Compare / head-to-head
Claude Fable 5vs
GPT-6 Luna
Claude Fable 5 leads 19 of 21 shared benchmarks. GPT-6 Luna is 100x cheaper per token. GPT-6 Luna has the larger context window (1.1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
19 – 2
Claude Fable 5 leads
Cheaper per token
GPT-6 Luna
100x cheaper, input + output
Larger context
GPT-6 Luna
1.1M tokens
Providers
2 providers
Anthropic · OpenAI
Claude Fable 5
Anthropic · released 2026-06-09
textvision
GPT-6 Luna
OpenAI · released 2026-09-22
textvision
Quality
Benchmark matrix
21 shared · 23 only Claude Fable 5 · 1 only GPT-6 Luna| Benchmark | Claude Fable 5 | GPT-6 Luna | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 21 | ||||
| GPQA Diamond | 85.9% ↗epoch run | 90.5% ↗epoch run | -4.6 pt | GPT-6 Luna |
| LMArena Elo | 1504.3 ↗ | 1442.9 ↗ | +61.4 | Claude Fable 5 |
| APEX-Agents (Mercor) | 63.6% ↗ | 44.3% ↗ | +19.3 pt | Claude Fable 5 |
| Chess Puzzles (Epoch AI run) | 41% ↗epoch run | 31% ↗epoch run | +10 pt | Claude Fable 5 |
| FrontierMath Tier 4 v2 (Epoch AI run) | 90.2% ↗epoch run | 56.1% ↗epoch run | +34.1 pt | Claude Fable 5 |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 87% ↗epoch run | 78.9% ↗epoch run | +8.1 pt | Claude Fable 5 |
| Furniture Assembly (Epoch AI run) | 35.8% ↗epoch run | 44.2% ↗epoch run | -8.4 pt | GPT-6 Luna |
| LiveBench Agentic Coding (LiveBench) | 62.2% ↗ | 51.2% ↗ | +11 pt | Claude Fable 5 |
| LiveBench Coding (LiveBench) | 86% ↗ | 79% ↗ | +7 pt | Claude Fable 5 |
| LiveBench Data Analysis (LiveBench) | 80.5% ↗ | 73.4% ↗ | +7.1 pt | Claude Fable 5 |
| LiveBench Instruction Following (LiveBench) | 75.8% ↗ | 55.9% ↗ | +19.9 pt | Claude Fable 5 |
| LiveBench Language (LiveBench) | 90.7% ↗ | 73.8% ↗ | +16.9 pt | Claude Fable 5 |
| LiveBench Mathematics (LiveBench) | 96% ↗ | 89.1% ↗ | +6.9 pt | Claude Fable 5 |
| LiveBench Reasoning (LiveBench) | 89.7% ↗ | 81.8% ↗ | +7.9 pt | Claude Fable 5 |
| LMArena Agent (LMArena) | 0.0821 ↗ | 0.0135 ↗ | +0.1 | Claude Fable 5 |
| LMArena WebDev (LMArena) | 1625.3 ↗ | 1578.7 ↗ | +46.6 | Claude Fable 5 |
| Mystery Game Puzzles (Epoch AI run) | 52% ↗epoch run | 7% ↗epoch run | +45 pt | Claude Fable 5 |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 100% ↗epoch run | 98.9% ↗epoch run | +1.1 pt | Claude Fable 5 |
| SAGE (Vals AI) | 51.9% ↗ | 48.1% ↗ | +3.8 pt | Claude Fable 5 |
| SimpleQA Verified | 70.7% ↗epoch run | 41.4% ↗epoch run | +29.3 pt | Claude Fable 5 |
| Terminal-Bench 4.0 (Vals AI) | 41.4% ↗ | 13.6% ↗ | +27.8 pt | Claude Fable 5 |
| Only Claude Fable 5 reports · 23 | ||||
| SWE-bench Verified | 95% ↗ | not reported | — | — |
| AutomationBench | 17.4% ↗ | not reported | — | — |
| Blueprint-Bench 2 | 38.6% ↗ | not reported | — | — |
| CursorBench | 72.9% ↗ | not reported | — | — |
| DeepSWE v1.1 (Datacurve) | 69.9% ↗ | not reported | — | — |
| EBR-bench (Epoch AI run) | 39.5% ↗epoch run | not reported | — | — |
| FrontierCode (Diamond) | 29.3% ↗ | not reported | — | — |
| FrontierSWE V2 (Proximal Labs) | 47% ↗ | not reported | — | — |
| GDP.pdf | 29.8% ↗ | not reported | — | — |
| GSO Opt@1 (GSO) | 76.5% ↗ | not reported | — | — |
| Legal Agent Benchmark (Harvey's Held-Out Set) | 13.3% ↗ | not reported | — | — |
| LMArena Vision (LMArena) | 1308.8 ↗ | not reported | — | — |
| MirrorCode (Epoch AI run) | 63.9% ↗epoch run | not reported | — | — |
| OfficeQA Pro | 57.9% ↗ | not reported | — | — |
| OSWorld-Verified | 85% ↗ | not reported | — | — |
| OSWorld-Verified (XLANG) | 86% ↗ | not reported | — | — |
| SimpleBench (SimpleBench) | 81.9% ↗ | not reported | — | — |
| SWE-Bench Pro | 80% ↗ | not reported | — | — |
| SWE-rebench 2026-05-15 to 2026-07-01 (Nebius) | 64.5% ↗ | not reported | — | — |
| tau2-bench Banking Knowledge (Sierra) | 39.7% ↗ | not reported | — | — |
| Terminal-Bench 2.1 | 84.3% ↗ | not reported | — | — |
| Vending-Bench 2 (Andon Labs) | 5680.26 ↗ | not reported | — | — |
| WeirdML (Håvard Tveit Ihle) | 91.9% ↗ | not reported | — | — |
| Only GPT-6 Luna reports · 1 | ||||
| DeepSWE v1.1 | not reported | 66.6% ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Fable 5 minus GPT-6 Luna in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | Claude Fable 5 | GPT-6 Luna | Edge |
|---|---|---|---|
| Context window | 1M tokens | 1.1M tokens | GPT-6 Luna |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $10 ↗ | $0.1 ↗ | GPT-6 Luna |
| Output price / 1M | $50 ↗ | $0.5 ↗ | GPT-6 Luna |
| Cached input / 1M | $1 ↗ | $0.01 ↗ | GPT-6 Luna |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $60 | $0.6 | GPT-6 Luna |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-06-09 | 2026-09-22 | — |
| Cited benchmark scores | 44 | 22 | — |
Reliability
Provider status
Live from /statusMore matchups
Claude Fable 5 vs …
Models sharing the most benchmarksMore matchups
GPT-6 Luna vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Fable 5 and GPT-6 Luna on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.