RankingClaude Fable 5.1

Claude Fable 5.1

Data updated 22 Oct 2026

66 published benchmark measures · 16 benchmark families contribute across 5 task areas. 4 capability estimates available in the full profile. See all results ↓ · Compare published benchmarks →

Model evidence summary

This profile combines published settings. It is not a runnable configuration or a leaderboard rank. Compare measured configurations →

Performance profile

Capabilities

Adjusted comparison score · 0–100

Filled points are supported; hollow points are preliminary. Lines stop at unknown capabilities. Exact values and sources follow below.

Agentic5 families · 0 with independent evidence · Supported97.1

5 core families; 4 direct opponents across 2 labs.

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: 96.3–98.0; 0/13 scenarios unsupported. Without one publisher: 94.0–97.8; 0/15 unsupported. Smoothing check: 90.7–98.9; 0/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: family and publisher holdouts improved on neutral predictions within evaluated coverage; source sensitivity still requires inspection. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

AutomationBench: 87.5 observed win share
Anthropic, OpenAI · Source 1 Source 2
GDPval: 100.0 observed win share
Anthropic · Source 1
OSWorld: 100.0 observed win share
Anthropic · Source 1 Source 2
OfficeQA: 100.0 observed win share
Anthropic · Source 1 Source 2
Terminal-Bench Science: 75.0 observed win share
OpenAI · Source 1

Hard reasoning4 families · 2 with independent evidence · Supported81.4

4 core families; 61 direct opponents across 10 labs.

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: 75.6–85.1; 0/6 scenarios unsupported. Without one publisher: 71.9–82.7; 0/16 unsupported. Smoothing check: 74.4–84.3; 0/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: family and publisher holdouts improved on neutral predictions within evaluated coverage. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

GPQA: 40.0 observed win share
OpenAI, artificialanalysis.ai · Source 1 Source 2
ARC-AGI: 52.2 observed win share
Anthropic, OpenAI, arcprize.org · Source 1 Source 2 Source 3 Source 4 Source 5
Humanity’s Last Exam: 100.0 observed win share
Anthropic, OpenAI · Source 1 Source 2 Source 3
FrontierMath: 50.0 observed win share
OpenAI · Source 1

Coding4 families · 1 with independent evidence · Supported93.9

4 core families; 21 direct opponents across 7 labs.

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: 90.8–96.6; 0/6 scenarios unsupported. Without one publisher: 92.6–94.9; 0/19 unsupported. Smoothing check: 86.0–97.0; 0/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: family and publisher holdouts improved on neutral predictions within evaluated coverage. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

Terminal-Bench: 88.6 observed win share
Anthropic, OpenAI, tbench.ai · Source 1 Source 2 Source 3
SWE-bench Multilingual: 50.0 observed win share
Anthropic · Source 1
SWE-bench Pro: 100.0 observed win share
Anthropic · Source 1
DeepSWE: 0.0 observed win share
OpenAI · Source 1

Human prefNo comparable evidenceUnknown

0 core families; 0 direct opponents across 0 labs. No admitted core comparisons

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: No supported estimate; 1/1 scenarios unsupported. Without one publisher: No supported estimate; 1/1 unsupported. Smoothing check: No supported estimate; 3/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: cross-family and cross-publisher predictions could not be evaluated from the available comparison network. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

Knowledge2 families · 0 with independent evidence · PreliminaryUnknown

2 core families; 2 direct opponents across 1 labs. No connected comparison to the complete reference panel

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: No supported estimate; 4/4 scenarios unsupported. Without one publisher: No supported estimate; 5/5 unsupported. Smoothing check: No supported estimate; 3/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: almost no publisher-held-out comparisons remained estimable. Cross-source validity is unresolved. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

Gmmlu: 100.0 observed win share
Anthropic · Source 1
Milu: 100.0 observed win share
Anthropic · Source 1

Multimodal1 families · 0 with independent evidence · Preliminary95.1

1 core families; 2 direct opponents across 1 labs. Needs broader benchmark and opponent support

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: No supported estimate; 8/8 scenarios unsupported. Without one publisher: No supported estimate; 8/8 unsupported. Smoothing check: No supported estimate; 3/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: limited publisher-held-out coverage. Cross-source validity is unresolved. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

Chartography: 100.0 observed win share
Anthropic · Source 1 Source 2

Long contextNo comparable evidenceUnknown

0 core families; 0 direct opponents across 0 labs. No admitted core comparisons

Estimated against the same complete panel: gpt-5.6-sol claude-opus-4-8 gemini-3.1-pro . Indirect comparisons assume performance can be summarized by one strength within this capability.

