Solar Mini 4
Fast and lightToolsUpstage · Released September 2026
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 part of Upstage's Solar line, compact models tuned for reasoning and document understanding, where Pro leads on capability and Mini trades size for cost.
Facts and pricing
- Provider
- Upstage
- Context window
- 524K tokens
- Input price
- 0.60 credits / 1M tokens ($0.050 raw)
- Output price
- 2.4 credits / 1M tokens ($0.20 raw)
- Vision (image input)
- No
- Tool calling
- Yes
- Extended reasoning
- No
Credits are what Zeplik bills: 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin. Raw prices shown per 1M tokens.
Try Solar Mini 4 now
What Solar Mini 4 is best for
- High-volume everyday tasks where speed and cost matter: summaries, drafts, quick questions
- Very long documents and codebases: a 524K-token window fits entire books or repositories in one conversation
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Example prompts
Prompts that suit a fast and light model like Solar Mini 4:
- Summarize this article in five bullet points
- Rewrite this email to be shorter and friendlier
- Give me ten name ideas for a hiking newsletter
- Translate this paragraph to Spanish and keep the tone
Upstage family
| Model | Context | Input cr/M | Output cr/M | Released |
|---|---|---|---|---|
| Solar Mini 4 | 524K | 0.60 | 2.4 | September 2026 |
| Solar Pro 4 | 524K | 1.1 | 4.3 | August 2026 |
| Solar Pro 3 | 131K | 1.8 | 7.2 | January 2026 |
Frequently asked questions
- What is Solar Mini 4?
- Solar Mini 4 is an AI model by Upstage. 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.
- How much does Solar Mini 4 cost on Zeplik?
- Input tokens cost 0.60 credits per million and output tokens 2.4 credits per million (1 credit = $0.10; the raw provider rates are $0.050 and $0.20 per million). New accounts start with free credits.
- How long can a conversation with Solar Mini 4 be?
- Solar Mini 4 has a 524K-token context window (524,288 tokens), which covers the conversation plus any documents you attach.
- Does Solar Mini 4 support images and tools?
- Solar Mini 4 is text-only and supports tool calling.
Related models
Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window.
Solar Pro 3 is Upstage's powerful Mixture-of-Experts (MoE) language model. With 102B total parameters and 12B active parameters per forward pass, it delivers exceptional performance while maintaining computational efficiency.
Claude Haiku 5.5 is Anthropic's small, fast model for high-volume, cost-sensitive work such as summarization, subagents, and browser use.
Nano Banana 2.1 (Gemini Nano Banana 2.1) is Google's image generation and editing model on the Flash tier, succeeding Nano Banana 2 and Nano Banana Pro.
Mistral Large 4 is a frontier multimodal (text and image input) model from Mistral AI built for reasoning, coding, and agentic workloads.
Ling 3.1 Flash is a hybrid reasoning mixture-of-experts model from inclusionAI, with 25B active parameters out of 560B total.
More you can do with Solar Mini 4
- 467 AI skillsReady-to-run expert methods for writing, data, code and more, each running on Solar Mini 4 or any model you pick.
- 997 integrationsConnect Gmail, Slack, GitHub, Notion and hundreds more so the assistant can work in your apps.
- Simple pricingPlus, Pro and Max plans with a monthly credit allowance that works across every model.