Solar Mini 4
Summary
Solar Mini 4 is a language model from Upstage, released on 23 Sept 2026. It accepts text and generates text, with a 524K-token context window and up to 131K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $0.05 per million input tokens and $0.20 per million output tokens (OpenRouter), across 1 provider we track.
Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524K context window. It is built for agentic use cases where response...
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | Upstage |
|---|---|
| Release date | 23 Sept 2026 [OpenRouter] |
| Status | Generally available |
| Context window | 524K (524,288 tokens) [OpenRouter] |
| Max output | 131K tokens [OpenRouter] |
| Input | Text [OpenRouter] |
| Output | Text [OpenRouter] |
| Reasoning mode | Yes [OpenRouter] |
| Tool calling | Yes [OpenRouter] |
| Structured output | Yes [OpenRouter] |
Solar Mini 4 API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| OpenRouter upstage/solar-mini4 | $0.05 | $0.20 | $0.005 | 524K | OpenRouter, 4 Oct 2026 |
Frequently asked questions
What is the context window of Solar Mini 4?
Solar Mini 4 has a context window of 524,288 tokens (524K) and can generate up to 131,072 tokens in a single response, according to OpenRouter.
How much does the Solar Mini 4 API cost?
Solar Mini 4 is listed from $0.05 per million input tokens and $0.20 per million output tokens (OpenRouter). Prices last verified 4 Oct 2026.
When was Solar Mini 4 released?
Upstage released Solar Mini 4 on 23 Sept 2026, according to OpenRouter.
Change history
No changes detected since we started tracking this model. We re-check every source daily.