Benchmark Almanac

ProofBench v1.1

Claude Fable 5.1 100% leads since September 2026
Not in model cards

Models write Lean 4 proofs of graduate-level theorems from paired natural-language and formal statements. Scored by the share the Lean checker accepts.

Vals says scores are not comparable with earlier revisions. Four systems tied at 100% on October 29th, 2026 among 54, so it is saturated.

Made by
Vals AI
Released
August 2026
Kind
Formal proofs
Level
Expert
Scored
Checked automatically
Answers
Written proof
Tasks
Public, plus a private test set
Strongest model tested
Claude Fable 5.2 #1 on the capability index
Last model added
November 2026
Scores refreshed
November 12th, 2026
54
Entries on its own leaderboard, 52 models we track

4 models share the top score of 100%

Best score per entry from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best. Every run is in the next chart. Names in gray aren't in our model list: fine-tunes, agent systems, products and older models. They don't count toward leaders.

54 entries. Scroll sideways for the rest.

  1. 100.0 AlephProver
  2. 100.0 Claude Fable 5.1
  3. 100.0 Claude Opus 5.5
  4. 100.0 Claude Sonnet 5.5
  5. 100.0 Claude Fable 5.2
  6. 99.0 Claude Opus 5
  7. 99.0 GPT-6 Astra
  8. 99.0 GPT-6.1 Sol
  9. 99.0 Gemini 4 Argon
  10. 95.0 Claude Fable 5
  11. 94.0 Muse Wonder Full
  12. 91.0 Kimi K3.1 Pro
  13. 89.0 Claude Haiku 5.5
  14. 87.0 Kimi K3
  15. 86.0 Aristotle
  16. 84.0 Muse Wonder
  17. 83.0 GPT-5.6 Sol
  18. 83.0 GPT-6 Sol
  19. 77.0 Claude Sonnet 5
  20. 75.0 Tencent Hy4 preview
  21. 74.0 GPT-5.6 Terra
  22. 70.0 MiMo-V2.6 Pro
  23. 64.0 GPT-6 Luna
  24. 63.0 MiMo-V2.6 Flash
  25. 61.0 Ember-1
  26. 60.0 GPT-5.6 Luna
  27. 58.0 Qwen 3.8 Max
  28. 58.0 Gemini 3.7 Flash
  29. 58.0 Muse Spark 1.3
  30. 56.0 DeepSeek V4 Flash 0731
  31. 54.0 DeepSeek V4.1 Flash
  32. 51.0 Grok 4.6
  33. 50.0 DeepSeek V4 Pro 0813
  34. 49.0 GLM-5.3
  35. 48.0 Gemini 3.8 Flash
