterizes Opus 5 as coming close to the "frontier intelligence" of Claude Fable 5, implying Fable 5 represents a frontier-level capability.

Anthropic reports that on CursorBench 3.2 at max effort, Opus 5 performs within 0.5% of Claude Fable 5's peak score, indicating Fable 5's peak is marginally higher on that benchmark.

An AWS blog describing agent-based SageMaker deployments cites tests that used "Auto or Claude Fable 5" with a coding agent, indicating Fable 5 was used in coding-agent deployment experiments.

Optional analytics