Solar Pro 4
Upstage's flagship model, specialized for agentic use.
- Capability
- —No ECI score yet
- Input
- $0.30per 1M tokens
- Output
- $1.20per 1M tokens
- Context
- 524K131K max output
What it costs
- Input
- $0.30per million tokens
- Output
- $1.20per million tokens
- Cached input
- $0.06per million tokens
- Blended (3:1)
- $0.525cheaper than 59% of priced models
Typical monthly bills
| Monthly usage | Estimated cost |
|---|---|
| Side project2M input + 0.5M output tokens | $1.20 |
| Team assistant25M input + 5M output tokens | $13.50 |
| Production app250M input + 50M output tokens | $135.00 |
Official Upstage API price, as listed on models.dev.
Independent benchmarks
Epoch AI has not published a Capabilities Index score for Solar Pro 4 yet.
The details
- Lab
- Upstage
- Released
- Aug 6, 2026
- Knowledge cutoff
- Feb 2026
- Context window
- 524,288 tokens
- Max output
- 131,072 tokens
- Inputs
- Text
- Output
- Text
- Reasoning
- Adjustable effort minimal · low · medium · high · xhigh · max
- Tool calling
- Yes
- Structured output
- Yes
- Weights
- Proprietary
- API model ID
solar-pro4on Upstage- Availability
- 3 API providerslisted on models.dev
More from Upstage
About Solar Pro 4
How much does Solar Pro 4 cost?
Solar Pro 4 costs $0.30 input / $1.20 output per million tokens (official Upstage API price). Cached input is $0.06 per million tokens. At a 3:1 input-to-output mix that is $0.525 per million tokens, cheaper than 59% of the 360 priced models we track.
What is the context window of Solar Pro 4?
Solar Pro 4 accepts up to 524,288 tokens per request and can write up to 131,072 tokens in one response.
How good is Solar Pro 4?
Epoch AI has not published a Capabilities Index score for Solar Pro 4 yet.
Is Solar Pro 4 open source?
No. Solar Pro 4 is proprietary; you use it through Upstage’s API or partner platforms.
What inputs does Solar Pro 4 support?
Solar Pro 4 accepts text and replies in text. It is a reasoning model with minimal, low, medium, high, xhigh and max effort settings, supports tool calling and can return structured JSON output.
When was Solar Pro 4 released?
Upstage released Solar Pro 4 on Aug 6, 2026. Its training data runs to Feb 2026.
What are the best alternatives to Solar Pro 4?
The closest current models from other labs on capability, price and release date are Muse Glimmer 30B (Meta, $0.30 / $1.20), Ornith 1.5 35B A3B (DeepReinforce, $0.20 / $1.70), MiMo-V2.6-Pro (Xiaomi, $0.435 / $0.87) and Toast 1 (Mixedbread, $0.30 / $0.72).