Model comparison
Claude Fable 5.1 vs Sonar Reasoning Pro
Claude Fable 5.1 has enough public results to be ranked (#2); Sonar Reasoning Pro does not yet, so treat this comparison as directional.
Last verified . 0 shared benchmarks.
PerplexitySummary
- Sonar Reasoning Pro is cheaper at $2 / $8 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
- Claude Fable 5.1 accepts more context: 1M tokens versus 128K.
Side by side
| Claude Fable 5.1 | Sonar Reasoning Pro | |
|---|---|---|
| Provider | Anthropic | Perplexity |
| Noometry Index | 69.0 | — |
| Released | 2026-09-01 | 2024-01-01 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 128K |
| Max output | 128K | 4K |
| Input $ / M tokens | $10 | $2 |
| Output $ / M tokens | $50 | $8 |
| Results tracked | 52 | 1 |
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Category by category
Coding Not comparable
Claude Fable 5.1: 74.7 (#1), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| FrontierCode | 50.9% | — |
| CursorBench | 51.8% | — |
| LMArena WebDev | 1744 | — |
| FrontierSWE | 56.3% | — |
| SciCode | 63.1% | — |
| GSO | 88.2% | — |
| WeirdML | 92.9% | — |
| LMArena Coding | 1528 | — |
| MirrorCode | 73.3% | — |
| ALE-Bench | 2,143 | — |
Agentic & Tool Use Not comparable
Claude Fable 5.1: 50.7 (#5), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| APEX-Agents | 68.6% | — |
| Remote Labor Index | 17.9% | — |
| GDP.pdf | 29.6% | — |
| LMArena Search | — | 1139 |
| Vending-Bench 2 | 5,422 | — |
Reasoning Not comparable
Claude Fable 5.1: 76.7 (#7), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| ARC-AGI-2 | 90% | — |
| NYT Connections (extended) | 90% | — |
| ARC-AGI-1 | 97.5% | — |
| CritPt | 31.1% | — |
| Chess Puzzles | 47% | — |
| EBR-Bench | 57.1% | — |
| LMArena Hard Prompts | 1526 | — |
| Mystery Game Puzzles | 58% | — |
| DTBench | 97.6% | — |
| LMCA | 65.5% | — |
| Epoch Capabilities Index | 164.7 | — |
Math Not comparable
Claude Fable 5.1: 89.6 (#4), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 90.2% | — |
| FrontierMath Tier 4 | 87.8% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| LMArena Math | 1525 | — |
| FrontierMath Erdős | 0% | — |
Knowledge Not comparable
Claude Fable 5.1: 69.6 (#6), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| Humanity's Last Exam | 46.5% | — |
| SimpleQA Verified | 70.8% | — |
| LMArena Expert | 1535 | — |
Multimodal Not comparable
Claude Fable 5.1: 53.9 (#4), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| LMArena Vision | 1318 | — |
| Blueprint-Bench 2 | 41.9% | — |
| Furniture Assembly | 70% | — |
| LMArena Document | 1513 | — |
Multilingual Not comparable
Claude Fable 5.1: 59.1 (#3), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| LMArena Non-English | 1507 | — |
| LMArena Chinese | 1586 | — |
| LMArena French | 1525 | — |
| LMArena German | 1500 | — |
| LMArena Japanese | 1543 | — |
| LMArena Korean | 1534 | — |
| LMArena Russian | 1521 | — |
| LMArena Spanish | 1516 | — |
Instruction Following Not comparable
Claude Fable 5.1: 79.2 (#6), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| LMArena Instruction Following | 1517 | — |
Long Context Not comparable
Claude Fable 5.1: 46.7 (#20), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| LMArena Longer Query | 1522 | — |
Writing & Preference Not comparable
Claude Fable 5.1: 79.2 (#2), Sonar Reasoning Pro: —
| Benchmark | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| LMArena Text | 1510 | — |
| LMArena Creative Writing | 1507 | — |
| EQ-Bench Creative Writing | 2162 | — |
| LMArena Multi-Turn | 1492 | — |
Frequently asked questions
Is Claude Fable 5.1 better than Sonar Reasoning Pro?
Claude Fable 5.1 has enough public results to be ranked (#2); Sonar Reasoning Pro does not yet, so treat this comparison as directional.
Which is cheaper, Claude Fable 5.1 or Sonar Reasoning Pro?
Sonar Reasoning Pro is cheaper. It lists at $2 per million input tokens and $8 per million output tokens; Claude Fable 5.1 lists at $10 and $50.
Which has the bigger context window?
Claude Fable 5.1 does, with 1M tokens against 128K.
How many benchmarks do Claude Fable 5.1 and Sonar Reasoning Pro share?
0 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Sonar Reasoning Pro has 1.