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 — DeepSeek
DeepSeek-V4.1-Flash is a 552B-parameter Mixture-of-Experts model with native visual understanding, which DeepSeek calls the smallest model in its new architecture family. It is served on the DeepSeek API under the model name deepseek-flash, with open weights under the MIT License.
| Property | Claude Sonnet 5.5 | DeepSeek-V4.1-Flash |
|---|---|---|
| Released | Sep 28, 2026 | Sep 10, 2026 |
| Developer | Anthropic | DeepSeek |
| Type | multimodal | multimodal |
| License | proprietary | open-weight |
| Context window | — | 1,000,000 |
| Parameters | — | 552B total (MoE); 8B active parameters for input (prefill), 16B for output (decode) |
| Developer status | — | — |
| Input $/M tokens | $2.00 | $0.30 |
| Output $/M tokens | $10.00 | $1.20 |
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=deepseek-v4-1-flash. CORS is open. Citation guidance: /about/editorial-process.