Refit without one family: No supported estimate; 5/5 scenarios unsupported. Without one publisher: No supported estimate; 5/5 unsupported. Smoothing check: No supported estimate; 3/3 unsupported. These are sensitivity checks, not confidence intervals.

Audit: family and publisher holdouts underperformed neutral predictions. Treat this as an exploratory estimate. Validation audit.

Matched family win shares below describe source evidence; they are not averaged to produce the adjusted score.

Scores estimate outcomes against a shared reference panel; they are not accuracy percentages. Sparse or disconnected evidence cannot qualify an overall profile. Open a capability to inspect its evidence.

Reported effort · Mixed settings

Settings reported in this model's published benchmark results, including results outside the aggregate. Effort names are provider-specific. These are not API defaults or equal compute budgets.

Auto thinking: 2 observations
High: 1 observations
Max: 34 observations
Medium: 3 observations
XHigh: 4 observations
Not specified: 65 observations

Mixed settings means multiple settings occur in the evidence. Best across efforts means the source selected its best reported result across settings; it does not mean Max. Unspecified settings stay unknown. This model-summary chart combines reported settings. The leaderboard keeps identified configurations separate and excludes unknown effort.

Inspect each result and its source ↓ · Download effort evidence

Score contributions and missing evidence

16 contributing families across 5 capabilities. Fixed reference panels do not change when the catalog expands.

Capability is fitted jointly across families. Capability estimates below describe different task areas; their weighted sum is not the Capability score.

Results without reviewed compatibility or a reference match remain in the raw evidence below. Coverage counts only contributing results.

Model information & shareable badge

Lab: Anthropic
Catalog status: active
Availability: Public provider catalog; account and region restrictions may apply
Family: Claude Fable
Released: —
Context: 1,000,000 tokens
License: proprietary
Model card: https://platform.claude.com/docs/en/about-claude/model-deprecations
Default Capability family coverage: /badge/claude-fable-5-1.svg

Benchmark scores & sources

Original results, evaluation harnesses, and evidence behind this model.

