Loading benchmark catalogue
Compare performance benchmarks, coding intelligence, reasoning evaluations, context limits, and API economics between Claude Opus 5.5 (Anthropic) and DeepSeek V4.1 Flash 1017 (DeepSeek).
| Metric / Capability | Claude Opus 5.5 | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| Developer / Organization | Anthropic | DeepSeek |
| Release Date | 2026-09-22 | 2026-10-17 |
| Deployment / Weights | Proprietary Cloud API | Open Weights |
| Context Window | 1M tokens (1,000,000 tokens) | 1.0M tokens (1,048,576 tokens) |
| Input Pricing (/1M Tokens) | $4 | Free (Open Weights) |
| Output Pricing (/1M Tokens) | $20 | Free (Open Weights) |
| Benchmark / Domain | Claude Opus 5.5 | DeepSeek V4.1 Flash 1017 | Advantage |
|---|---|---|---|
Artificial Analysis Intelligence Index Composite index aggregating 10+ evaluations of general reasoning and knowledge. | 57.6% | 39.5% | Claude Opus 5.5 (+46%) |
Artificial Analysis Coding Agent Index v2.0 Composite index of coding-agent systems (model + harness) across FrontierCode v1.1, SWE-Atlas-QnA, and Terminal-Bench v4. | 61.7% | 46.3% | Claude Opus 5.5 (+33%) |
SWE-bench Pro Harder, contamination-resistant successor to SWE-bench spanning multiple languages. | 89.9% | — | — |
Terminal-Bench 4.0 Sandboxed command-line tasks requiring shell and file-system operation. | 66.4% | 42.3% | Claude Opus 5.5 (+57%) |
ARC-AGI-2 Novel visual grid puzzles requiring abstract rule induction. | 91.7% | — | — |
GPQA Diamond Graduate-level physics, chemistry, and biology questions written by domain experts. | — | 90.9% | — |
Humanity's Last Exam Expert-written questions across hundreds of disciplines designed to resist saturation. | 64.4% | 42.6% | Claude Opus 5.5 (+51%) |
FrontierMath v2 (Tiers 1-3) Unpublished, research-level mathematics problems across Tiers 1-3. | 91.2% | 67.4% | Claude Opus 5.5 (+35%) |
Design Arena ELO Human-preference ELO across UI, 3D, data-visualization, and game-dev generations. | 1468 | 1362 | Claude Opus 5.5 (+8%) |
Claude Opus 5.5 leads across 6 evaluated benchmarks compared to 0 for DeepSeek V4.1 Flash 1017, showing notable advantages in Artificial Analysis Intelligence Index, Artificial Analysis Coding Agent Index v2.0, Terminal-Bench 4.0.
DeepSeek V4.1 Flash 1017 has the larger context capacity of 1.0M tokens (1,048,576 tokens), compared to 1M tokens for Claude Opus 5.5.
DeepSeek V4.1 Flash 1017 is more economical. Input tokens cost $Free (Open Weights)/M tokens compared to $4/M tokens for Claude Opus 5.5.
Claude Opus 5.5 is a proprietary cloud API. DeepSeek V4.1 Flash 1017 is an open-weights model.
Analyze 130+ models side-by-side using interactive radar charts, cost-efficiency quadrant plots, and live dataset filters on the full NeuBench index.
Open Interactive Comparator