Head-to-head comparison
solar pro preview instruct (Upstage) and Solar Pro 4 (Upstage) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.
Snapshot as of 17 September 2026
As of 17 September 2026, Solar Pro 4 holds the stronger ModelCap Index position (#104 vs #169); and solar pro preview instruct ships open weights.
Evidence: publisher-corpus-prior over 197 held-out anchors (25%); launch card against 3 resolved peers on 4 rows (75%); exceeds every named peer on 1 of 4 rows; optimism haircut 0 from cross-lab-probe; shrunk 5.4 up toward the measured corpus · 3 public benchmark observations across 3 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.
Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.
Solar Pro 4 ranks higher on the ModelCap Index as of 17 September 2026: #104 against #169. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.
At least one of the two has no listed API price on ModelCap right now, so no price comparison is made.
Both publish a —-token context window.
The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.
solar pro preview instruct: Open weights. Solar Pro 4: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.
ModelCap currently lists 0 API providers for solar pro preview instruct and 1 for Solar Pro 4, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
Every figure comes from the sealed ModelCap dataset published 17 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.