Compare / head-to-head
Claude Opus 5.5vs
GPT-6 Astra
GPT-6 Astra leads 2 of 2 shared benchmarks. Claude Opus 5.5 is 2.5x cheaper per token. GPT-6 Astra has the larger context window (1.1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0 – 2
GPT-6 Astra leads
Cheaper per token
Claude Opus 5.5
2.5x cheaper, input + output
Larger context
GPT-6 Astra
1.1M tokens
Providers
2 providers
Anthropic · OpenAI
Claude Opus 5.5
Anthropic · released 2026-09-22
textvision
GPT-6 Astra
OpenAI · released 2026-09-03
textvision
Quality
Benchmark matrix
2 shared · 7 only Claude Opus 5.5 · 5 only GPT-6 Astra| Benchmark | Claude Opus 5.5 | GPT-6 Astra | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 2 | ||||
| AutomationBench 1.0.6 | 40% ↗ | 41.4% ↗ | -1.4 pt | GPT-6 Astra |
| Terminal-Bench Science 0.1 | 58.7% ↗ | 64.6% ↗ | -5.9 pt | GPT-6 Astra |
| Only Claude Opus 5.5 reports · 7 | ||||
| Chartography (with tools) | 89% ↗ | not reported | — | — |
| CursorBench 4.0 | 57.8% ↗ | not reported | — | — |
| FrontierCode v1.1 (Main) | 54.4% ↗ | not reported | — | — |
| GDPval-AA v2.1 | 1846 ↗ | not reported | — | — |
| Humanity's Last Exam (with tools) | 67.7% ↗ | not reported | — | — |
| OSWorld 2.0 (partial) | 81.8% ↗ | not reported | — | — |
| Terminal-Bench 4.0 | 66.4% ↗ | not reported | — | — |
| Only GPT-6 Astra reports · 5 | ||||
| GPQA Diamond | not reported | 96% ↗ | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | not reported | 97.6% ↗epoch | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | not reported | 93.7% ↗epoch | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | not reported | 100% ↗epoch | — | — |
| SimpleQA Verified | not reported | 75.6% ↗epoch | — | — |
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 Opus 5.5 minus GPT-6 Astra 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 Opus 5.5 | GPT-6 Astra | Edge |
|---|---|---|---|
| Context window | 1M tokens | 1.1M tokens | GPT-6 Astra |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $4 ↗ | $10 ↗ | Claude Opus 5.5 |
| Output price / 1M | $20 ↗ | $50 ↗ | Claude Opus 5.5 |
| Cached input / 1M | $0.2 ↗ | $1 ↗ | Claude Opus 5.5 |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $24 | $60 | Claude Opus 5.5 |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-09-22 | 2026-09-03 | — |
| Cited benchmark scores | 9 | 8 | — |
Reliability
Provider status
Live from /statusMore matchups
Claude Opus 5.5 vs …
Models sharing the most benchmarksMore matchups
GPT-6 Astra vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Opus 5.5 and GPT-6 Astra on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.