---
id: "upstage/solar-mini4"
also: ["upstage/solar-mini4-20260922"]
card_usd_per_m: "0.05 in, 0.2 out, at upstage"
cheapest_list_usd_per_m: "0.05 in, 0.2 out, at upstage on openrouter"
cheapest_effective_usd_per_m: "0.0294 in, 0.3642 out, at upstage/zdr on openrouter"
context: 524288
max_output: 131072
input: ["text"]
output: ["text"]
released: "2026-09-23"
reasoning: ["max", "xhigh", "high", "medium", "low", "minimal", "none"]
api: ["/api/v1/chat/completions", "/api/v1/completions", "/api/v1/messages", "/api/v1/responses"]
params: ["frequency_penalty", "include_reasoning", "max_tokens", "parallel_tool_calls", "presence_penalty", "reasoning", "reasoning_effort", "response_format", "structured_outputs", "temperature", "tool_choice", "tools", "top_p"]
endpoints: 2
gateways: "openrouter (2)"
no_training: 2
trains: 0
retains_prompts: 1
---
# Upstage: Solar Mini 4

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...