  36. 43.0 Muse Spark 1.2
  37. 42.0 Step 5 Preview
  38. 31.0 Gemini 3.5 Flash
  39. 31.0 Grok 4.5
  40. 26.0 Gemini 3.1 Pro
  41. 26.0 Grok 4.7
  42. 22.0 MiMo-V2.5-Pro
  43. 21.0 GLM-5.3-Flash
  44. 18.0 MiniMax-M3
  45. 18.0 Beam 1.0
  46. 16.0 MiMo-V2.5
  47. 16.0 DeepSeek-V4-Pro
  48. 16.0 Qwen 3.8 27B
  49. 10.0 Mistral Large 4 Preview
  50. 9.00 Mistral Medium 3.5
  51. 6.00 Inkling-Small
  52. 3.00 Mercury 2.5
  53. 0.0 Inkling
  54. 0.0 Nemotron 3.5 Lightning 30B-A3B
  1. 1 AlephProver 100%
  2. 2 Claude Fable 5.1 100%
  3. 3 Claude Opus 5.5 100%
  4. 4 Claude Sonnet 5.5 100%
  5. 5 Claude Fable 5.2 100%
  6. 6 Claude Opus 5 99%
  7. 7 GPT-6 Astra 99%
  8. 8 GPT-6.1 Sol 99%
  9. 9 Gemini 4 Argon 99%
  10. 10 Claude Fable 5 95%
  11. 11 Muse Wonder Full 94%
  12. 12 Kimi K3.1 Pro 91%
  13. 13 Claude Haiku 5.5 89%
  14. 14 Kimi K3 87%
  15. 15 Aristotle 86%
  16. 16 Muse Wonder 84%
  17. 17 GPT-5.6 Sol 83%
  18. 18 GPT-6 Sol 83%
  19. 19 Claude Sonnet 5 77%
  20. 20 Tencent Hy4 preview 75%
  21. 21 GPT-5.6 Terra 74%
  22. 22 MiMo-V2.6 Pro 70%
  23. 23 GPT-6 Luna 64%
  24. 24 MiMo-V2.6 Flash 63%
  25. 25 Ember-1 61%
  26. 26 GPT-5.6 Luna 60%
  27. 27 Qwen 3.8 Max 58%
  28. 28 Gemini 3.7 Flash 58%
  29. 29 Muse Spark 1.3 max 58%
  30. 30 DeepSeek V4 Flash 0731 56%
  31. 31 DeepSeek V4.1 Flash 54%
  32. 32 Grok 4.6 51%
  33. 33 DeepSeek V4 Pro 0813 50%
  34. 34 GLM-5.3 49%
  35. 35 Gemini 3.8 Flash 48%
  36. 36 Muse Spark 1.2 43%
  37. 37 Step 5 Preview 42%
  38. 38 Gemini 3.5 Flash 31%
  39. 39 Grok 4.5 31%
  40. 40 Gemini 3.1 Pro 26%
  41. 41 Grok 4.7 26%
  42. 42 MiMo-V2.5-Pro 22%
  43. 43 GLM-5.3-Flash 21%
  44. 44 MiniMax-M3 18%
  45. 45 Beam 1.0 18%
  46. 46 MiMo-V2.5 16%
  47. 47 DeepSeek-V4-Pro 16%
  48. 48 Qwen 3.8 27B 16%
  49. 49 Mistral Large 4 Preview 10%
  50. 50 Mistral Medium 3.5 9.00%
  51. 51 Inkling-Small 6.00%
  52. 52 Mercury 2.5 3.00%
  53. 53 Inkling 0%
  54. 54 Nemotron 3.5 Lightning 30B-A3B 0%

