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DeepSeek V4 Flash 0731: Benchmarks, Features, and Inference Speed

DeepSeek V4 Flash 0731: post-training benchmarks across Terminal-Bench (82.7%) and DeepSWE (54.4%), 1M context efficiency, and $0.14/$0.28 token economics.

Lucky Yaduvanshi
Lucky Yaduvanshi
Founder & AI Lead
Aug 10, 2026•Updated Sep 24, 2026•4 min read
Independent technical benchmark • Primary data & verified methodology cited below
DeepSeek V4 Flash 0731 Architecture and Benchmark Performance Overview

DeepSeek V4 Flash 0731 represents a milestone post-training upgrade to DeepSeek’s high-efficiency V4 Flash foundation model. Detailed in DeepSeek’s research paper (DeepSeek-V4: Towards Highly Efficient Million-Token Context Intelligence, arXiv:2606.19348), this release retains the sparse 284-billion-parameter Mixture-of-Experts (MoE) architecture with 13 billion active parameters per token, while dramatically enhancing agentic execution, terminal commands, and software engineering reasoning.

The update combines frontier-grade tool calling with unmatched token economics: $0.14 per million input tokens, $0.28 per million output tokens, and an ultra-low $0.0028 per million cached input tokens. Explore where DeepSeek models rank on our AI Model Leaderboard and run head-to-head tests in our Compare Arena.

DeepSeek V4 Flash 0731 at a Glance

Specification DeepSeek V4 Flash 0731 Specification
Release Date July 31, 2026
Architecture Sparse Mixture-of-Experts (MoE)
Technical Research Paper arXiv:2606.19348
Total Backbone Parameters 284 Billion
Active Parameters per Token 13 Billion (4.6% activation sparsity)
Context Window 1,048,576 Tokens (1M Standard)
Maximum API Output 384,000 Tokens
Input Price (Cache Miss) $0.14 per 1M tokens
Input Price (Cache Hit) $0.0028 per 1M tokens (98% discount)
Output Price $0.28 per 1M tokens
Execution Modes Dual: Thinking (Reasoning) + Non-Thinking (Speed)
Licensing Permissive MIT License (Hugging Face)

Architectural Innovations: Ultra-High Context Efficiency

DeepSeek’s technical report details several foundational engineering upgrades powering the V4 model family:

  1. Hybrid Attention Architecture (CSA + HCA + DSA): Combines Compressed Sparse Attention (CSA) and Heavily Compressed Attention (HCA) alongside DeepSeek Sparse Attention (DSA). This reduces KV-cache memory demands across 1,000,000 tokens by 90% compared to traditional Multi-Head Attention.
  2. Manifold-Constrained Hyper-Connections (mHC): Replaces standard residual connections with manifold-constrained paths, improving gradient stability across deep MoE layers.
  3. Inference Compute Savings: In 1M-token context environments, DeepSeek V4 requires only 27% of the single-token inference FLOPs of previous-generation architectures.

Benchmark Comparison: Calculated Deltas from Preview to 0731

The defining achievement of the 0731 build is its specialized agentic post-training curriculum:

Benchmark Evaluation V4 Flash Preview V4 Flash 0731 Absolute Delta Relative Improvement
DeepSWE v1.1 7.3% 54.4% +47.1 pts +645.2% improvement
Terminal-Bench 2.1 61.8% 82.7% +20.9 pts +33.8% improvement
CyberGym Security 38.7% 76.7% +38.0 pts +98.2% improvement
Toolathlon-Verified 49.7% 70.3% +20.6 pts +41.4% improvement
DSBench-FullStack 37.0% 68.7% +31.7 pts +85.7% improvement
NL2Repo Repository Synthesis 39.4% 54.2% +14.8 pts +37.6% improvement
AutomationBench Public 10.8% 25.1% +14.3 pts +132.4% improvement

Methodological Note: Scores represent vendor-verified evaluations. Learn more about evaluation standards in our SWE-bench Verified Explainer.

Key Benchmark Takeaways:

  • Transformative SWE Gains: Jumping from 7.3% to 54.4% on DeepSWE indicates that post-training reinforcement learning on execution environments can elevate a lightweight model into a viable autonomous coding engine.
  • Terminal Execution Parity: At 82.7% on Terminal-Bench 2.1, Flash-0731 operates within striking distance of Claude Opus 4.8 (85.0%) at roughly 1/50th of the operational cost.

Prompt Caching & Monthly Workload Economics

With cached input billed at $0.0028 per million tokens, developers maintaining persistent context in tools like DeepSeek Harness or Claude Code realize dramatic savings:

Monthly Developer Workload Cache-Miss Cost Cache-Hit Cost (90% Hit Rate) Total Monthly Expense
10M Input + 2M Output $1.40 $0.20 $0.76 / mo
100M Input + 20M Output $14.00 $1.96 $7.56 / mo
1B Input + 200M Output $140.00 $19.60 $75.60 / mo

Final Verdict

DeepSeek V4 Flash 0731 is the gold standard for high-efficiency agentic inference in 2026.

By packaging 82.7% Terminal-Bench capability, 1M context length, open MIT weights, and $0.14 / $0.28 token pricing, DeepSeek enables developers to run high-volume autonomous software engineering pipelines without unsustainable cloud bills.

Explore comparative rankings in our AI Model Leaderboard and review our DeepSeek V4 Flash vs GPT-5.6 Luna Comparison.

Sources, Disclosures & Primary Benchmark Data

Benchmark and pricing data is aggregated from OpenRouter, Artificial Analysis, and models.dev, then scored with the published RankLLMs Index. These are the primary sources behind the numbers in this article.

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Lucky Yaduvanshi

Lucky Yaduvanshi(luckyyaduvanshi.in →)

Founder of RankLLMs • AI Researcher & Software Engineer focusing on LLM benchmarking, DevOps, and autonomous coding agents.

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