APEX-Agents Original Effort: High 59.7% mercor.com for Claude Fable 5.1 (high) on APEX-Agents Original (opens in a new tab) Archived copy (opens in a new tab) Pass rate Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on APEX-Agents Original APEX-Agents Original Effort: Max 68.6% mercor.com for Claude Fable 5.1 (max) on APEX-Agents Original (opens in a new tab) Archived copy (opens in a new tab) Pass rate Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on APEX-Agents Original AutomationBench 1.0.6 Effort: xHigh 21.3% zapier.com for Claude Fable 5.1 (xhigh) on AutomationBench 1.0.6 (opens in a new tab) Archived copy (opens in a new tab) Task pass rate Reported October 7, 2026 Benchmark leaderboard Zapier Independent Zapier AutomationBench Team Record for Claude Fable 5.1 on AutomationBench 1.0.6 AutomationBench 1.0.6 Effort: Max 22.4% zapier.com for Claude Fable 5.1 (max) on AutomationBench 1.0.6 (opens in a new tab) Archived copy (opens in a new tab) Task pass rate Reported October 7, 2026 Benchmark leaderboard Zapier Independent Zapier AutomationBench Team Record for Claude Fable 5.1 on AutomationBench 1.0.6 BrowseComp 130-question subset — Mercor web research agent Effort: High Configuration: Mercor web research agent, 100 steps, 3 hours 78.3% mercor.com for Claude Fable 5.1 (high) on BrowseComp 130-question subset — Mercor web research agent (opens in a new tab) Archived copy (opens in a new tab) BrowseComp Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on BrowseComp 130-question subset — Mercor web research agent BrowseComp 130-question subset — Mercor web research agent Effort: Max Configuration: Mercor web research agent, 100 steps, 3 hours 85.2% mercor.com for Claude Fable 5.1 (max) on BrowseComp 130-question subset — Mercor web research agent (opens in a new tab) Archived copy (opens in a new tab) BrowseComp Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on BrowseComp 130-question subset — Mercor web research agent Chartography October 2026 leaderboard Effort: Max Reported as: Adaptive/Max 46.2% surgehq.ai for Claude Fable 5.1 (Adaptive/Max) on Chartography October 2026 leaderboard (opens in a new tab) Archived copy (opens in a new tab) Chartography Pass@1 Reported October 7, 2026 Benchmark leaderboard Surge AI Independent Record for Claude Fable 5.1 on Chartography October 2026 leaderboard CharXiv Descriptive and reasoning — Mercor single-shot Effort: High Configuration: Mercor single-shot agent 94.1% mercor.com for Claude Fable 5.1 (high) on CharXiv Descriptive and reasoning — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) CharXiv Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on CharXiv Descriptive and reasoning — Mercor single-shot CharXiv Descriptive and reasoning — Mercor single-shot Effort: Max Configuration: Mercor single-shot agent 95.1% mercor.com for Claude Fable 5.1 (max) on CharXiv Descriptive and reasoning — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) CharXiv Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on CharXiv Descriptive and reasoning — Mercor single-shot CursorBench 3.2.0 Effort: Low 66.2% anthropic.com for Claude Fable 5.1 (low) on CursorBench 3.2.0 (opens in a new tab) CursorBench Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Cursor Record for Claude Fable 5.1 on CursorBench 3.2.0 CursorBench 3.2.0 Effort: Medium 68.0% anthropic.com for Claude Fable 5.1 (medium) on CursorBench 3.2.0 (opens in a new tab) CursorBench Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Cursor Record for Claude Fable 5.1 on CursorBench 3.2.0 CursorBench 3.2.0 Effort: High 69.4% anthropic.com for Claude Fable 5.1 (high) on CursorBench 3.2.0 (opens in a new tab) CursorBench Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Cursor Record for Claude Fable 5.1 on CursorBench 3.2.0 CursorBench 3.2.0 Effort: xHigh 72.8% anthropic.com for Claude Fable 5.1 (xhigh) on CursorBench 3.2.0 (opens in a new tab) CursorBench Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Cursor Record for Claude Fable 5.1 on CursorBench 3.2.0 CursorBench 3.2.0 Effort: Max 