Source: Official ProofBench v1.1 leaderboard

#EntryScoreSettingDateSource
1 AlephProver 100% Official leaderboard
2 Claude Fable 5.1 100% Sep 2026 Official leaderboard
3 Claude Opus 5.5 100% Sep 2026 Official leaderboard
4 Claude Sonnet 5.5 100% Sep 2026 Official leaderboard
5 Claude Fable 5.2 100% Nov 2026 Official leaderboard
6 Claude Opus 5 99% Jul 2026 Official leaderboard
7 GPT-6 Astra 99% Sep 2026 Official leaderboard
8 GPT-6.1 Sol 99% Sep 2026 Official leaderboard
9 Gemini 4 Argon 99% Sep 2026 Official leaderboard
10 Claude Fable 5 95% Jun 2026 Official leaderboard
11 Muse Wonder Full 94% Oct 2026 Official leaderboard
12 Kimi K3.1 Pro 91% Oct 2026 Official leaderboard
13 Claude Haiku 5.5 89% Oct 2026 Official leaderboard
14 Kimi K3 87% Jul 2026 Official leaderboard
15 Aristotle 86% Official leaderboard
16 Muse Wonder 84% Oct 2026 Official leaderboard
17 GPT-5.6 Sol 83% Jul 2026 Official leaderboard
18 GPT-6 Sol 83% Sep 2026 Official leaderboard
19 Claude Sonnet 5 77% Jun 2026 Official leaderboard
20 Tencent Hy4 preview 75% Aug 2026 Official leaderboard
21 GPT-5.6 Terra 74% Jul 2026 Official leaderboard
22 MiMo-V2.6 Pro 70% Sep 2026 Official leaderboard
23 GPT-6 Luna 64% Sep 2026 Official leaderboard
24 MiMo-V2.6 Flash 63% Sep 2026 Official leaderboard
25 Ember-1 61% Sep 2026 Official leaderboard
26 GPT-5.6 Luna 60% Jul 2026 Official leaderboard
27 Qwen 3.8 Max 58% Aug 2026 Official leaderboard
28 Gemini 3.7 Flash 58% Aug 2026 Official leaderboard
29 Muse Spark 1.3 58% max Sep 2026 Official leaderboard
30 DeepSeek V4 Flash 0731 56% Jul 2026 Official leaderboard
31 DeepSeek V4.1 Flash 54% Sep 2026 Official leaderboard
32 Grok 4.6 51% Aug 2026 Official leaderboard
33 DeepSeek V4 Pro 0813 50% Aug 2026 Official leaderboard
34 GLM-5.3 49% Aug 2026 Official leaderboard
35 Gemini 3.8 Flash 48% Sep 2026 Official leaderboard
36 Muse Spark 1.2 43% Aug 2026 Official leaderboard
37 Step 5 Preview 42% Sep 2026 Official leaderboard
38 Gemini 3.5 Flash 31% May 2026 Official leaderboard
39 Grok 4.5 31% Jul 2026 Official leaderboard
40 Gemini 3.1 Pro 26% Feb 2026 Official leaderboard
41 Grok 4.7 26% Sep 2026 Official leaderboard
42 MiMo-V2.5-Pro 22% Apr 2026 Official leaderboard
43 GLM-5.3-Flash 21% Aug 2026 Official leaderboard
44 MiniMax-M3 18% Jun 2026 Official leaderboard
45 Beam 1.0 18% Oct 2026 Official leaderboard
46 MiMo-V2.5 16% Apr 2026 Official leaderboard
47 DeepSeek-V4-Pro 16% Apr 2026 Official leaderboard
48 Qwen 3.8 27B 16% Aug 2026 Official leaderboard
49 Mistral Large 4 Preview 10% Oct 2026 Official leaderboard
50 Mistral Medium 3.5 9.00% Apr 2026 Official leaderboard
51 Inkling-Small 6.00% Jul 2026 Official leaderboard
52 Mercury 2.5 3.00% Sep 2026 Official leaderboard
53 Inkling 0% Jul 2026 Official leaderboard
54 Nemotron 3.5 Lightning 30B-A3B 0% Aug 2026 Official leaderboard

Accuracy against latency

The Vals scatter chart with its x axis switched from Cost to Latency: mean time per test against accuracy, on a log scale. The line joins the runs that no other run beats on both measures. We redrew this chart from the numbers on the official leaderboard.

