Claude Sonnet 5.5 vs DeepSeek V4.1 Flash: Release Comparison
Comparison of the Claude Sonnet 5.5 and DeepSeek V4.1 Flash 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 Sonnet 5.5 scores highest: Claude Sonnet 5.5 (Adaptive Reasoning, Max Effort, Default Fallback) at 56, against DeepSeek V4.1 Flash (Reasoning, Max Effort) at 39 for DeepSeek V4.1 Flash.
- For output speed, DeepSeek V4.1 Flash is fastest: DeepSeek V4.1 Flash (Non-Reasoning) at 228 t/s, against Claude Sonnet 5.5 (Adaptive Reasoning, Xhigh Effort, Default Fallback) at 171 t/s for Claude Sonnet 5.5.
- For cost per task, DeepSeek V4.1 Flash is cheapest: DeepSeek V4.1 Flash (Non-Reasoning) at $0.15, against Claude Sonnet 5.5 (Adaptive Reasoning, Low Effort, Default Fallback) at $0.41 for Claude Sonnet 5.5.
Intelligence
Artificial Analysis Intelligence Index
Intelligence Index vs. Cost per Intelligence Index Task
Cost per Task (USD, Log Scale)
Cost
Cost per Intelligence Index Task
Speed & Latency
Output Speed
Capability Scores
Capability Indexes
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, Humanity's Last Exam, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, Humanity's Last Exam, AA-LCR v1.1, GDP.pdf, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, MLCR-AA, Humanity's Last Exam, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, CritPt, GDPval-AA v2.1, AA-Briefcase v1.1, Terminal-Bench 4.0 · Higher is better
Incorporates 5 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2.1, AA-Briefcase v1.1, AA-LCR v1.1 · Higher is better
Further details
Input modality | Output modality | Weights | Provider Benchmarks | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Sonnet 5.5 (Adaptive Reasoning, Max Effort, Default Fallback) |  Anthropic | 56 | 57 | 60 | 56 | - | 58 | 61 | $7.60 | $1.5 | $2.00 | $10.00 | $0.20 | $8,977 | 193k | 142k | 411M | - | - | - | - | - | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - |   | |
| Claude Sonnet 5.5 (Adaptive Reasoning, Xhigh Effort, Default Fallback) | Anthropic | 52 | 52 | 56 | 52 | - | 54 | 56 | $2.74 | $1.5 | $2.00 | $10.00 | $0.20 | $2,738 | 74k | 48k | 104M | 171 | 135.07s | 135.07s | 138.00s | 329.29s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) | Anthropic | 47 | 47 | 52 | 49 | - | 48 | 52 | $1.08 | $1.5 | $2.00 | $10.00 | $0.20 | $1,176 | 34k | 18k | 50M | 97 | 10.97s | 10.97s | 16.12s | 187.78s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 41 | 41 | 45 | 44 | - | 42 | 47 | $0.59 | $1.5 | $2.00 | $10.00 | $0.20 | $701 | 19k | 8k | 29M | 115 | 3.79s | 3.79s | 8.16s | 108.81s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| DeepSeek V4.1 Flash (Reasoning, Max Effort) |  DeepSeek | 39 | 45 | 52 | 41 | 41 | 39 | 44 | $0.27 | $0.2 | $0.30 | $1.20 | $0.006 | $477 | 89k | 63k | 253M | 220 | 1.12s | 10.23s | 12.50s | 299.57s | 552B 16B active at inference time | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text |    +16 | |||
| Claude Sonnet 5.5 (Adaptive Reasoning, Low Effort, Default Fallback) | Anthropic | 36 | 37 | 41 | 40 | - | 38 | 44 | $0.41 | $1.5 | $2.00 | $10.00 | $0.20 | $544 | 14k | 5k | 23M | 93 | 1.17s | 1.17s | 6.57s | 95.30s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| DeepSeek V4.1 Flash (Non-Reasoning) | DeepSeek | 25 | 30 | 36 | 30 | - | 25 | 32 | $0.15 | $0.2 | $0.30 | $1.20 | $0.006 | $156 | 34k | 0 | 45M | 228 | 1.01s | 1.01s | 3.20s | 147.34s | 552B 16B active at inference time | 1M | Sep 2026 | - | No | Supports: text and image | Supports: text | | |||