DeepSeek V4 vs GPT-5.6
Pricing, benchmarks, and use case comparison
Quick take
- •DeepSeek V4 is meaningfully stronger at cost efficiency (88 vs 70 on our capability index).
- •GPT-5.6 is meaningfully stronger at multimodal (87 vs 10).
- •DeepSeek V4 is open-weights (free to self-host); GPT-5.6 is paid API only.
Specs comparison
| DeepSeek V4 | GPT-5.6 | |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Type | Open source | Closed source |
| Context window | ✓1M tokens | Not announced |
| Input / 1M tokens | ✓Free (self-host) | 5 |
| Output / 1M tokens | Free (self-host) | 30 |
| Release date | 2026-04 | 2026-06 |
Benchmarks
| Benchmark | DeepSeek V4 | GPT-5.6 |
|---|---|---|
| SWE-bench Verified | 80.6% | - |
| Math / STEM / Coding (open-model comparison) | Best among open models (per DeepSeek) | - |
| 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 DeepSeek V4 if...
- →You need a frontier-class open model you can self-host for data control
- →Your workload involves very long documents, codebases, or agent trajectories (up to 1M tokens)
- →You want top-tier agentic coding at a fraction of closed-model cost
- →You need to fine-tune or customize a strong base model
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