IBM Granite 4.0 vs Codex (OpenAI)
Which one should you pick? Here's the full breakdown.
IBM Granite 4.0
IBM's enterprise-focused open-weight family -- Granite 4.0 hybrid Mamba-2 + transformer architecture (70-80% memory reduction vs pure transformer), 3B to 32B sizes, Apache 2.0. First open model family to secure ISO 42001 certification. Nano 350M runs on CPU with 8-16GB RAM. 3B Vision variant landed 2026-04-01
Codex (OpenAI)
OpenAI's cloud-based coding agent -- runs parallel tasks, proposes PRs, and lives inside ChatGPT
Powered by GPT-5.3-Codex / GPT-5.4
| Category | IBM Granite 4.0 | Codex (OpenAI) |
|---|---|---|
| Ease of Use | 7.0 | 8.0 |
| Output Quality | 8.0 | 8.0 |
| Value | 9.5 | 8.0 |
| Features | 8.5 | 9.0 |
| Overall | 8.2 | 8.3 |
Pricing Comparison
| Feature | IBM Granite 4.0 | Codex (OpenAI) |
|---|---|---|
| Free Tier | Yes | Yes |
| Starting Price | $0 | $0 |
Benchmark Head-to-Head
GPT-5.3-Codex benchmarks — IBM Granite 4.0 has no published benchmarks
| Benchmark | Description | Score |
|---|---|---|
| SWE-bench | Real GitHub issue fixing | 72% |
| HumanEval | Python code generation | 95% |
Which Should You Pick?
Pick IBM Granite 4.0 if...
- ✓Better value for money (9.5/10)
Regulated-industry enterprises (healthcare, finance, government) who need Apache 2.0 open-weight models with ISO 42001 certification. Also ideal for edge deployments where Granite Nano (350M / 1.5B) is one of the few open models that runs realistically on CPU. And for any Mamba-hybrid research or low-memory production use where the 70-80% memory reduction actually changes the economics.
Visit IBM Granite 4.0Pick Codex (OpenAI) if...
- ✓Easier to use (8 vs 7)
Developers already paying for ChatGPT Plus who want a coding agent at no extra cost. Especially good for parallel task execution -- assign multiple bug fixes or feature branches and let Codex work them simultaneously.
Visit Codex (OpenAI)Our Verdict
IBM Granite 4.0 and Codex (OpenAI) are extremely close overall. Your choice comes down to specific needs -- IBM Granite 4.0 is better for regulated-industry enterprises (healthcare, finance, government) who need apache 2, while Codex (OpenAI) works best for developers already paying for chatgpt plus who want a coding agent at no extra cost.