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
GDPval-AA · 2	Agentic	1835 Reported settings & source Artificial Analysis; xhigh effort; same release board snapshot. 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 · 8.15.3 · reviewed 2026-10-18	Published configuration Effort: XHigh	lab self-report No matched opponent in this evaluation unit	Reviewed 2026-10-18
GDPval-AA · 2	Agentic	1735 Reported settings & source Grok 4.7 XHigh; Grok 4.6 High; Claude Fable 5.1 Max; GPT-6 Astra Max. GDPval launch chart. Launch chart rounded Elo. Original evaluator: https://artificialanalysis.ai/evaluations/gdpval-aa Comparison limit: Secondary Artificial Analysis leaderboard report; retain the original evaluator once, without treating the launch reprint as additional evidence. Grok 4.7 launch comparison · Professional knowledge work: GDPval chart · reviewed 2026-09-21	Published configuration Effort: Max	lab self-report Secondary Artificial Analysis leaderboard report; retain the original evaluator once, without treating the launch reprint as additional evidence.	Reviewed 2026-09-21
GMMLU	Knowledge	94% Reported settings & source Mean accuracy42languages; adaptive max; one trial; no tools/custom system prompts. 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 · 8.18.1 · reviewed 2026-10-18	Published configuration Effort: Not specified contributes to capability	lab self-report	Reviewed 2026-10-18
GPQA Diamond	Hard reasoning	93.737%	GPQA Diamond reported Effort: Not specified contributes to capability	independent repro	2026-10-20
GPQA Diamond · not specified	Hard reasoning	93.7% Reported settings & source Maximum reported across reasoning efforts; OpenAI research environment or API Provider-published result; comparator measurements are not automatically independently reproduced. GPT-6 Astra: A new generation of intelligence · Academic table / GPQA Diamond / Claude Fable 5.1 · reviewed 2026-09-06	Published configuration Effort: Not specified contributes to capability	lab self-report	Reviewed 2026-09-06
GraphWalks · 256K to 1M BFS F1	Supporting evidence	65% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. All models self-computed. 200 problems with context length between 256K and 1M tokens. BFS F1, not pass rate. Provider-published launch claim, not independent measurement by Google for every row. All models self-computed. 200 problems with context length between 256K and 1M tokens. BFS F1, not pass rate. 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 14: GraphWalks 256K to 1M BFS F1 / 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
GraphWalks · up to 128K BFS F1	Supporting evidence	91.4% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. All models self-computed. 650 items with context length up to 128K tokens. BFS F1, not pass rate. Provider-published launch claim, not independent measurement by Google for every row. All models self-computed. 650 items with context length up to 128K tokens. BFS F1, not pass rate. 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 13: GraphWalks up to 128K BFS F1 / 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
Harvey Legal Agent Benchmark	Supporting evidence	6.7% Reported settings & source Grok 4.7 XHigh (DeepSWE: High); Grok 4.6 High; GPT-5.6 Sol Max; Claude Fable 5.1 Max. Launch comparison; per-model agent harness, evaluation budget and rerun provenance are not specified. Official launch table. Effort follows the column header except the Grok 4.7 DeepSWE asterisk, which explicitly means High. Original evaluator: https://www.vals.ai/benchmarks/hlab Comparison limit: Secondary Harvey leaderboard report; not an additional independent evaluation. Use the original Vals AI evaluation with its reviewed effort settings. Grok 4.7 launch comparison · Model Improvements table: Harvey Legal Agent Benchmark · reviewed 2026-09-21	Published configuration Effort: Max	lab self-report Secondary Harvey leaderboard report; not an additional independent evaluation. Use the original Vals AI evaluation with its reviewed effort settings.	Reviewed 2026-09-21
Harvey's Legal Agent Benchmark · 1	Supporting evidence	6.7% 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 4: Harvey's Legal Agent Benchmark 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
HealthBench	Supporting evidence	66.7% Reported settings & source Raw rubric score; adaptive max; five trials; no tools/custom system prompt; Opus4.8grader; Fable5.1 safety fallback toOpus5. 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 · 8.17 · reviewed 2026-10-18	Published configuration Effort: Not specified	lab self-report Narrow specialist biological, medical or security evaluation; preserved as raw evidence outside general capability scoring.	Reviewed 2026-10-18
HealthBench	Supporting evidence	60% Reported settings & source Length-adjusted score using GPT5.5card method; otherwise raw evaluation configuration. 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 · 8.17.1 · reviewed 2026-10-18	Published configuration Effort: Not specified	lab self-report Narrow specialist biological, medical or security evaluation; preserved as raw evidence outside general capability scoring.	Reviewed 2026-10-18
HealthBench Professional	Supporting evidence	74.2% Reported settings & source Raw rubric score; adaptive max; five trials; no tools/custom system prompt; Opus4.8grader; Fable5.1 safety fallback toOpus5. 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 · 8.17 · reviewed 2026-10-18	Published configuration Effort: Not specified	lab self-report Narrow specialist biological, medical or security evaluation; preserved as raw evidence outside general capability scoring.	Reviewed 2026-10-18
HealthBench Professional	Supporting evidence	62.1% Reported settings & source Length-adjusted score; HealthBench Professional paper method; no tools; Opus4.8grader; five trials. 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 · Table8.1.A;8.17.2 · reviewed 2026-10-18	Published configuration Effort: Not specified	lab self-report Narrow specialist biological, medical or security evaluation; preserved as raw evidence outside general capability scoring.	Reviewed 2026-10-18
