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 Sonnet 5.5 is a model from Anthropic, released on September 28, 2026, which Anthropic describes as its best combination of speed and intelligence. It takes text and image input, returns text, and supports adaptive thinking; Anthropic names it the replacement for Claude Sonnet 4.5.
Model B — Meta
Muse Spark Open is an open-weight mixture-of-experts model from Meta, released on October 15, 2026, with 816B total and 42B active parameters. It takes text, image, video and audio input and returns text. Meta's own Model API does not serve it: it is self-hosted or run through hosted providers.
| Property | Claude Sonnet 5.5 | Muse Spark Open |
|---|---|---|
| Released | Sep 28, 2026 | Oct 15, 2026 |
| Developer | Anthropic | Meta |
| Type | multimodal | multimodal |
| License | proprietary | open-weight |
| Context window | — | 1,048,576 |
| Parameters | — | 816B total, 42B active (mixture of experts) |
| Developer status | — | — |
| Input $/M tokens | $2.00 | — |
| Output $/M tokens | $10.00 | — |
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.
No exclusive capabilities
Programmatic access available at /api/ai/compare?a=claude-sonnet-5-5&b=muse-spark-open. CORS is open. Citation guidance: /about/editorial-process.