0% 20% 40% 60% 80% 100% 1001,00010K Latency (mean per test) (s), log scale, lower is better Accuracy Gemini 3.1 Pro: Accuracy 26%, latency (mean per test) 889 s MiMo-V2.5: Accuracy 16%, latency (mean per test) 1,256 s MiMo-V2.5-Pro: Accuracy 22%, latency (mean per test) 1,177 s DeepSeek-V4-Pro: Accuracy 16%, latency (mean per test) 423 s Mistral Medium 3.5: Accuracy 9%, latency (mean per test) 479 s Gemini 3.5 Flash: Accuracy 31%, latency (mean per test) 394 s MiniMax-M3: Accuracy 18%, latency (mean per test) 719 s Claude Fable 5: Accuracy 95%, latency (mean per test) 823 s Claude Sonnet 5: Accuracy 77%, latency (mean per test) 898 s Grok 4.5: Accuracy 31%, latency (mean per test) 669 s GPT-5.6 Luna: Accuracy 60%, latency (mean per test) 514 s GPT-5.6 Sol: Accuracy 83%, latency (mean per test) 520 s GPT-5.6 Terra: Accuracy 74%, latency (mean per test) 777 s Inkling: Accuracy 0%, latency (mean per test) 436 s Inkling-Small: Accuracy 6%, latency (mean per test) 507 s Kimi K3: Accuracy 87%, latency (mean per test) 2,071 s Claude Opus 5: Accuracy 99%, latency (mean per test) 591 s DeepSeek V4 Flash 0731: Accuracy 56%, latency (mean per test) 934 s Qwen 3.8 Max: Accuracy 58%, latency (mean per test) 1,868 s Muse Spark 1.2: Accuracy 43%, latency (mean per test) 469 s Nemotron 3.5 Lightning 30B-A3B: Accuracy 0%, latency (mean per test) 919 s Grok 4.6: Accuracy 51%, latency (mean per test) 862 s DeepSeek V4 Pro 0813: Accuracy 50%, latency (mean per test) 732 s Gemini 3.7 Flash: Accuracy 58%, latency (mean per test) 424 s GLM-5.3: Accuracy 49%, latency (mean per test) 2,543 s Qwen 3.8 27B: Accuracy 16%, latency (mean per test) 1,454 s GLM-5.3-Flash: Accuracy 21%, latency (mean per test) 4,275 s Tencent Hy4 preview: Accuracy 75%, latency (mean per test) 1,374 s Claude Fable 5.1: Accuracy 100%, latency (mean per test) 478 s Gemini 3.8 Flash: Accuracy 48%, latency (mean per test) 369 s Muse Spark 1.3 (max): Accuracy 58%, latency (mean per test) 569 s Muse Spark 1.3: Accuracy 55%, latency (mean per test) 534 s GPT-6 Astra: Accuracy 99%, latency (mean per test) 308 s Mercury 2.5: Accuracy 3%, latency (mean per test) 202 s DeepSeek V4.1 Flash: Accuracy 54%, latency (mean per test) 547 s Step 5 Preview: Accuracy 42%, latency (mean per test) 2,314 s Grok 4.7: Accuracy 26%, latency (mean per test) 767 s MiMo-V2.6 Flash: Accuracy 63%, latency (mean per test) 3,770 s MiMo-V2.6 Pro: Accuracy 70%, latency (mean per test) 3,694 s Claude Opus 5.5: Accuracy 100%, latency (mean per test) 351 s GPT-6 Luna: Accuracy 64%, latency (mean per test) 451 s GPT-6 Sol: Accuracy 83%, latency (mean per test) 305 s Ember-1: Accuracy 61%, latency (mean per test) 1,269 s Claude Sonnet 5.5: Accuracy 100%, latency (mean per test) 348 s GPT-6.1 Sol: Accuracy 