DeepSeek: DeepSeek V4.1 Flash
deepseek/deepseek-v4.1-flash
Access DeepSeek V4.1 Flash from DeepSeek using the Puter.js AI API for free.
Get Started// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';
puter.ai.chat("Explain quantum computing in simple terms", {
model: "deepseek/deepseek-v4.1-flash"
}).then(response => {
document.body.innerHTML = response.message.content;
});
<html>
<body>
<script src="https://js.puter.com/v2/"></script>
<script>
puter.ai.chat("Explain quantum computing in simple terms", {
model: "deepseek/deepseek-v4.1-flash"
}).then(response => {
document.body.innerHTML = response.message.content;
});
</script>
</body>
</html>
Model Card
DeepSeek V4.1 Flash is DeepSeek's fast, low-cost chat model, a 552B-parameter Mixture-of-Experts system using a new causal encoder-decoder design that activates 8B parameters while reading a prompt and 16B while generating a response. It succeeds DeepSeek V4 Flash, keeping a 1,048,576-token context window and adding a continuously adjustable reasoning effort setting (1-100).
DeepSeek reports it beating the larger V4 Pro on performance, cost, speed, and total runtime. In DeepSeek's own tests it scored 90.6 on Terminal-Bench 2.1, ahead of Claude Opus 5 (89.1) and GPT-5.6 Sol (88.8), 88.1 on CyberGym versus 84.5 for GPT-5.6 Sol and GLM 5.3, and 74.2 on DeepSWE v1.1 versus 74.0 for Claude Opus 5.
It supports tool calling, and DeepSeek says its KV cache footprint is about a quarter of V4 Flash's for cheaper long-context serving. At $0.15/M input and $0.6/M output tokens, it fits high-throughput coding agents, tool-calling pipelines, and long-context workloads.
Context Window 1M
tokens
Max Output 384K
tokens
Input Cost $0.15
per million tokens
Output Cost $0.6
per million tokens
Input text
modalities
Tool Use Yes
Release Date Sep 10, 2026
Output Speed 267
tokens / sec
Latency 0.90s
time to first token
Model Playground
Try DeepSeek V4.1 Flash instantly in your browser.
This playground uses the Puter.js AI API — no API keys or setup required.
Benchmarks
How DeepSeek V4.1 Flash performs on standard evaluations.
| Benchmark | Score |
|---|---|
| Humanity's Last Exam Cross-domain reasoning | 39.2% |
| SciCode Scientific programming | 51.9% |
| LCR Long-context reasoning | 84.0% |
Scores sourced from Artificial Analysis.
Find other DeepSeek models →
DeepSeek V4 Flash Vision Experimental
DeepSeek V4 Flash Vision Experimental is an experimental multimodal version of DeepSeek's V4 Flash model, released by DeepSeek in August 2026. It is a sparse Mixture-of-Experts model with 284B total parameters and 13B activated per token, and it accepts images (JPEG, PNG, GIF, WebP) alongside text through the same API used for V4 Flash, at the same per-token pricing. DeepSeek reports that it matches V4 Flash on text tasks including agentic reasoning and world knowledge, while adding image understanding for document and chart parsing, visual question answering, and agent workflows that interleave text and images. On multimodal agent benchmarks, DeepSeek's own numbers show gains over the text-only V4 Flash, with Terminal Bench 2.1 rising from 82.7 to 83.9, ApexBench from 26.2 to 36.5, and Agents' Last Exam from 25.2 to 27.3, approaching Anthropic's Opus 4.8 (85.0 on Terminal Bench 2.1). On NL2Repo it trails Opus 4.8, 57.7 versus 69.7.
ChatDeepSeek V4 Pro 0813
DeepSeek V4 Pro 0813 is the production release of DeepSeek's V4 Pro flagship model, a 1.6-trillion-parameter Mixture-of-Experts model with 49B parameters active per token, marking the end of a four-month preview. It keeps the preview's 1,048,576-token context window, 384,000-token max output, and three reasoning modes (non-thinking, high, and max effort). DeepSeek reports large gains over the preview build: Terminal Bench 2.1 rose from 72.1 to 87.9 and DeepSWE from 12.8 to 62.7. At max reasoning effort it scores 80.6% on SWE-bench Verified, matching Gemini 3.1 Pro, along with 90.1% on GPQA Diamond, 87.5% on MMLU-Pro, and a Codeforces rating of 3,206, ahead of GPT-5.4's 3,168. Priced at $0.38 per million input tokens and $1.14 per million output tokens. Pinning the 0813 route locks an application to this exact checkpoint rather than the rolling deepseek-v4-pro alias, useful for agentic coding and long-context reasoning tasks.
ChatDeepSeek V4 Flash (0731)
DeepSeek V4 Flash 0731 is DeepSeek's July 31, 2026 dated checkpoint of V4 Flash, a sparse Mixture-of-Experts chat model with 284B total parameters and 13B active per token. This route runs on Alibaba's infrastructure with a 1,000,000-token context window and adjustable reasoning effort (low, high, max). It was re-post-trained for coding agents and tool use, and DeepSeek reports it scoring 82.7 on Terminal Bench 2.1 (up from 61.8 for the April preview), 76.7 on Cybergym, 70.3 on Toolathlon, and 54.4 on DeepSWE, outscoring the larger V4 Pro preview on these agentic tasks despite far fewer activated parameters. At max reasoning effort it also reaches 89.0% on ARC-AGI-1 and 61.4% on ARC-AGI-2, at $0.02 and $0.04 per task. These figures are vendor-reported and weren't independently reproduced at release. Pinning the dated route locks an application to this exact checkpoint, suited to coding agents, tool-calling workflows, and long-context codebase or document analysis.
Frequently Asked Questions
You can access DeepSeek V4.1 Flash by DeepSeek through Puter.js AI API. Include the library in your web app or Node.js project and start making calls with just a few lines of JavaScript — no backend and no configuration required. You can also use it with Python or cURL via Puter's OpenAI-compatible API.
Integrating DeepSeek V4.1 Flash through the Puter.js AI API is free under the User-Pays Model. Each user pays for their own AI usage through their Puter account.
| Price per 1M tokens | |
|---|---|
| Input | $0.15 |
| Output | $0.6 |
DeepSeek V4.1 Flash was created by DeepSeek and released on Sep 10, 2026.
DeepSeek V4.1 Flash supports a context window of 1M tokens. For reference, that is roughly equivalent to 2,097 pages of text.
DeepSeek V4.1 Flash can generate up to 384K tokens in a single response.
DeepSeek V4.1 Flash accepts the following input types: text. It produces: text.
Yes, DeepSeek V4.1 Flash supports tool use (function calling), allowing it to interact with external tools, APIs, and data sources as part of its response flow.
DeepSeek V4.1 Flash scores 39.5 on the Artificial Analysis Intelligence Index, outperforming 93% of tracked models.
Yes — the DeepSeek V4.1 Flash API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.
Add DeepSeek V4.1 Flash to your app for free
Developers can integrate DeepSeek V4.1 Flash for free using the Puter.js AI API.
With the User-Pays Model, each user covers their own AI usage instead of the developer.