Model comparison
Claude Fable 5 vs o3-mini
Claude Fable 5 is the stronger model overall, scoring 66.8 to 36.7 on the Noometry Index. o3-mini costs 10× less per token, which makes it the better buy when Claude Fable 5's lead doesn't matter for your workload.
Last verified . 34 shared benchmarks.
Summary
- They share 34 benchmarks with published results for both. Claude Fable 5 scores higher in 9 categories and o3-mini in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Fable 5 leads 76.8 to 16.3.
- The biggest single-benchmark swing is FrontierMath Tier 4: 90.2% for Claude Fable 5 and 0% for o3-mini.
- o3-mini is cheaper at $1.10 / $4.40 per million input/output tokens, against $10 / $50 for Claude Fable 5.
- Claude Fable 5 accepts more context: 1M tokens versus 200K.
Side by side
| Claude Fable 5 | o3-mini | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 66.8 | 36.7 |
| Released | 2026-06-07 | 2024-12-20 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 200K |
| Max output | 128K | 100K |
| Input $ / M tokens | $10 | $1.10 |
| Output $ / M tokens | $50 | $4.40 |
| Results tracked | 62 | 51 |
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Category by category
Coding Claude Fable 5 leads
Claude Fable 5: 70.6 (#4), o3-mini: 40.8 (#132)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| SciCode | 61% | 39.8% |
| GSO | 78.4% | 1.3% |
| WeirdML | 91.9% | 43.7% |
| LMArena Coding | 1519 | 1378 |
| DeepSWE | 69.9% | — |
| FrontierCode | 53.5% | — |
| Aider Polyglot | — | 60.4% |
| LMArena WebDev | 1625 | — |
| FrontierSWE | 47% | — |
| LiveBench Coding | — | 82.7% |
| MirrorCode | 63.9% | — |
| CadEval | — | 54% |
| ALE-Bench | 2,041 | — |
Agentic & Tool Use Claude Fable 5 leads
Claude Fable 5: 54.0 (#2), o3-mini: 29.6 (#84)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| APEX-Agents | 63.6% | — |
| Remote Labor Index | 16.1% | — |
| τ²-bench Banking | 39.7% | — |
| Cybench | — | 22.5% |
| PostTrainBench | 41.8% | — |
| GBAEval | 74.5% | — |
| GDP.pdf | 30% | — |
| LMArena Search | 1230 | — |
| Vending-Bench 2 | 5,680 | — |
Reasoning Claude Fable 5 leads
Claude Fable 5: 76.8 (#6), o3-mini: 16.3 (#305)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| ARC-AGI-2 | 89.2% | 3% |
| SimpleBench | 81.9% | 22.8% |
| ARC-AGI-1 | 98.5% | 34.5% |
| CritPt | 28.6% | 0.3% |
| Chess Puzzles | 41% | 17% |
| LMArena Hard Prompts | 1508 | 1366 |
| Mystery Game Puzzles | 52% | 7% |
| DTBench | 98.4% | 68.8% |
| LMCA | 61.1% | 19% |
| Epoch Capabilities Index | 162.06 | 140.34 |
| Kagi LLM Benchmark | 91.4% | — |
| NYT Connections (extended) | 92.7% | — |
| EnigmaEval | 39.3% | — |
| EBR-Bench | 39.5% | — |
| LiveBench Reasoning | — | 89.6% |
| LiveBench Data Analysis | — | 70.6% |
| Surface Evolver Bench | 95% | — |
| Bench to the Future 3 | 0.13 | — |
| ForecastBench | — | 59.6 |
| LiveBench | — | 75.9% |
Math Claude Fable 5 leads
Claude Fable 5: 88.5 (#5), o3-mini: 28.1 (#244)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87% | 18.6% |
| FrontierMath Tier 4 | 90.2% | 0% |
| OTIS Mock AIME 2024-2025 | 100% | 76.9% |
| LMArena Math | 1519 | 1396 |
| ProofBench | 95% | — |
| LiveBench Math | — | 77.3% |
| MATH Level 5 | — | 96.5% |
| FrontierMath (Feb 2025 set) | — | 12.4% |
| FrontierMath Erdős | 0% | — |
| FrontierMath Tier 4 (v1) | — | 4.2% |
Knowledge Claude Fable 5 leads
Claude Fable 5: 62.2 (#25), o3-mini: 38.3 (#146)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| GPQA Diamond | 85.9% | 77% |
| SimpleQA Verified | 70.7% | 15.3% |
| LMArena Expert | 1534 | 1364 |
| Confabulations | — | 17.9% |
Multimodal Not comparable
Claude Fable 5: 45.3 (#17), o3-mini: —
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| LMArena Vision | 1324 | — |
| Blueprint-Bench 2 | 38.6% | — |
| Furniture Assembly | 35.8% | — |
| LMArena Document | 1496 | — |
Multilingual Claude Fable 5 leads
Claude Fable 5: 57.3 (#9), o3-mini: 45.7 (#164)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| LMArena Non-English | 1481 | 1319 |
| LMArena Chinese | 1543 | 1379 |
| LMArena French | 1505 | 1334 |
| LMArena German | 1486 | 1303 |
| LMArena Japanese | 1506 | 1286 |
| LMArena Korean | 1488 | 1314 |
| LMArena Russian | 1504 | 1304 |
| LMArena Spanish | 1498 | 1321 |
Instruction Following Claude Fable 5 leads
Claude Fable 5: 78.6 (#8), o3-mini: 75.1 (#72)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| LMArena Instruction Following | 1502 | 1337 |
| LiveBench Instruction Following | — | 84.4% |
Long Context Claude Fable 5 leads
Claude Fable 5: 46.3 (#23), o3-mini: 33.8 (#256)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| LMArena Longer Query | 1509 | 1343 |
| Fiction.LiveBench | — | 50% |
Writing & Preference Claude Fable 5 leads
Claude Fable 5: 75.9 (#5), o3-mini: 50.3 (#182)
| Benchmark | Claude Fable 5 | o3-mini |
|---|---|---|
| LMArena Text | 1491 | 1337 |
| LMArena Creative Writing | 1494 | 1286 |
| LMArena Multi-Turn | 1504 | 1320 |
| Short-Story Creative Writing | — | 61.7% |
| EQ-Bench Creative Writing | 1943 | — |
| EQ-Bench 4 | 1340 | — |
| LiveBench Language | — | 50.7% |
Frequently asked questions
Is Claude Fable 5 better than o3-mini?
Claude Fable 5 is the stronger model overall, scoring 66.8 to 36.7 on the Noometry Index. o3-mini costs 10× less per token, which makes it the better buy when Claude Fable 5's lead doesn't matter for your workload.
Which is cheaper, Claude Fable 5 or o3-mini?
o3-mini is cheaper. It lists at $1.10 per million input tokens and $4.40 per million output tokens; Claude Fable 5 lists at $10 and $50.
Is Claude Fable 5 or o3-mini better for coding?
Claude Fable 5 scores higher on coding benchmarks: 70.6 versus 40.8 in the Noometry coding category.
Which has the bigger context window?
Claude Fable 5 does, with 1M tokens against 200K.
How many benchmarks do Claude Fable 5 and o3-mini share?
34 benchmarks have published results for both models. Claude Fable 5 has 62 scored results on Noometry and o3-mini has 51.