HealthBench Professional	Supporting evidence	62.1% Reported settings & source Grok 4.7 XHigh (DeepSWE: High); Grok 4.6 High; GPT-5.6 Sol Max; Claude Fable 5.1 Max. Launch comparison; per-model agent harness, evaluation budget and rerun provenance are not specified. Official launch table. Effort follows the column header except the Grok 4.7 DeepSWE asterisk, which explicitly means High. Comparison limit: The launch table does not establish matching agent harnesses and evaluation settings. Retained as a provider claim; not a new comparable evaluation. Grok 4.7 launch comparison · Model Improvements table: HealthBench Professional · reviewed 2026-09-21	Published configuration Effort: Max	lab self-report The launch table does not establish matching agent harnesses and evaluation settings. Retained as a provider claim; not a new comparable evaluation.	Reviewed 2026-09-21
HealthBench Professional (length-adjusted) · not specified	Supporting evidence	58.1% Reported settings & source Maximum reported across reasoning efforts; OpenAI research environment or API; official paper scoring; length-adjusted; OpenAI reproduction; GPT-5.4 grader; unclipped; Opus5 fallback for provider refusals Provider-published result; comparator measurements are not automatically independently reproduced. GPT-6 Astra: A new generation of intelligence · Science And Health table / HealthBench Professional (length-adjusted) / Claude Fable 5.1 · reviewed 2026-09-06	Published configuration Effort: Not specified	lab self-report Narrow specialist biological, medical or security evaluation; preserved as raw evidence outside general capability scoring.	Reviewed 2026-09-06
Humanity's Last Exam	Hard reasoning	60.9%	HLE no tools Effort: Not specified	lab self-report Legacy self-report lacks a reviewed comparison configuration	2026-09-01
Humanity's Last Exam	Hard reasoning	65%	HLE with tools Effort: Not specified	lab self-report Legacy self-report lacks a reviewed comparison configuration	2026-09-01
Humanity’s Last Exam	Hard reasoning	60.9% Reported settings & source Full2500questions; no tools; auto thinking;1Mtotal token cap; no compaction; Opus4.6grader; restricted fetch and contamination review for tools. 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 · Table 8.1.A;8.12.1 · reviewed 2026-10-18	Published configuration Effort: Auto thinking contributes to capability	lab self-report	Reviewed 2026-10-18
Humanity’s Last Exam	Hard reasoning	65% Reported settings & source Full2500questions; with tools; auto thinking;1Mtotal token cap; no compaction; Opus4.6grader; restricted fetch and contamination review for tools. 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 · Table 8.1.A;8.12.1 · reviewed 2026-10-18	Published configuration Effort: Auto thinking contributes to capability	lab self-report	Reviewed 2026-10-18
Humanity's Last Exam (w/ tools) · not specified	Hard reasoning	65% Reported settings & source Maximum reported across reasoning efforts; OpenAI research environment or API; tools enabled Provider-published result; comparator measurements are not automatically independently reproduced. GPT-6 Astra: A new generation of intelligence · Academic table / Humanity's Last Exam (w/ tools) / Claude Fable 5.1 · reviewed 2026-09-06	Published configuration Effort: Not specified contributes to capability	lab self-report	Reviewed 2026-09-06
Humanity's Sixth Sense	Supporting evidence	40.8%	HSS · unspecified Effort: unspecified Reported settings Full 522-task pass@1, task mean of three attempts; every rubric criterion must pass. 95% task-cluster bootstrap CI. Claude-Opus-5 judge. Scale AI + Elorian. Unversioned board; source hashes identify captures. Display only. Excluded from weighted Overall. Source-recorded date is the capture date, not a proven evaluation date.	official board Supporting evidence outside the reviewed capability core	2026-10-22
Internal Database Migration Tasks · not specified	Supporting evidence	57.8% Reported settings & source Maximum reported across reasoning efforts; OpenAI research environment or API Provider-published result; comparator measurements are not automatically independently reproduced. GPT-6 Astra: A new generation of intelligence · Coding table / Internal Database Migration Tasks / Claude Fable 5.1 · reviewed 2026-09-06	Published configuration Effort: Not specified	lab self-report Composite index or publisher-specific internal evaluation lacks a stable general-capability comparison unit.	Reviewed 2026-09-06
LABBench · 2	Supporting evidence	68.6% Reported settings & source Comparator maximum available thinking/reasoning when reported, otherwise best available result; exact setting not identified by this grid. All models self-computed with Linux terminal, pre-installed bioinformatics tools, Python, R and internet access. Provider-published launch claim, not independent measurement by Google for every row. All models self-computed with Linux terminal, pre-installed bioinformatics tools, Python, R and internet access. 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 11: LABBench 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
Legal Agent Benchmark · 120-task held-out subset	Supporting evidence	16.7% Reported settings & source all-pass; Artificial Analysis harness; xhigh effort. 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 · 8.15.2 · reviewed 2026-10-18	Published configuration Effort: XHigh	lab self-report Supporting evidence outside the reviewed capability core	Reviewed 2026-10-18
Legal Agent Benchmark · 120-task held-out subset	Supporting evidence	93.3% Reported settings & source criterion-pass; Artificial Analysis harness; xhigh effort. 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 · 8.15.2 · reviewed 2026-10-18	Published configuration Effort: XHigh	lab self-report Supporting evidence outside the reviewed capability core	Reviewed 2026-10-18