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DeepSeek: DeepSeek V4.1 Flash 1017

deepseek/deepseek-v4.1-flash-1017

Model weights

DeepSeek V4.1 Flash 1017 is the October 17, 2026 snapshot of DeepSeek V4.1 Flash, served by DeepSeek under the deepseek-flash API model name. V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder (CED) architecture. It activates 8B parameters on input and 16B on output from a 552B-parameter backbone, an asymmetric split that keeps per-token compute low relative to the model's total size. Image understanding is native to the architecture, with visual and text embeddings trained jointly from the start of pre-training rather than added afterward as in the earlier experimental V4 Flash Vision Exp.

It is suited for coding, terminal, and computer-use agents, along with long-horizon tasks that must run to completion across many steps and long-context analysis. Compressed KV caching cuts cache memory to roughly a quarter of the previous Flash generation, significantly reducing costs on agentic workloads. DeepSeek positions it as the cost-efficient tier of the V4.1 family and reports that it exceeds V4 Pro on performance, speed, and task completion time.

Modalities
In / out price
$0.038 / $0.50per 1M
Context
1.0M
Released
Oct 17, 2026

Providers

Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).

Pricing

The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.

Weighted average

Input
$0.01453/M tokens
Output
$0.66/M tokens
Price history
No effective price data for this selection

Performance

Throughput is how fast the model writes (tokens per second — higher is better). Latency is total round-trip time (lower is better). TTFT is time-to-first-token — how long before you see anything appear (lower is better).

Throughput
400tok/s

P50, best across providers

Latency
0.32s

P50, best provider

AutoExacto benchmarks
GPQA DiamondTAU-BenchTenstorrent92.8%--PrimaLabs91.7%--Baseten (Fast)90.6%--AtlasCloud90.4%77.8%CoreWeave91.5%76.3%Baseten89.8%76.5%
+37 more providers

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Uptime (3d)The model was reachable. Request routed to a provider.
100.00%
Availability (3d)The model returned inference from any provider. Errors and empty responses count against it.
99.89%

Availability over the last 3 days

Last 72 hours
Availability 99.89%
3 Days Ago2 Days AgoYesterdayNow

Availability over the last 24 hours

OpenRouter Availability
99.86%
Without Routing
95.81%

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.

Benchmarks

Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.

Benchmark score summary for DeepSeek: DeepSeek V4.1 Flash 1017 (Artificial Analysis, Design Arena and Vals AI)
SourceBenchmarkScore
Artificial AnalysisDeepSeek V4.1 Flash 1017 (High) Intelligence Index28.6
Artificial AnalysisDeepSeek V4.1 Flash 1017 (High) Terminal-Bench 4.028.8%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (High) AA-Omniscience Accuracy38.9%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (High) AA-Omniscience Non-Hallucination Rate38.8%
Artificial AnalysisDeepSeek V4.1 Flash (Max) HLE39.2%
Artificial AnalysisDeepSeek V4.1 Flash (Max) AA-LCR84.0%
Artificial AnalysisDeepSeek V4.1 Flash (Max) GDPval-AA55.0%
Artificial AnalysisDeepSeek V4.1 Flash (Max) CritPt14.3%
Artificial AnalysisDeepSeek V4.1 Flash (Max) SciCode51.9%
Artificial AnalysisDeepSeek V4.1 Flash (Max) Terminal-Bench 4.026.8%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) Intelligence Index18.5
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) HLE11.5%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) AA-LCR57.3%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) CritPt0.3%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) SciCode38.5%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) Terminal-Bench 4.09.1%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) AA-Omniscience Accuracy21.9%
Artificial AnalysisDeepSeek V4.1 Flash 1017 (Non-reasoning) AA-Omniscience Non-Hallucination Rate74.7%
Design ArenaDeepSeek-V4.1-Flash (1017) Agents Arena Spreadsheet Elo1286
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena 3D Elo1341
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena Asciiart Elo1232
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena Code Categories Elo1286
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena Data Visualization Elo1260
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena Game Development Elo1250
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena SVG Elo1244
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena UI Component Elo1286
Design ArenaDeepSeek-V4.1-Flash (1017) Models Arena Website Elo1294
Vals AIDeepSeek V4.1 Flash 1017 Access to Justice Benchmark73.1%
Vals AIDeepSeek V4.1 Flash 1017 Code Migration v1.167.5%
Vals AIDeepSeek V4.1 Flash 1017 CyberOffense54.8%
Vals AIDeepSeek V4.1 Flash 1017 EMB v1.169.2%
Vals AIDeepSeek V4.1 Flash 1017 Finance Agent v2.162.9%
Vals AIDeepSeek V4.1 Flash 1017 Vals Finance Index60.9%
Vals AIDeepSeek V4.1 Flash 1017 HLAB-Vals-1.114.2%
Vals AIDeepSeek V4.1 Flash 1017 Vals Legal Index71.9%
Vals AIDeepSeek V4.1 Flash 1017 Legal Research Bench45.2%
Vals AIDeepSeek V4.1 Flash 1017 Tax Agent Bench44.4%
Vals AIDeepSeek V4.1 Flash 1017 Terminal-Bench 4.031.8%
Vals AIDeepSeek V4.1 Flash 1017 Vals Index61.3%
Vals AIDeepSeek V4.1 Flash 1017 Vibe Code Bench v1.187.7%

Apps

Public apps that send the most traffic to this model. Good signal for what real production workloads look like — and a hint at which use cases this model is best suited for.

1.
Favicon for https://nousresearch.com
Hermes Agent
10.7Ttokens
2.
Favicon for https://claude.ai/apple-touch-icon.png
Claude Code
7.94Ttokens
3.
Favicon for https://pi.dev/
pi
6.9Ttokens
4.
Favicon for https://www.strix.ai/
Strix
5.87Ttokens
5.
4.87Ttokens
Rest of OpenRouter
6.07T
Top 5 Apps
1.27T

Activity

Token volume and request traffic to this model over time.

API

Drop-in code to call this model. OpenRouter's API is OpenAI-compatible — most SDKs work by just swapping the base URL. The only thing that changes between models is the model slug below.

DeepSeek: DeepSeek Flash versions

Not currently available through EU in-region routing. In-region routing docs

Documentation

Guides, cookbooks, blog posts, and tools for building with DeepSeek: DeepSeek V4.1 Flash 1017 on OpenRouter.

Frequently asked questions