GPT-5.4 mini vs GPT-5.1 Codex Max
30-second takeaway
- GPT-5.4 mini has the cheaper input: $0.75 vs $1.25 (per 1M tokens, 40% less)
- Same context window (400K tokens)
| GPT-5.4 mini OpenAI | GPT-5.1 Codex Max Abacus | |
|---|---|---|
| Input | $0.75 | $1.25 |
| Output | $4.5 | $10 |
| Context | 400K | 400K |
More specs (max output / capabilities)
| max output | 128,000 | 128,000 |
| Reasoning | ✓ Yes | ✓ Yes |
| Tool calls | ✓ Yes | ✓ Yes |
| Open weights | — No | — No |
Prices are official/data-source rates (per 1M tokens), not what relays actually charge — relay prices vary with discounts and group multipliers. See methodology.