Claude Fable 5.1 vs gpt-oss-20b: Release Comparison
Comparison of the Claude Fable 5.1 and gpt-oss-20b releases: 5 and 2 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 7 models.
- For intelligence, Claude Fable 5.1 scores highest: Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 53, against gpt-oss-20b (low) at 10 for gpt-oss-20b.
- For output speed, gpt-oss-20b is fastest: gpt-oss-20b (low) at 286 t/s, against Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 65 t/s for Claude Fable 5.1.
- For cost per task, gpt-oss-20b is cheapest: gpt-oss-20b (high) at $0.01, against Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) at $2.37 for Claude Fable 5.1.
Intelligence
Artificial Analysis Intelligence Index
Intelligence Index vs. Cost per Intelligence Index Task
Cost
Cost per Intelligence Index Task
Speed & Latency
Output Speed
Capability Scores
Capability Indices
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, Humanity's Last Exam, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, Humanity's Last Exam, AA-LCR v1.1, GDP.pdf, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, MLCR-AA, Humanity's Last Exam, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, CritPt, GDPval-AA v2, AA-Briefcase, Terminal-Bench v4.0 · Higher is better
Incorporates 5 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2, AA-Briefcase, AA-LCR v1.1 · Higher is better
Further details
Input modality | Output modality | Weights | Provider Benchmarks | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) |  Anthropic | 53 | 57 | 60 | 61 | 58 | 57 | 63 | $7.63 | $7.2 | $10.00 | $50.00 | $0.25 | $13,129 | 78k | 47k | 188M | 65 | 234.98s | 234.98s | 242.68s | 766.85s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) | Anthropic | 53 | 56 | 58 | 61 | - | 57 | 62 | $5.98 | $7.2 | $10.00 | $50.00 | $0.25 | $9,063 | 61k | 34k | 121M | 60 | 88.79s | 88.79s | 97.17s | 674.30s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, High Effort, Default Fallback) | Anthropic | 51 | 54 | 56 | 58 | - | 55 | 60 | $3.91 | $7.2 | $10.00 | $50.00 | $0.25 | $5,242 | 38k | 19k | 62M | 54 | 15.85s | 15.85s | 25.13s | 454.21s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 49 | 52 | 54 | 57 | - | 52 | 58 | $2.98 | $7.2 | $10.00 | $50.00 | $0.25 | $3,983 | 28k | 12k | 44M | 54 | 8.69s | 8.69s | 18.01s | 327.02s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) | Anthropic | 47 | 49 | 52 | 54 | - | 49 | 55 | $2.37 | $7.2 | $10.00 | $50.00 | $0.25 | $3,158 | 22k | 8k | 33M | 53 | 4.89s | 4.89s | 14.32s | 268.70s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| gpt-oss-20b (low) |  OpenAI | 10 | - | - | - | - | - | - | - | $0.1 | $0.07 | $0.20 | - | - | - | - | - | 286 | 0.84s | 7.83s | 9.58s | - | 21B 3.6B active at inference time | 131k | Aug 2025 | May 2025 | Yes | Supports: text | Supports: text |    +5 | |||
| gpt-oss-20b (high) | OpenAI | 9 | 7 | 5 | 7 | 7 | 12 | 11 | $0.01 | $0.1 | $0.06 | $0.19 | - | $29 | 18k | 16k | 70M | 236 | 0.77s | 9.22s | 11.34s | 76.54s | 21B 3.6B active at inference time | 131k | Aug 2025 | May 2024 | Yes | Supports: text | Supports: text |    +6 | |||