GPT-4o vs GPT-5.6
Pricing, benchmarks, and use case comparison
Quick take
- •GPT-4o is meaningfully stronger at speed (85 vs 72 on our capability index).
- •GPT-5.6 is meaningfully stronger at math (92 vs 62).
- •GPT-4o is 50% cheaper on input tokens, which compounds fast on high-volume or agentic workloads.
Specs comparison
| GPT-4o | GPT-5.6 | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓128,000 tokens (16,384 max output) | Not announced |
| Input / 1M tokens | ✓$2.50 | 5 |
| Output / 1M tokens | $10.00 | 30 |
| Release date | 2024-05 | 2026-06 |
Benchmarks
| Benchmark | GPT-4o | GPT-5.6 |
|---|---|---|
| MMLU | 88.7% | - |
| HumanEval | 90.2% | - |
| MATH | 76.6% | - |
| Terminal-Bench 2.1 (Sol) | - | 88.8% |
| Terminal-Bench 2.1 (Terra) | - | 82.5% |
| Terminal-Bench 2.1 (Luna) | - | 84.3% |
| Terminal-Bench 2.1 | - | 88.8 |
| ExploitBench | - | Competitive with Anthropic Mythos Preview |
| ExploitGym | - | Significant improvements |
| GeneBench v1 | - | Not announced |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose GPT-4o if...
- →Everyday assistant, drafting, summarization, and classification tasks
- →Latency- and cost-sensitive applications at scale
- →Multimodal tasks needing image understanding with fast responses
Choose GPT-5.6 if...
- →You want to standardize on one model generation but route requests across cost/quality tiers
- →You are an approved preview partner exploring the newest OpenAI capabilities
- →Workloads spanning agentic coding, knowledge work, and research where tier flexibility helps