GPT-5.6 Luna vs Granite 4 H Large
Side-by-side comparison of API pricing, specs, benchmarks, and capabilities
| Specification |
by OpenAI
|
by IBM
|
|---|---|---|
| Overview | ||
| Status | Current mid tier | Current mid tier Open weights |
| Released | Jul 9, 2026 | Oct 19, 2025 |
| Pricing per million tokens | ||
| Input | $0.200/Mtok | $0.300/Mtok |
| Output | $1.20/Mtok | $1.20/Mtok |
| Blended avg | $0.700/Mtok | $0.750/Mtok |
| Cached input | $0.020/Mtok | — |
| Specifications | ||
| Context window | 1M tokens | 128K tokens |
| Parameters | Proprietary | Proprietary |
| Speed (TPS) | — | — |
| Modalities | ||
| Input |
textimage
|
text
|
| Benchmarks sources: Vellum LLM Leaderboard / IBM model card | ||
| GPQA Diamond | 92.3 | 42 vendor |
| SWE-Bench Verified | 93 | 20 vendor |
| HumanEval | 93 | 75 vendor |
| Avg benchmark score | 90.7 | — |
| Perf / dollar | 25.9 | — |
| Terminal-Bench 2.1 | 84.3 | — |
| Humanity's Last Exam | — | 10 vendor |
| ARC-AGI 2 | — | 8 vendor |
| AIME 2025 | — | 35 vendor |
| MMMLU | — | 70 vendor |
| BFCL | — | 52 vendor |
| MATH 500 | — | 55 vendor |
| Independent composite scores each on its own scale — not part of the average above | ||
| AA Intelligence Index | 51.2 | — |
| AA Agentic Index | 45.6 | — |
| AA-Omniscience Index (−100–100) | -11.2 | — |
| GDPval-AA v2 | 1581.9 ELO | — |
| Providers | ||
| Available from |
OpenAI — $0.200/$1.20/Mtok
|
IBM — $0.300/$1.20/Mtok
|
Cost at scale
1M tokens · 50/50 input/output| Volume | GPT-5.6 Luna | Granite 4 H Large | Savings |
|---|---|---|---|
| 1M tokens | $0.7 | $0.75 | $0.05 (6.7%) |
| 10M tokens | $7 | $7.5 | $0.5 (6.7%) |
| 100M tokens | $70 | $75 | $5 (6.7%) |
| 1000M tokens | $700 | $750 | $50 (6.7%) |
When to pick which
distilled from the pricing and spec data above- cost dominates: $0.700/Mtok blended vs $0.750 — 6.7% less on the same 50/50 token mix
- your workload re-reads context (agents, RAG, long chats): cached input costs $0.020/Mtok — 90% off its list input price, a discount Granite 4 H Large doesn't offer
- you need the longer context: 1M tokens vs 128K (8.2×)
- you want open weights — self-host it, fine-tune it, or exit the API entirely; GPT-5.6 Luna is closed
Price movement
recorded changes since we began tracking each model · last checked Aug 1, 2026| Model | Changes | Latest move | Old → new $/M |
|---|---|---|---|
| GPT-5.6 Luna | 1 | price cut on Aug 1, 2026 | $1/$6 → $0.2/$1.2/Mtok |
| Granite 4 H Large | 0 | — no move | Stable since we began tracking — no change recorded |
The cheaper option here — GPT-5.6 Luna costs $0.700/Mtok blended on OpenAI.
Summary
GPT-5.6 Luna by OpenAI costs $0.200/Mtok input and $1.20/Mtok output, with a 1M-token context window. It supports text, image input.
Granite 4 H Large by IBM costs $0.300/Mtok input and $1.20/Mtok output, with a 128K-token context window. It supports text input.
On a blended cost basis, GPT-5.6 Luna is 6.7% cheaper than Granite 4 H Large. It also has a larger context window.
The two aren't directly comparable on average benchmark score: GPT-5.6 Luna has published per-benchmark results, while Granite 4 H Large does not yet.
Note: Pricing is per million tokens. Actual costs vary with usage patterns, prompt caching, and batch discounts. Always verify against official provider pricing pages.