99%, latency (mean per test) 285 s Gemini 4 Argon: Accuracy 99%, latency (mean per test) 380 s Beam 1.0: Accuracy 18%, latency (mean per test) 267 s Mistral Large 4 Preview: Accuracy 10%, latency (mean per test) 1,259 s Claude Haiku 5.5: Accuracy 89%, latency (mean per test) 418 s Muse Wonder: Accuracy 84%, latency (mean per test) 929 s Muse Wonder Full: Accuracy 94%, latency (mean per test) 696 s Kimi K3.1 Pro: Accuracy 91%, latency (mean per test) 496 s AlephProver: Accuracy 100%, latency (mean per test) 1,108 s. Not in our model list Claude Fable 5.2: Accuracy 100%, latency (mean per test) 171 s Claude Fable 5.2 0% 20% 40% 60% 80% 100% 1001,00010K Latency (mean per test) (s), log scale, lower is better Accuracy Gemini 3.1 Pro: Accuracy 26%, latency (mean per test) 889 s MiMo-V2.5: Accuracy 16%, latency (mean per test) 1,256 s MiMo-V2.5-Pro: Accuracy 22%, latency (mean per test) 1,177 s DeepSeek-V4-Pro: Accuracy 16%, latency (mean per test) 423 s Mistral Medium 3.5: Accuracy 9%, latency (mean per test) 479 s Gemini 3.5 Flash: Accuracy 31%, latency (mean per test) 394 s MiniMax-M3: Accuracy 18%, latency (mean per test) 719 s Claude Fable 5: Accuracy 95%, latency (mean per test) 823 s Claude Sonnet 5: Accuracy 77%, latency (mean per test) 898 s Grok 4.5: Accuracy 31%, latency (mean per test) 669 s GPT-5.6 Luna: Accuracy 60%, latency (mean per test) 514 s GPT-5.6 Sol: Accuracy 83%, latency (mean per test) 520 s GPT-5.6 Terra: Accuracy 74%, latency (mean per test) 777 s Inkling: Accuracy 0%, latency (mean per test) 436 s Inkling-Small: Accuracy 6%, latency (mean per test) 507 s Kimi K3: Accuracy 87%, latency (mean per test) 2,071 s Claude Opus 5: Accuracy 99%, latency (mean per test) 591 s DeepSeek V4 Flash 0731: Accuracy 56%, latency (mean per test) 934 s Qwen 3.8 Max: Accuracy 58%, latency (mean per test) 1,868 s Muse Spark 1.2: Accuracy 43%, latency (mean per test) 469 s Nemotron 3.5 Lightning 30B-A3B: Accuracy 0%, latency (mean per test) 919 s Grok 4.6: Accuracy 51%, latency (mean per test) 862 s DeepSeek V4 Pro 0813: Accuracy 50%, latency (mean per test) 732 s Gemini 3.7 Flash: Accuracy 58%, latency (mean per test) 424 s GLM-5.3: Accuracy 49%, latency (mean per test) 2,543 s Qwen 3.8 27B: Accuracy 16%, latency (mean per test) 1,454 s GLM-5.3-Flash: Accuracy 21%, latency (mean per test) 4,275 s Tencent Hy4 preview: Accuracy 75%, latency (mean per test) 1,374 s Claude Fable 5.1: Accuracy 100%, latency (mean per test) 478 s Gemini 3.8 Flash: Accuracy 48%, latency (mean per test) 369 s Muse Spark 1.3 (max): Accuracy 58%, latency (mean per test) 569 s Muse Spark 1.3: Accuracy 55%, latency (mean per test) 534 s GPT-6 Astra: Accuracy 99%, latency (mean per test) 308 s Mercury 2.5: Accuracy 3%, latency (mean per test) 