AI Model Comparison
Side-by-side comparison of pricing, context window, benchmarks, capabilities, and license. Every figure comes from the developer's own pages, last checked on ; each model's page lists its sources. A figure we could not source shows as a dash.
Model A — Anthropic
Claude Opus 5.5 is Anthropic's model for long-running agentic coding and knowledge work, released on September 22, 2026, and the model Anthropic recommends starting with for most workloads. It takes text and image input, returns text, and its thinking cannot be disabled.
Model B — OpenAI
GPT-6 Astra is a reasoning model from OpenAI, released in the API on September 3, 2026, which OpenAI describes as its most capable API model for complex reasoning, coding, computer use, research and document creation. It takes text and image input, returns text, and has an April 30, 2026 knowledge cutoff.
| Property | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|
| Released | Sep 22, 2026 | Sep 3, 2026 |
| Developer | Anthropic | OpenAI |
| Type | reasoning | reasoning |
| License | proprietary | proprietary |
| Context window | — | 1,050,000 |
| Parameters | — | — |
| Developer status | — | — |
| Input $/M tokens | $4.00 | $10.00 |
| Output $/M tokens | $20.00 | $50.00 |
Bold green values indicate the winner on that dimension where comparison is meaningful (lower price wins; bigger context wins; more open license wins; newer date wins). Prices are the ones each developer lists today; a model it no longer prices has none.
Programmatic access available at /api/ai/compare?a=claude-opus-5-5&b=gpt-6-astra. CORS is open. Citation guidance: /about/editorial-process.