DeepSeek V3.1 vs DeepSeek V4 Flash
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for DeepSeek V3.1 and DeepSeek V4 Flash.
DeepSeek V3.1
DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates. It extends the DeepSeek-V3 base with a two-phase long-context...
DeepSeek V4 Flash
DeepSeek V4 Flash is an efficiency-optimized Mixture-of-Experts model from DeepSeek with 284B total parameters and 13B activated parameters, supporting a 1M-token context window. It is designed for fast inference and...
Technical Specifications
| Specification | DeepSeek V3.1 | DeepSeek V4 Flash |
|---|---|---|
| Provider | DeepSeek | DeepSeek |
| Context Window | 163,840 tokens | 1,048,576 tokens |
| Agent Suitability | N/A | 86/100 |
| Time to First Token (TTFT) | N/A | 120 ms |
| Deployment Model | self hostable | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-08-21 | 2026-04-24 |
API Pricing Comparison
Input Price per Million Tokens
DeepSeek V3.1
$0.21
DeepSeek V4 Flash
$0.09
Output Price per Million Tokens
DeepSeek V3.1
$0.79
DeepSeek V4 Flash
$0.18
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
DeepSeek V3.1 Quirks & Gotchas
No developer gotchas reported.
DeepSeek V4 Flash Quirks & Gotchas
- ▸Best cost-per-token ratio of any hosted API — ideal for high-throughput pipelines
- ▸Lower agentic performance vs V4 Pro — route complex tool calls accordingly