202 s DeepSeek V4.1 Flash: Accuracy 54%, latency (mean per test) 547 s Step 5 Preview: Accuracy 42%, latency (mean per test) 2,314 s Grok 4.7: Accuracy 26%, latency (mean per test) 767 s MiMo-V2.6 Flash: Accuracy 63%, latency (mean per test) 3,770 s MiMo-V2.6 Pro: Accuracy 70%, latency (mean per test) 3,694 s Claude Opus 5.5: Accuracy 100%, latency (mean per test) 351 s GPT-6 Luna: Accuracy 64%, latency (mean per test) 451 s GPT-6 Sol: Accuracy 83%, latency (mean per test) 305 s Ember-1: Accuracy 61%, latency (mean per test) 1,269 s Claude Sonnet 5.5: Accuracy 100%, latency (mean per test) 348 s GPT-6.1 Sol: Accuracy 99%, latency (mean per test) 285 s Gemini 4 Argon: Accuracy 99%, latency (mean per test) 380 s Beam 1.0: Accuracy 18%, latency (mean per test) 267 s Mistral Large 4 Preview: Accuracy 10%, latency (mean per test) 1,259 s Claude Haiku 5.5: Accuracy 89%, latency (mean per test) 418 s Muse Wonder: Accuracy 84%, latency (mean per test) 929 s Muse Wonder Full: Accuracy 94%, latency (mean per test) 696 s Kimi K3.1 Pro: Accuracy 91%, latency (mean per test) 496 s AlephProver: Accuracy 100%, latency (mean per test) 1,108 s. Not in our model list Claude Fable 5.2: Accuracy 100%, latency (mean per test) 171 s Claude Fable 5.2
ModelSettingAccuracyLatency (mean per test)
Claude Fable 5.2 100% 170.86 s
Claude Sonnet 5.5 100% 347.58 s
Claude Opus 5.5 100% 351.04 s
Claude Fable 5.1 100% 478.3 s
AlephProver 100% 1,108 s
GPT-6.1 Sol 99% 284.7 s
GPT-6 Astra 99% 307.87 s
Gemini 4 Argon 99% 380.25 s
Claude Opus 5 99% 590.89 s
Claude Fable 5 95% 822.74 s
Muse Wonder Full 94% 695.56 s
Kimi K3.1 Pro 91% 496.16 s
Claude Haiku 5.5 89% 418.05 s
Kimi K3 87% 2,071 s
Muse Wonder 84% 929.05 s
GPT-6 Sol 83% 304.51 s
GPT-5.6 Sol 83% 520.4 s
Claude Sonnet 5 77% 898.08 s
Tencent Hy4 preview 75% 1,374 s
GPT-5.6 Terra 74% 777.34 s
MiMo-V2.6 Pro 70% 3,694 s
GPT-6 Luna 64% 451.48 s
MiMo-V2.6 Flash 63% 3,770 s
Ember-1 61% 1,269 s
GPT-5.6 Luna 60% 513.69 s
Gemini 3.7 Flash 58% 423.7 s
Muse Spark 1.3 max 58% 568.7 s
Qwen 3.8 Max 58% 1,868 s
DeepSeek V4 Flash 0731 56% 933.98 s
Muse Spark 1.3 55% 534.06 s
DeepSeek V4.1 Flash 54% 546.6 s
Grok 4.6 51% 861.9 s
DeepSeek V4 Pro 0813 50% 732.37 s
GLM-5.3 49% 2,543 s
Gemini 3.8 Flash 48% 368.65 s
Muse Spark 1.2 43% 469.15 s
Step 5 Preview 42% 2,314 s
Gemini 3.5 Flash 31% 394.48 s
Grok 4.5 31% 668.86 s
Grok 4.7 26% 767.18 s
Gemini 3.1 Pro 26% 889.06 s
MiMo-V2.5-Pro 22% 1,177 s
GLM-5.3-Flash 21% 4,275 s
Beam 1.0 18% 266.66 s
MiniMax-M3 18% 718.66 s
DeepSeek-V4-Pro 16% 423.45 s
MiMo-V2.5 16% 1,256 s
Qwen 3.8 27B 16% 1,454 s
Mistral Large 4 Preview 10% 1,259 s
Mistral Medium 3.5 9% 479.05 s
Inkling-Small 6% 507.3 s
Mercury 2.5 3% 201.72 s
Inkling 0% 436.43 s
Nemotron 3.5 Lightning 30B-A3B 0% 919.25 s

