Free {family} model via API
Upstage's Solar models are efficient LLMs with strong multilingual and document-understanding performance.
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The table refreshes every four hours from aggregator APIs. The same model at different providers is a separate endpoint with its own limits.
| # | Model ↕ | AA Index ↕ | GPQA ↕ | Context ↕ | Size ↕ | Free at ↕ | |
|---|---|---|---|---|---|---|---|
| 1 |  |
28.2 | 89% | 524K | Frontier |  UnoRouter |
|
| 2 |
Solar Mini4
Upstage · New
|
— | — | 524K | Small | UnoRouter |
Benchmarks: Artificial Analysis (September 24, 2026). A dash means the model is not on their leaderboard; we never estimate scores ourselves.
About Solar
Upstage's Solar models are efficient LLMs with strong multilingual and document-understanding performance.
FAQ
Which Solar models are free?
Currently 2 models are free: Solar Pro4, Solar Mini4.
Where can I get a free Solar API key?
Free Solar routes are available at: UnoRouter. Get a key in the provider's dashboard; links are on each model card.
Who develops Solar?
Upstage's Solar models are efficient LLMs with strong multilingual and document-understanding performance.