Overview
DeepSeek V4 Pro is the flagship of the V4 series, released in April 2026 alongside V4-Flash. It's a 1.6-trillion-parameter mixture-of-experts model with 49B parameters active per token and a 1-million-token context window, shipping under the permissive MIT licence with open weights on Hugging Face and ModelScope. DeepSeek describes V4-Pro-Max (its maximum reasoning effort mode) as the best open-source model available today, with top-tier coding and reasoning that significantly closes the gap to leading closed-source models.
V4 introduces a hybrid attention architecture combining Compressed Sparse Attention and Heavily Compressed Attention — in the 1M-token setting it needs only ~27% of V3.2's single-token inference FLOPs and ~10% of its KV cache on Pro. It adds manifold-constrained hyper-connections for stable signal propagation and uses the Muon optimizer. Pre-trained on more than 32T tokens, it posts standout scores on coding, math and agentic benchmarks, including a Codeforces rating of 3206.
Key capabilities
- 1.6T MoE with 49B active per token
- 1-million-token context window
- Best open-source model — leads coding and math benchmarks
- Hybrid attention — ~27% FLOPs / ~10% KV cache vs V3.2
At a glance
GPQA Diamond
90.1% (Pro Max)
LiveCodeBench
93.5% (Pro Max)
SWE Verified
80.6% (Pro Max)
Codeforces
3206 rating
Pricing: Low open-weight pricing — MIT-licensed and self-hostable.
Pros & cons
What we like
- Best-in-class open-source reasoning and coding
- Efficient hybrid attention at 1M context
- Open MIT weights, fully self-hostable
- Three reasoning modes (non-think, high, max)
Trade-offs
- Heavyweight to self-host at full 1.6T scale
- FP4+FP8 mixed precision needs compatible tooling
- Still trails the absolute top closed models on some agentic tasks
The verdict
DeepSeek V4 Pro is the open-weight model to beat in 2026 — frontier-adjacent reasoning and coding under a permissive MIT licence, with remarkable long-context efficiency. For teams that want the strongest self-hostable model available today, it's the leading choice; pair it with V4-Flash for cheaper, high-volume steps.
Best for: Frontier-adjacent open-weight reasoning, coding and self-hosting.
Frequently asked questions
What's the difference between V4 Pro and V4-Flash?
V4 Pro is the flagship (1.6T total / 49B active); V4-Flash is the efficient variant (284B total / 13B active) for cheaper, high-volume deployment. Both share the V4 architecture, 1M context and three reasoning modes — Flash trails on pure knowledge and the hardest agentic tasks but approaches Pro quality with a larger thinking budget.
What is V4-Pro-Max?
It's the maximum reasoning effort mode of V4 Pro, where DeepSeek says the model firmly establishes itself as the best open-source model available today — top-tier on coding benchmarks and significantly closer to closed-source frontier models on reasoning and agentic tasks.
