DeepSeek
DeepSeek V4.1 Flash
Released 
September 2026

DeepSeek
DeepSeek V4.1 Flash

Open-weight MoE model posting frontier agentic-coding scores at Flash pricing, with native vision and 1M context.

model ID
deepseek/deepseek-v4.1-flash

Input price

0.9
Anytoken

Output price

3.6
Anytoken
DeepSeek V4.1 Flash: Frontier Agentic Coding at Flash Speed and Cost DeepSeek V4.1 Flash is an open-weight, MIT-licensed multimodal Mixture-of-Experts model from DeepSeek. It is the smallest model in DeepSeek's new V4.1 architecture family, built on a Causal Encoder-Decoder backbone with 552B backbone parameters that activates only 8B parameters per input token and 16B per output token. That asymmetric design targets input-heavy agentic and coding workloads where cost and throughput dominate. It natively processes text and images, generates text, supports a 1M-token context, and reports leading agentic-coding benchmark scores while remaining fast and inexpensive to call repeatedly. Start building with DeepSeek V4.1 Flash through the AnyAPI.ai API.

Performance

Why V4.1 Flash Punches Above Its Active Parameter Count

V4.1 Flash is built for agentic coding and tool-driven loops. DeepSeek reports 90.6 on Terminal-Bench 2.1 and 74.2% on DeepSWE v1.1, results that lead or match much larger models on these provider-run harnesses. Because the Causal Encoder-Decoder activates only 8B parameters on input and 16B on output, the model stays fast (Artificial Analysis measured about 207 tokens/second) and cheap enough to call repeatedly. For production agents that iterate over code and tools across many turns, that combination of capability, throughput and low per-call cost is the decisive factor.

Benchmarks

Independent Reads: Fast, Capable, and Notably Verbose

Artificial Analysis places DeepSeek V4.1 Flash (Reasoning, Max Effort) at 40 on its Intelligence Index v4.3, well above the median for comparable models, and measures roughly 207 tokens per second. The same evaluation flags high verbosity: the model generated about 250M tokens versus a 140M median, meaning strong intelligence comes with longer reasoning traces. Independent coverage confirms the agentic-coding lead but notes weaker world knowledge and rough edges on some tasks. Treat provider benchmark figures as harness-specific and re-test under your own scaffold before committing.

Technical Specifications

What the model supports

DeepSeek V4.1 Flash accepts text and image input and returns text only; it is not an image or audio generator. It supports a 1M-token context window with maximum output around 384K tokens, so long inputs and long generations are both feasible, though they are separate limits. The model ships with thinking / non-thinking modes and configurable reasoning effort. Its aggressively compressed KV cache (roughly 890 bytes per token) is the highest-impact production detail: cache-hit charges that usually dominate agent costs shrink substantially, favoring repeated-context, high-volume workloads.
Verified Specifications — 
DeepSeek V4.1 Flash
*
Reasoning
Yes
Knowledge cutoff
September 2026
Pricing (standard)
0.9
 AnyTokens in
 / 
3.6
 AnyTokens out

Comparison

DeepSeek V4.1 Flash vs DeepSeek V4 Pro: Which One Should You Run?

These two are the realistic decision within DeepSeek's lineup. V4 Pro is the larger 1.6T-parameter (49B active) flagship; V4.1 Flash is the smaller, newer model built on the V4.1 Causal Encoder-Decoder architecture. Both share a 1M-token context and MIT-licensed open weights. DeepSeek reports that V4.1 Flash surpasses V4 Pro on most agentic benchmarks it publishes, while costing less, running faster, and completing tasks in less total runtime. DeepSeek briefly planned to route V4 Pro traffic to Flash before reversing that decision, so V4 Pro remains available at its own rates.

Dimension
DeepSeek V4.1 Flash
DeepSeek V4 Pro 0813 (Reasoning, Max Effort)
Input pricing
0.9
AnyToken
9.6
AnyToken
Output pricing
3.6
AnyToken
19.2
AnyToken
Knowledge cutoff *
September 2026
April 2026

Choose DeepSeek V4.1 Flash when your workload is agentic coding at volume, when you need native image input, or when throughput and low per-call cost matter more than raw world knowledge. Choose DeepSeek V4 Pro when factuality and broad knowledge are critical: V4 Pro scores materially higher on knowledge tasks like SimpleQA, and V4.1 Flash's world knowledge regressed relative to V4 Pro. If your agents lean on recall of facts rather than tool-driven coding, Pro is the safer default until V4.1 Pro ships.

