Solar Pro 4
#88 in Frontier LLMsUpstage · v4 · pro · since 10. August 2026 · 3× · last seen Aug 13, 2026
24
Momentum
Solar Pro 4 is Upstage's proprietary flagship language model, released in August 2026 as the successor to Solar Pro 3. It specializes in agentic workflows such as document processing, tool use, and office tasks, supporting a context window of roughly 512K–524K tokens. The model scored 42 on the Artificial Analysis Intelligence Index, a significant jump from its predecessor's 14, while pricing increased relative to Solar Pro 3.
Momentum trend
15.05.13.08.
Features
| Key Benchmark (%) | 42 points on Artificial Analysis Intelligence Index (vs. 14 for Solar Pro 3); Terminal-Bench v2.1: 57% |
| Context Window (Tokens) | 512K–524K tokens, up to 128K output tokens |
| License | Proprietary, no open weights (no Hugging Face release) |
| Multimodality | Text only (input and output), no image/audio modality |
| Platform | Upstage Console (first-party API), OpenRouter, Nous Research Hermes Agent |
| Price per 1M Tokens | $0.30 input / $1.20 output / $0.06 cache hit (standard); launch promo $0.03 / $0.12 through Sept 10, 2026 |
| Release Date | August 10, 2026 |