GPT-5.6 Sol Paid vs 
Solar Pro 4 Paid
GPT-5.6 Sol vs Solar Pro 4 compared — price per token, context window, multimodality, openness and which to choose. Full 2026 breakdown.
GPT-5.6 Sol — full profile › · Solar Pro 4 — full profile ›
Prices & specs refreshed from live data · olud.ai
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
$10 /M outputManaged API (no infra to run)
$0.36 /M outputManaged API (no infra to run)
GPT-5.6 Sol vs Solar Pro 4 specs
| Spec | GPT-5.6 Sol | Solar Pro 4 | Winner |
|---|---|---|---|
| Maker | OpenAI | Upstage | – |
| Type | Proprietary | Proprietary | – |
| Context window | 1.1M tokens | 524K tokens | |
| Input price | $2/M | $0.09/M | |
| Output price | $10/M | $0.36/M | |
| Vision / multimodal | Yes | No | |
| Tool / function calling | Yes | Yes | = Tie |
| Self-hostable | No (API only) | No (API only) | – |
| License | Proprietary | Proprietary | – |
Price gap & when to choose each
Solar Pro 4 is ~28× cheaper than GPT-5.6 Sol on output tokens ($0.36 vs $10 per M tokens).
- You want frontier performance through a managed API
- You need the longer 1.1M context window
- You value reliability & ecosystem
- You don't want to manage infrastructure
- You want frontier performance through a managed API
- You want the lower output price
- You value reliability & ecosystem
- You don't want to manage infrastructure
Feature comparison
| Capability | GPT-5.6 Sol | Solar Pro 4 |
|---|---|---|
| Open weights (downloadable) | ✗ | ✗ |
| Self-hostable | ✗ | ✗ |
| Runs fully offline | ✗ | ✗ |
| Vision / multimodal | ✓ | ✗ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✓ | ✗ |
Benchmarks: GPT-5.6 Sol vs Solar Pro 4
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How GPT-5.6 Sol and Solar Pro 4 score
| Criterion | GPT-5.6 Sol | Solar Pro 4 |
|---|---|---|
| Cost-efficiency | 3.5 | 5.0 |
| Context window | 5.0 | 4.5 |
| Openness | 1.5 | 1.5 |
| Self-hosting | 1.0 | 1.0 |
| Multimodality | 5.0 | 3.5 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
What each model is
GPT-5.6 Sol Paid
GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks...
Solar Pro 4 Paid
Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in office productivity, document-intensive...
Frequently asked questions
GPT-5.6 Sol vs Solar Pro 4 — which is cheaper?
Solar Pro 4 is cheaper on output ($0.36/M vs $10/M).
Which has the larger context window?
GPT-5.6 Sol offers the larger context window (1.1M tokens).
GPT-5.6 Sol vs Solar Pro 4 — which should I pick in 2026?
Choose Solar Pro 4 for the lower output price ($0.36/M vs $10/M). Choose GPT-5.6 Sol if you need the larger 1.1M context window.
People also compare
Explore more open-source AI
Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.
Open the leaderboard →