73.4% anthropic.com for Claude Fable 5.1 (max) on CursorBench 3.2.0 (opens in a new tab) CursorBench Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Cursor Record for Claude Fable 5.1 on CursorBench 3.2.0 CursorBench 4.0 Effort: Low 45.1% cursor.com for Claude Fable 5.1 (low) on CursorBench 4.0 (opens in a new tab) Archived copy (opens in a new tab) CursorBench Accuracy Reported October 7, 2026 Benchmark leaderboard Cursor Independent Record for Claude Fable 5.1 on CursorBench 4.0 CursorBench 4.0 Effort: Medium 46.8% cursor.com for Claude Fable 5.1 (medium) on CursorBench 4.0 (opens in a new tab) Archived copy (opens in a new tab) CursorBench Accuracy Reported October 7, 2026 Benchmark leaderboard Cursor Independent Record for Claude Fable 5.1 on CursorBench 4.0 CursorBench 4.0 Effort: High 49.2% cursor.com for Claude Fable 5.1 (high) on CursorBench 4.0 (opens in a new tab) Archived copy (opens in a new tab) CursorBench Accuracy Reported October 7, 2026 Benchmark leaderboard Cursor Independent Record for Claude Fable 5.1 on CursorBench 4.0 CursorBench 4.0 Effort: xHigh 51.6% cursor.com for Claude Fable 5.1 (xhigh) on CursorBench 4.0 (opens in a new tab) Archived copy (opens in a new tab) CursorBench Accuracy Reported October 7, 2026 Benchmark leaderboard Cursor Independent Record for Claude Fable 5.1 on CursorBench 4.0 CursorBench 4.0 Effort: Max 51.8% cursor.com for Claude Fable 5.1 (max) on CursorBench 4.0 (opens in a new tab) CursorBench Accuracy Reported September 10, 2026 Benchmark leaderboard Cursor Independent Record for Claude Fable 5.1 on CursorBench 4.0 CWE-bench 1 — Claude Code Effort: High Configuration: Claude Code harness 58.0% cwe-bench.com for Claude Fable 5.1 (high) on CWE-bench 1 — Claude Code (opens in a new tab) Archived copy (opens in a new tab) CWE-bench Programmatic Pass@1 Reported October 7, 2026 Benchmark leaderboard Collinear AI Independent Record for Claude Fable 5.1 on CWE-bench 1 — Claude Code DeepSWE 1.1 Effort: Max 67.4% www-cdn.anthropic.com for Claude Fable 5.1 (max) on DeepSWE 1.1 (opens in a new tab) DeepSWE Pass@1 Reported September 1, 2026 System card Anthropic Self-reported Record for Claude Fable 5.1 on DeepSWE 1.1 DeepSWE 1.1 — Mercor mini-swe-agent, 500 steps Effort: High Configuration: Mercor mini-swe-agent, 500 steps, 2 hours 67.3% mercor.com for Claude Fable 5.1 (high) on DeepSWE 1.1 — Mercor mini-swe-agent, 500 steps (opens in a new tab) Archived copy (opens in a new tab) DeepSWE Pass@1 Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on DeepSWE 1.1 — Mercor mini-swe-agent, 500 steps DeepSWE 1.1 — Mercor mini-swe-agent, 500 steps Effort: Max Configuration: Mercor mini-swe-agent, 500 steps, 2 hours 64.9% mercor.com for Claude Fable 5.1 (max) on DeepSWE 1.1 — Mercor mini-swe-agent, 500 steps (opens in a new tab) Archived copy (opens in a new tab) DeepSWE Pass@1 Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on DeepSWE 1.1 — Mercor mini-swe-agent, 500 steps Finance Agent Benchmark 2 — October 2026 evaluation 58.9% vals.ai for Claude Fable 5.1 on Finance Agent Benchmark 2 — October 2026 evaluation (opens in a new tab) Archived copy (opens in a new tab) Finance Agent Accuracy Reported October 6, 2026 Benchmark leaderboard Vals AI Independent Record for Claude Fable 5.1 on Finance Agent Benchmark 2 — October 2026 evaluation FrontierSWE 2 — October 2026 evaluation Configuration: Proximus harness, 5 trials, 20-hour budget 56.3% frontierswe.com for Claude Fable 5.1 on FrontierSWE 2 — October 2026 evaluation (opens in a new tab) Archived copy (opens in a new tab) FrontierSWE Score Reported October 7, 2026 Benchmark leaderboard Proximal Independent Record for Claude Fable 5.1 on FrontierSWE 2 — October 2026 evaluation Global MMLU Original Effort: Max 94.0% www-cdn.anthropic.com for Claude Fable 5.1 (max) on Global MMLU Original (opens in a new tab) Average accuracy Reported September 1, 2026 System card Anthropic Self-reported Record for Claude Fable 5.1 on Global MMLU Original GPQA Diamond — Mercor single-shot Effort: High Configuration: Mercor single-shot agent 85.2% mercor.com