Skip to content
ModelCap

Head-to-head comparison

Solar Open2 250B vs Solar Pro 4

Solar Open2 250B (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 August 2026

As of 17 August 2026, Solar Open2 250B holds the stronger ModelCap Index position (#47 vs #52).

Which should you choose?

Choose Solar Open2 250B if…

  • you want the stronger overall ModelCap Index position — #47 against #52 (51.4 vs 46.5 points).

Choose Solar Pro 4 if…

  • you want provider choice — 1 listed API providers against 0.
  • Artificial Analysis Intelligence Index is your yardstick — 41.6 against 37.4.
  • you want the more recently listed model — Solar Pro 4 was listed 10 August 2026, Solar Open2 250B 22 July 2026.

Solar Open2 250B vs Solar Pro 4: specs, pricing and context

Specification comparison of Solar Open2 250B and Solar Pro 4
FieldSolar Open2 250BUpstageSolar Pro 4Upstage
ModelCap Index position#47#52
Index score51.446.5
EvidenceMeasuredMeasured
Input price / 1M tokensUnlisted$0.03
Output price / 1M tokensUnlisted$0.12
Context window— tokens524K tokens
Max output tokens—131K
API providers listed01
Weight accessRestricted licenseAPI only
Input modalitiesTextText
First listed22 July 202610 August 2026
PublisherUpstageUpstage

Evidence: 1 public benchmark observation across 1 board · 4 public benchmark observations across 4 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Solar Open2 250B vs Solar Pro 4

Public benchmark boards where Solar Open2 250B or Solar Pro 4 has a published result
BoardSolar Open2 250BSolar Pro 4Leads
Arena codingArena (LMArena)—14501427–1473Only one result
LMArena AgentLMArena—-10.1%-12.3%–-7.9%Only one result
Artificial Analysis Intelligence IndexArtificial Analysis37.4intelligence-index41.6intelligence-indexSolar Pro 4

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 Open2 250B vs Solar Pro 4: common questions

Is Solar Open2 250B better than Solar Pro 4?

Solar Open2 250B ranks higher on the ModelCap Index as of 17 August 2026: #47 against #52. 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.

Is Solar Open2 250B cheaper than Solar Pro 4?

At least one of the two has no listed API price on ModelCap right now, so no price comparison is made.

Which has the bigger context window, Solar Open2 250B or Solar Pro 4?

Both publish a —-token context window.

Which is better for coding, Solar Open2 250B or Solar Pro 4?

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.

Are Solar Open2 250B and Solar Pro 4 open-weight models?

Solar Open2 250B: Restricted license. 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.

Where can I run Solar Open2 250B and Solar Pro 4?

ModelCap currently lists 0 API providers for Solar Open2 250B and 1 for Solar Pro 4, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Solar Open2 250B vs Solar Pro 4 comparison?

Every figure comes from the sealed ModelCap dataset published 17 August 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.

Explore further