The best score, 100%, costs $0.52 a task

Runs on the cost frontier score higher than any run that's cheaper. GPT-6.1 Sol comes within 1 points of the best for $0.23 a task, about half the cost. The costs are the leaderboard's own estimates, so compare them only within this benchmark.

NVIDIA OpenAI Anthropic Cost frontier One model at each effort level
0% 20% 40% 60% 80% 100% $0.01 $0.10 $1.00 $10 Cost per task, log scale Claude Sonnet 5.5 GPT-6.1 Sol Claude Haiku 5.5 GPT-6 Luna Nemotron 3.5 Lightning 30B-A3B 0% 20% 40% 60% 80% 100% $0.01 $0.10 $1.00 $10 Cost per task, log scale Claude Sonnet 5.5 Claude Haiku 5.5

Source: Official ProofBench v1.1 leaderboard

ModelEffortHarnessScoreCost per taskOutput tokens
Claude Fable 5.1 100% $2.70 41,014
Claude Opus 5.5 100% $0.92 34,454
Claude Sonnet 5.5 100% $0.52 38,174
Claude Fable 5.2 100% $0.79 15,270
Claude Opus 5 99% $1.79 47,697
GPT-6 Astra 99% $1.71 9,972
GPT-6.1 Sol 99% $0.23 10,381
Gemini 4 Argon 99% $0.78 16,943
Claude Fable 5 95% $5.23 71,127
Muse Wonder Full 94% $0.86 27,090
Kimi K3.1 Pro 91% $0.47 22,381
Claude Haiku 5.5 89% $0.17 96,721
Kimi K3 87% $1.65 73,191
Muse Wonder 84% $1.31 36,876
GPT-5.6 Sol 83% $1.44 15,223
GPT-6 Sol 83% $0.48 13,630
Claude Sonnet 5 77% $1.37 74,324
Tencent Hy4 preview 75% $0.34 70,300
GPT-5.6 Terra 74% $1.27 15,425
MiMo-V2.6 Pro 70% $0.25 156,532
GPT-6 Luna 64% $0.04 26,528
MiMo-V2.6 Flash 63% $0.12 242,145
Ember-1 61% $1.74 72,478
GPT-5.6 Luna 60% $0.12 18,859
Qwen 3.8 Max 58% $1.50 105,051
Gemini 3.7 Flash 58% $0.56 13,973
Muse Spark 1.3 max 58% $0.48 45,292
DeepSeek V4 Flash 0731 56% $0.16 74,456
Muse Spark 1.3 55% $0.43 36,064
DeepSeek V4.1 Flash 54% $0.13 81,902
Grok 4.6 51% $0.82 38,271
DeepSeek V4 Pro 0813 50% $0.26 24,345
GLM-5.3 49% $2.08 193,607
Gemini 3.8 Flash 48% $0.60 12,218
Muse Spark 1.2 43% $0.44 37,168
Step 5 Preview 42% $0.71 133,184
Gemini 3.5 Flash 31% $0.57 13,387
Grok 4.5 31% $0.57 23,013
Gemini 3.1 Pro 26% $0.78 21,000
Grok 4.7 26% $0.79 14,226
MiMo-V2.5-Pro 22% $0.09 53,015
GLM-5.3-Flash 21% $0.45 333,212
MiniMax-M3 18% $0.42 48,763
Beam 1.0 18% 17,850
MiMo-V2.5 16% $0.06 117,169
DeepSeek-V4-Pro 16% $0.14 16,116
Qwen 3.8 27B 16% $2.30 169,025
Mistral Large 4 Preview 10% $0.33 18,237
Mistral Medium 3.5 9.00% $1.30 18,386
Inkling-Small 6.00% $0.08 25,970
Mercury 2.5 3.00% $0.04 15,608
Inkling 0% $0.20 14,174
Nemotron 3.5 Lightning 30B-A3B 0% $0.02 51,314

2 models have held number one on the official leaderboard since its release in August 2026

Lab claims count from the day the card came out, independent runs from the model’s release.

Anthropic
Own leaderboard Passed 85% in Aug 2026, by Claude Opus 5
Claude Fable 5.1 100%

Source: Official ProofBench v1.1 leaderboard

Claude Fable 5 on the official leaderboard passed 85% in June 2026

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard Best so far
0% 20% 40% 60% 80% 100% 2026 2027 Near the ceiling (85%) Claude Fable 5.1 Claude Fable 5 Gemini 3.5 Flash Gemini 3.1 Pro 0% 20% 40% 60% 80% 100% 2026 2027 Near the ceiling (85%) Claude Fable 5.1 Gemini 3.5 Flash

Source: Official ProofBench v1.1 leaderboard

No lab model card reports it yet

We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.

Versions

We switch the top row to each new version when it comes out. Open it for one row per version. An old version stays in play while people still test it, so whoever first takes it past 85% gets credit for closing it out.

Anthropic OpenAI
ProofBench v1.1 Passed 85% in Aug 2026, by Claude Opus 5
Claude Fable 5.1 100%
ProofBench Replaced by v1.1, Aug 2026
Claude Opus 5 78%
ProofBench v1.1 Passed 85% in Aug 2026, by Claude Opus 5
Claude Fable 5.1 100%

Source: Official leaderboards

Replaces ProofBench

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