# Solar Mini 4: AI model fact sheet

- **Provider:** upstage
- **Released:** 2026-09-23
- **Context window:** 524,288 tokens
- **API pricing:** $0.05 / 1M input, $0.20 / 1M output
- **OpenRouter ID:** upstage/solar-mini4
- **Capabilities:** conversation, reasoning, analysis, code-generation, tool-use

Upstage's compact mixture-of-experts model with 35 billion total parameters and 3 billion active parameters. It supports text generation, tool calling, and a 524,288-token context.

Source: real side-by-side outputs, pricing and specs at https://rival.tips/models/solar-mini4