Benchmark	Bucket	Score	Harness	Evidence	Source-recorded date
Terminal-Bench-Science · 0.1	Coding	52.6% Reported settings & source 70tasks; Claude Code --bare max; Fable10trials/task, Opus12; GPT Codex CLI max from public board. Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures. Claude Fable 5.1 and Claude Mythos 5.1 System Card · 8.7 · reviewed 2026-10-18	Published configuration Effort: Not specified	lab self-report Terminal-Bench coding slot admits version 4.0 only. Earlier versions remain stored and are not mixed into that slot.	Reviewed 2026-10-18
Terminal-Bench-Science · 0.1	Coding	52.6% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. Argon self-computed with 6x verifier timeout to address verification timeout issues. Other models from the official public leaderboard. Modified verifier timeout is excluded from matched comparison. Provider-published launch claim, not independent measurement by Google for every row. Argon self-computed with 6x verifier timeout to address verification timeout issues. Other models from the official public leaderboard. Modified verifier timeout is excluded from matched comparison. Methodology https://deepmind.google/models/evals-methodology/gemini-4-argon, SHA256 ff1df6bdeddc4c0f48840c09a8a7813b10ae7ad9e053892da68dabf64f09bff7. Preserve source rounding. Methodology says capabilities as of September 2026 and results as of October 2026; review date is source retrieval, not evaluation date. Comparison limit: Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison. Google Gemini 4 Argon launch and evaluation methodology · Launch grid row 10: Terminal-Bench Science 0.1 / Claude Fable 5.1; methodology Additional Details · reviewed 2026-09-30	Published configuration Effort: Not specified	lab self-report Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison.	Reviewed 2026-09-30
Toolathlon · Verified June2026	Agentic	77.8% Reported settings & source Pass@1;108tasks/three trials; internal harness; max effort; Fable safeguards+Opus4.8fallback; Opus safeguards/fallback disabled; pinned containers/data. Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures. Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.15.5.A · reviewed 2026-10-18	Published configuration Effort: Max	lab self-report System card section8.15.5 confirms11of324trials were partly or fully completed by Opus4.8fallback; actual mixed-model execution, not merely available fallback.	Reviewed 2026-10-18
Toolathlon · Verified June2026	Agentic	81.5% Reported settings & source Pass@3;108tasks/three trials; internal harness; max effort; Fable safeguards+Opus4.8fallback; Opus safeguards/fallback disabled; pinned containers/data. Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures. Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.15.5.A · reviewed 2026-10-18	Published configuration Effort: Max	lab self-report System card section8.15.5 confirms11of324trials were partly or fully completed by Opus4.8fallback; actual mixed-model execution, not merely available fallback.	Reviewed 2026-10-18
Toolathlon · Verified June2026	Agentic	73.1% Reported settings & source Pass³;108tasks/three trials; internal harness; max effort; Fable safeguards+Opus4.8fallback; Opus safeguards/fallback disabled; pinned containers/data. Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures. Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.15.5.A · reviewed 2026-10-18	Published configuration Effort: Max	lab self-report System card section8.15.5 confirms11of324trials were partly or fully completed by Opus4.8fallback; actual mixed-model execution, not merely available fallback.	Reviewed 2026-10-18
Toolathlon · Verified June2026	Agentic	23.7 turns Reported settings & source average turns;108tasks/three trials; internal harness; max effort; Fable safeguards+Opus4.8fallback; Opus safeguards/fallback disabled; pinned containers/data. Fable is the safeguarded deployed configuration; selected tasks may use disclosed Opus fallback, except evaluations explicitly counting safety blocks as failures. Claude Fable 5.1 and Claude Mythos 5.1 System Card · Table8.15.5.A · reviewed 2026-10-18	Published configuration Effort: Max	lab self-report System card section8.15.5 confirms11of324trials were partly or fully completed by Opus4.8fallback; actual mixed-model execution, not merely available fallback.	Reviewed 2026-10-18
Vals Finance Agent · 2	Supporting evidence	58.9% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. Results sourced from Vals AI. Provider-published launch claim, not independent measurement by Google for every row. Results sourced from Vals AI. Methodology https://deepmind.google/models/evals-methodology/gemini-4-argon, SHA256 ff1df6bdeddc4c0f48840c09a8a7813b10ae7ad9e053892da68dabf64f09bff7. Preserve source rounding. Methodology says capabilities as of September 2026 and results as of October 2026; review date is source retrieval, not evaluation date. Comparison limit: Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison. Google Gemini 4 Argon launch and evaluation methodology · Launch grid row 3: Vals Finance Agent 2 / Claude Fable 5.1; methodology Additional Details · reviewed 2026-09-30	Published configuration Effort: Not specified	lab self-report Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison.	Reviewed 2026-09-30
Vals Index	Supporting evidence	65.8% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. Vals AI composite, weighted by contribution to US GDP; overlapping component benchmarks do not add an aggregate ranking vote. Provider-published launch claim, not independent measurement by Google for every row. Vals AI composite, weighted by contribution to US GDP; overlapping component benchmarks do not add an aggregate ranking vote. Methodology https://deepmind.google/models/evals-methodology/gemini-4-argon, SHA256 ff1df6bdeddc4c0f48840c09a8a7813b10ae7ad9e053892da68dabf64f09bff7. Preserve source rounding. Methodology says capabilities as of September 2026 and results as of October 2026; review date is source retrieval, not evaluation date. Comparison limit: Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison. Google Gemini 4 Argon launch and evaluation methodology · Launch grid row 1: Vals Index / Claude Fable 5.1; methodology Additional Details · reviewed 2026-09-30	Published configuration Effort: Not specified	lab self-report Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison.	Reviewed 2026-09-30
Vibe Code Bench · 1.1	Supporting evidence	90.3% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. Results sourced from the official Vals AI public leaderboard. Provider-published launch claim, not independent measurement by Google for every row. Results sourced from the official Vals AI public leaderboard. Methodology https://deepmind.google/models/evals-methodology/gemini-4-argon, SHA256 ff1df6bdeddc4c0f48840c09a8a7813b10ae7ad9e053892da68dabf64f09bff7. Preserve source rounding. Methodology says capabilities as of September 2026 and results as of October 2026; review date is source retrieval, not evaluation date. Comparison limit: Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison. Google Gemini 4 Argon launch and evaluation methodology · Launch grid row 7: Vibe Code Bench 1.1 / Claude Fable 5.1; methodology Additional Details · reviewed 2026-09-30	Published configuration Effort: Not specified	lab self-report Provider-published claim. Independent source results are admitted separately with exact checkpoint, effort and compatible protocol; this grid does not establish a matched comparison.	Reviewed 2026-09-30
GDPval-AA	Agentic	—	—	—	—
LiveCodeBench	Coding	—	—	—	—
LMArena Text Arena	Human pref	—	—	—	—
MMLU-Pro	Knowledge	—	—	—	—
OSWorld-Verified	Agentic	—	—	—	—
SWE-bench Verified	Agentic	—	—	—	—
Terminal-Bench 2.1	Agentic	—	—	—	—