Limitations & Trade-offs

Where DeepSeek V4.1 Flash falls short

1
High verbosity inflates output. Artificial Analysis measured V4.1 Flash generating roughly 250M tokens on the Intelligence Index versus a 140M median. Because strong scores come with long reasoning traces, effective output cost and latency per completed task can rise even though the per-token price is low. For latency-sensitive or budget-capped generation, lower the reasoning effort or use non-thinking mode, and validate that verbosity does not erase the model's cost advantage in your workload.
2
Weaker world knowledge and factuality. Independent coverage notes V4.1 Flash's world knowledge regressed versus V4 Pro (SimpleQA around 42.3 vs 55.2), and its Humanity's Last Exam score of 36.8 trails frontier proprietary models. For trivia, factual Q&A, or knowledge-heavy RAG where the model must supply facts rather than reason over tools, a higher-knowledge model such as V4 Pro or a frontier proprietary model is preferable.
3
Provider benchmarks are harness-specific. DeepSeek's headline scores (e.g. 90.6 Terminal-Bench 2.1, 74.2% DeepSWE) are provider-run under specific scaffolds; the same model scores differently across harnesses (DeepSWE ranges from 65.6 on Codex to 74.2 on mini-SWE-agent). Independent trackers flag these launch rows as display-only rather than ranked. Reproduce results under your own agent framework before treating them as production guarantees.
4
Early operational rough edges. As a newly released model on a new architecture, independent testing found rough edges on some tasks, and the release does not ship a Jinja-format chat template (DeepSeek instead provides a reference encoding and its own recipe libraries). Teams integrating outside the OpenAI-compatible endpoint should budget setup time and test the prompt format carefully.

Best-Fit Workloads

Where this model earns its place

01

Agentic coding at volume


This is the model's strongest fit. Leading provider-reported Terminal-Bench 2.1 (90.6) and DeepSWE v1.1 (74.2%) scores, combined with high throughput and low per-call cost from the 8B/16B active design, make V4.1 Flash well suited to coding agents that iterate over files and tools across many turns. The compressed KV cache reduces cache-hit charges that dominate long agent sessions. Validate the harness-specific scores under your own scaffold first.

02

High-throughput tool-calling pipelines


With native tool calling, JSON output and ~207 tokens/second measured output speed, V4.1 Flash fits automation and orchestration loops that call functions repeatedly. AutomationBench results (54.8) reported by DeepSeek support agentic tool use. The economics favor systems that fire many small requests rather than a few large ones; watch verbosity so long reasoning traces don't inflate cost per completed action.

03

Long-context repository and document work


The 1M-token context lets V4.1 Flash ingest whole-repository traces or large document sets in a single prompt, and the compressed KV cache keeps that practical. Native image input additionally supports document-with-figures and chart understanding (Chartography 78.9, DocVQA 95.6 reported). Because maximum output is separately capped around 384K tokens, structure very long generations accordingly.

04

Multimodal developer workflows


V4.1 Flash is the first GA DeepSeek Flash model with native vision, removing the need for a separate vision endpoint. It can interleave images and text for UI-to-code, chart/diagram interpretation, and screenshot-driven agent tasks. It only accepts images as input and outputs text, so it does not replace an image generation model. Verify visual-task accuracy for your domain, as vision benchmarks vary by scaffold.

Pricing in anytokens via AnyAPI
Input
0.9
Output
3.6
Cache write
Cache read
0.018

Integration

Access DeepSeek V4.1 Flash via AnyAPI.ai

Access DeepSeek V4.1 Flash through AnyAPI.ai using a unified API built for multi-model AI applications. Integrate DeepSeek V4.1 Flash without maintaining a separate provider-specific connection, and keep the flexibility to test, switch, or combine models as your application requirements evolve.

01

One API integration

Access DeepSeek V4.1 Flash and other AI models through the same API workflow instead of maintaining separate integrations for every provider.

02

Easy model switching

Test DeepSeek V4.1 Flash against alternative models or switch models as your performance, capability, or cost requirements change without rebuilding your application around another provider API.

03

Flexible for production

Use DeepSeek V4.1 Flash from experimentation through production while keeping your AI stack flexible as workloads, traffic, and model requirements evolve.

04

Multi-model applications

Use DeepSeek V4.1 Flash for the workloads where it performs best and combine it with other models for tasks that require different capabilities, performance, or efficiency.

Frequently Asked Questions

Answers to common questions about integrating and using this AI model via AnyAPI.ai

DeepSeek V4.1 Flash is strongest at agentic coding and tool-driven workloads. DeepSeek reports leading provider-run scores such as 90.6 on Terminal-Bench 2.1 and 74.2% on DeepSWE v1.1, and it combines high output speed with low per-call cost thanks to its 8B/16B active-parameter design, making it practical for coding agents that iterate many times.

DeepSeek V4.1 Flash supports a 1M-token context window (1,048,576 tokens) and a maximum output of roughly 384K tokens (up to 393,216) per response. Context window and maximum output are separate limits: the 1M figure covers total input plus context, while output length is capped independently.

Yes. DeepSeek V4.1 Flash natively processes both text and images and generates text. It is the first generally available DeepSeek Flash model with native vision, so no separate vision endpoint is needed. It accepts images as input only and does not generate images or audio.

Yes. DeepSeek released V4.1 Flash as open weights under an MIT license, with the model available on Hugging Face. It is a 552B-backbone Mixture-of-Experts model that activates only 8B parameters per input token and 16B per output token, and it can be self-hosted on GPU infrastructure in addition to being served via API.

DeepSeek reports that V4.1 Flash surpasses the larger V4 Pro on most agentic benchmarks while running faster and costing less. However, V4 Pro retains stronger world knowledge and factuality (higher SimpleQA scores). Choose V4.1 Flash for agentic coding at volume; choose V4 Pro when broad factual knowledge is critical.

* Benchmark data source: Artificial Analysis artificialanalysis.ai