for Claude Fable 5.1 (high) on Graduate-Level Google-Proof Q&A Diamond — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) GPQA Diamond Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on Graduate-Level Google-Proof Q&A Diamond — Mercor single-shot GPQA Diamond — Mercor single-shot Effort: Max Configuration: Mercor single-shot agent 91.4% mercor.com for Claude Fable 5.1 (max) on Graduate-Level Google-Proof Q&A Diamond — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) GPQA Diamond Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on Graduate-Level Google-Proof Q&A Diamond — Mercor single-shot GPQA Diamond — Vals AI harness Configuration: Vals AI harness: mean of zero-shot and few-shot CoT 93.4% vals.ai for Claude Fable 5.1 on Graduate-Level Google-Proof Q&A Diamond — Vals AI harness (opens in a new tab) Archived copy (opens in a new tab) GPQA Diamond Accuracy Reported September 1, 2026 Benchmark leaderboard Vals AI Independent Record for Claude Fable 5.1 on Graduate-Level Google-Proof Q&A Diamond — Vals AI harness HLAB October 2026 evaluation 6.7% vals.ai for Claude Fable 5.1 on Harvey's Legal Agent Benchmark October 2026 evaluation (opens in a new tab) Archived copy (opens in a new tab) HLAB Task Pass Rate Reported October 6, 2026 Benchmark leaderboard Vals AI Independent Record for Claude Fable 5.1 on Harvey's Legal Agent Benchmark October 2026 evaluation Humanity's Last Exam Full set — No tools Effort: Low Configuration: No tools 53.2% anthropic.com for Claude Fable 5.1 (low) on Humanity's Last Exam Full set — No tools (opens in a new tab) Humanity's Last Exam Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Record for Claude Fable 5.1 on Humanity's Last Exam Full set — No tools Humanity's Last Exam Full set — No tools Effort: Medium Configuration: No tools 55.9% anthropic.com for Claude Fable 5.1 (medium) on Humanity's Last Exam Full set — No tools (opens in a new tab) Humanity's Last Exam Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Record for Claude Fable 5.1 on Humanity's Last Exam Full set — No tools Humanity's Last Exam Full set — No tools Effort: High Configuration: No tools 58.0% anthropic.com for Claude Fable 5.1 (high) on Humanity's Last Exam Full set — No tools (opens in a new tab) Humanity's Last Exam Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Record for Claude Fable 5.1 on Humanity's Last Exam Full set — No tools Humanity's Last Exam Full set — No tools Effort: xHigh Configuration: No tools 60.4% anthropic.com for Claude Fable 5.1 (xhigh) on Humanity's Last Exam Full set — No tools (opens in a new tab) Humanity's Last Exam Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Record for Claude Fable 5.1 on Humanity's Last Exam Full set — No tools Humanity's Last Exam Full set — No tools Reported as: no tools Configuration: No tools 60.9% anthropic.com for Claude Fable 5.1 (no tools) on Humanity's Last Exam Full set — No tools (opens in a new tab) Humanity's Last Exam Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Record for Claude Fable 5.1 on Humanity's Last Exam Full set — No tools Humanity's Last Exam Full set — Scale AI evaluation Effort: xHigh 46.5% labs.scale.com for Claude Fable 5.1 (xhigh) on Humanity's Last Exam Full set — Scale AI evaluation (opens in a new tab) Archived copy (opens in a new tab) Humanity's Last Exam Accuracy Reported October 3, 2026 Benchmark leaderboard Scale AI Independent Record for Claude Fable 5.1 on Humanity's Last Exam Full set — Scale AI evaluation Humanity's Last Exam Full set — With tools Reported as: with tools Configuration: With tools 65.0% anthropic.com for Claude Fable 5.1 (with tools) on Humanity's Last Exam Full set — With tools (opens in a new tab) Humanity's Last Exam Accuracy Reported September 1, 2026 Launch post Anthropic Self-reported Record for Claude Fable 5.1 on Humanity's Last Exam Full set — With tools Humanity's Last Exam Text only — Mercor single-shot Effort: High Configuration: Mercor single-shot agent 53.1% mercor.com for Claude Fable 5.1 (high) on Humanity's Last Exam Text only — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) Humanity's Last Exam Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on Humanity's Last Exam Text only — Mercor single-shot Humanity's Last Exam Text only — Mercor single-shot Effort: Max Configuration: Mercor single-shot agent 54.6% mercor.com for Claude Fable 5.1 (max) on Humanity's Last Exam Text only — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) Humanity's Last Exam Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on Humanity's Last Exam Text only — Mercor single-shot Humanity's Last Exam Text only — Scale AI evaluation Effort: xHigh 46.8% labs.scale.com for Claude Fable 5.1 (xhigh) on Humanity's Last Exam Text only — Scale AI evaluation (opens in a new tab) Archived copy (opens in a new tab) Humanity's Last Exam Accuracy Reported October 7, 2026 Benchmark leaderboard Scale AI Independent Record for Claude Fable 5.1 on Humanity's Last Exam Text only — Scale AI evaluation MCP Atlas Public, April 2026 update 87.2% labs.scale.com for Claude Fable 5.1 on MCP Atlas Public, April 2026 update (opens in a new tab) Pass rate Reported September 24, 2026 Benchmark leaderboard Scale AI Independent Record for Claude Fable 5.1 on MCP Atlas Public, April 2026 update MedXpertQA MM — Mercor single-shot Effort: High Configuration: Mercor single-shot agent 79.7% mercor.com for Claude Fable 5.1 (high) on MedXpertQA MM — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on MedXpertQA MM — Mercor single-shot MedXpertQA MM — Mercor single-shot Effort: Max Configuration: Mercor single-shot agent 83.7% mercor.com for Claude Fable 5.1 (max) on MedXpertQA MM — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on MedXpertQA MM — Mercor single-shot MMLU-Pro Original — Mercor single-shot Effort: High Configuration: Mercor single-shot agent 91.5% mercor.com for Claude Fable 5.1 (high) on MMLU-Pro Original — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on MMLU-Pro Original — Mercor single-shot MMLU-Pro Original — Mercor single-shot Effort: Max Configuration: Mercor single-shot agent 93.0% mercor.com for Claude Fable 5.1 (max) on MMLU-Pro Original — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) Accuracy Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on MMLU-Pro Original — Mercor single-shot MMLU-Pro Original — Vals AI harness Configuration: Vals AI harness 92.4% vals.ai for Claude Fable 5.1 on MMLU-Pro Original — Vals AI harness (opens in a new tab) Archived copy (opens in a new tab) Accuracy Reported September 1, 2026 Benchmark leaderboard Vals AI Independent Record for Claude Fable 5.1 on MMLU-Pro Original — Vals AI harness MMMU-Pro 1,730 questions — Mercor single-shot Effort: High Configuration: Mercor single-shot agent 83.9% mercor.com for Claude Fable 5.1 (high) on MMMU-Pro 1,730 questions — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) MMMU-Pro accuracy Setting: Not stated Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on MMMU-Pro 1,730 questions — Mercor single-shot MMMU-Pro 1,730 questions — Mercor single-shot Effort: Max Configuration: Mercor single-shot agent 86.1% mercor.com for Claude Fable 5.1 (max) on MMMU-Pro 1,730 questions — Mercor single-shot (opens in a new tab) Archived copy (opens in a new tab) MMMU-Pro accuracy Setting: Not stated Reported October 7, 2026 Benchmark leaderboard Mercor Independent Record for Claude Fable 5.1 on MMMU-Pro 1,730 questions — Mercor single-shot MMMU-Pro Vals AI harness Configuration: Vals AI harness 90.6% vals.ai for Claude Fable 5.1 on MMMU-Pro Vals AI harness (opens in a new tab) Archived copy (opens in a new tab) MMMU-Pro accuracy Setting: Standard (4 options) Reported September 1, 2026 Benchmark leaderboard Vals AI Independent Record for Claude Fable 5.1 on MMMU-Pro Vals AI harness MILU Original Effort: Max 93.0% www-cdn.anthropic.com for Claude Fable 5.1 (max) on Multi-task Indic Language Understanding Benchmark Original (opens in a new tab) Average accuracy Reported September 1, 2026 System card Anthropic Self-reported Record for Claude Fable 5.1 on Multi-task Indic Language Understanding Benchmark Original