Granite 4.1 8B vs GPT-5.6 Luna compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.
Prices & specs refreshed from live data · olud.ai
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
| Spec | Granite 4.1 8B | GPT-5.6 Luna |
|---|---|---|
| Maker | IBM | OpenAI |
| Type | Open-weight | Proprietary |
| Context window | 131K tokens | 1.1M tokens |
| Input price | $0.05/M · free self-host | $0.5/M |
| Output price | $0.1/M · free self-host | $3/M |
| Vision / multimodal | No | Yes |
| Tool / function calling | Yes | Yes |
| Self-hostable | Yes | No (API only) |
| License | Apache 2.0 | Proprietary |
| Capability | Granite 4.1 8B | GPT-5.6 Luna |
|---|---|---|
| Open weights (downloadable) | ✓ | ✗ |
| Self-hostable | ✓ | ✗ |
| Runs fully offline | ✓ | ✗ |
| Vision / multimodal | ✗ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✗ | ✓ |
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
| Criterion | Granite 4.1 8B | GPT-5.6 Luna |
|---|---|---|
| Cost-efficiency | 5.0 | 4.0 |
| Context window | 3.5 | 5.0 |
| Openness | 5.0 | 1.5 |
| Self-hosting | 5.0 | 1.0 |
| Multimodality | 3.5 | 5.0 |
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.
Granite 4.1 8B is a dense, decoder-only 8-billion-parameter language model from IBM, part of the Granite 4.1 family. It supports a 131K-token context window and is designed for enterprise tasks...
GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Granite 4.1 8B is open-weight and competitive on many tasks, but GPT-5.6 Luna may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.
Yes. Granite 4.1 8B has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-5.6 Luna is API-only and cannot be self-hosted.
Granite 4.1 8B costs $0.1/M output vs $3/M for GPT-5.6 Luna — roughly 30x cheaper via API, and free if you self-host.
Choose Granite 4.1 8B if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-5.6 Luna if you want frontier capability through a managed API with zero infrastructure to run.
Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.
Open the leaderboard →