Loading benchmark catalogue
Compare performance benchmarks, coding intelligence, reasoning evaluations, context limits, and API economics between GPT-6 Astra (OpenAI) and Claude Opus 5.5 (Anthropic).
| Metric / Capability | GPT-6 Astra | Claude Opus 5.5 |
|---|---|---|
| Developer / Organization | OpenAI | Anthropic |
| Release Date | 2026-09-04 | 2026-09-22 |
| Deployment / Weights | Proprietary Cloud API | Proprietary Cloud API |
| Context Window | 1.1M tokens (1,050,000 tokens) | 1M tokens (1,000,000 tokens) |
| Input Pricing (/1M Tokens) | $10 | $4 |
| Output Pricing (/1M Tokens) | $50 | $20 |
| Benchmark / Domain | GPT-6 Astra | Claude Opus 5.5 | Advantage |
|---|---|---|---|
Artificial Analysis Intelligence Index Composite index aggregating 10+ evaluations of general reasoning and knowledge. | 52.7% | 57.6% | Claude Opus 5.5 (+9%) |
Artificial Analysis Coding Index Composite index of coding and software-engineering evaluations. | 76.9% | — | — |
Artificial Analysis Agentic Index Composite index of tool-use and long-horizon agentic tasks. | 51.0% | — | — |
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. | 54.7% | 61.7% | Claude Opus 5.5 (+13%) |
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. | 57.9% | 66.4% | Claude Opus 5.5 (+15%) |
ARC-AGI-2 Novel visual grid puzzles requiring abstract rule induction. | 95.0% | 91.7% | GPT-6 Astra (+4%) |
GPQA Diamond Graduate-level physics, chemistry, and biology questions written by domain experts. | 96.0% | — | — |
Humanity's Last Exam Expert-written questions across hundreds of disciplines designed to resist saturation. | — | 64.4% | — |
FrontierMath v2 (Tiers 1-3) Unpublished, research-level mathematics problems across Tiers 1-3. | 93.7% | 91.2% | GPT-6 Astra (+3%) |
Design Arena ELO Human-preference ELO across UI, 3D, data-visualization, and game-dev generations. | — | 1468 | — |
Claude Opus 5.5 outperforms GPT-6 Astra across 3 evaluated benchmarks compared to 2 for GPT-6 Astra, excelling in Artificial Analysis Intelligence Index, Artificial Analysis Coding Agent Index v2.0, Terminal-Bench 4.0.
GPT-6 Astra offers a larger context capacity of 1.1M tokens (1,050,000 tokens), compared to 1M tokens for Claude Opus 5.5.
Claude Opus 5.5 is more economical. Input tokens cost $4/M tokens compared to $10/M tokens for GPT-6 Astra.
GPT-6 Astra is a proprietary cloud API. Claude Opus 5.5 is a proprietary cloud API.
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