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 — Z.ai (Zhipu AI)
GLM-5.3-Flash is the first natively multimodal model in Z.ai's GLM-5 series, with 320B total and 18B activated parameters and a hybrid of linear and sparse attention. Its weights are released under the MIT licence.
Model B — ByteDance Seed
Seed2.1 Pro is the larger model of ByteDance Seed's Seed2.1 family, which ByteDance describes as agent-capable models for real-world productivity, aimed at stronger reasoning, agentic execution and complex workflows. It is available to Doubao and Volcano Engine users as Doubao-Seed-2.1-Pro.
| Property | GLM-5.3-Flash | Seed2.1 Pro |
|---|---|---|
| Released | Aug 26, 2026 | Jun 23, 2026 |
| Developer | Z.ai (Zhipu AI) | ByteDance Seed |
| Type | multimodal | multimodal |
| License | open-weight | proprietary |
| Context window | — | — |
| Parameters | 320B total, 18B activated | — |
| Developer status | — | — |
| Input $/M tokens | $0.15 | — |
| Output $/M tokens | $0.50 | — |
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=glm-5-3-flash&b=seed-2-1-pro. CORS is open. Citation guidance: /about/editorial-process.