DeepSeek V3 vs GPT-5.6 Sol
Pricing, benchmarks, and use case comparison
Quick take
- •DeepSeek V3 is meaningfully stronger at cost efficiency (92 vs 55 on our capability index).
- •GPT-5.6 Sol is meaningfully stronger at multimodal (88 vs 10).
- •DeepSeek V3 is open-weights (free to self-host); GPT-5.6 Sol is paid API only.
Specs comparison
| DeepSeek V3 | GPT-5.6 Sol | |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Type | Open source | Closed source |
| Context window | ✓128K tokens | Not announced |
| Input / 1M tokens | ✓Free (self-host) | $5.00 |
| Output / 1M tokens | Free (self-host) | $30.00 |
| Release date | 2024-12 | 2026-06 |
Benchmarks
| Benchmark | DeepSeek V3 | GPT-5.6 Sol |
|---|---|---|
| Pre-training scale | ~15T tokens | - |
| Terminal-Bench 2.1 | - | 88.8% |
| Terminal-Bench 2.1 (Ultra) | - | 91.9% |
| ExploitBench | - | competitive with Mythos Preview |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose DeepSeek V3 if...
- →You want a proven, stable open model with broad ecosystem support
- →You need to self-host or fine-tune without licensing friction
- →Cost is critical and you don't need V4's 1M context or top scores
- →You want reproducible open-weight behavior pinned to a known version
Choose GPT-5.6 Sol if...
- →You are an approved preview partner needing the most capable model for agentic software engineering
- →Complex multi-step tasks that benefit from subagent orchestration (Ultra) or maximum reasoning depth (max)
- →Frontier scientific research, professional knowledge work, or security-sensitive workloads