Yeschat

DeepSeek Chat Online

Talk to DeepSeek V4.1 Flash in your browser, switch on thinking mode for hard problems, and compare its answer with GPT, Claude or Gemini.

What Is DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is a chat model from the Chinese AI company DeepSeek, released on September 10, 2026 and updated to DeepSeek-V4.1-Flash-1017 on October 17, 2026; DeepSeek says the update shortened task run time and output length. On YesChat it is the DeepSeek model in the chat, on the Pro plan and above, and you can turn its thinking mode on or off. YesChat is not a DeepSeek product.

What People Use DeepSeek Chat For

Code: write, explain, fix

Paste a function and the error message and ask what is wrong, or describe what you need and get a first version to test.

Math and logic

Ask for a solution with every step written out, then ask why a step works if it is not clear.

Everyday questions and drafts

Summaries, explanations, emails and outlines: ask in plain language and keep the conversation going.

A second opinion

In the YesChat chat you can send the same question to DeepSeek V4.1 Flash and to GPT or Claude and compare the answers.

Thinking Mode or Direct Answers?

DeepSeek V4.1 Flash can answer directly or reason first. You choose with the Thinkdeep switch in the chat.

Quick, everyday answers: thinking off

With Thinkdeep off, DeepSeek V4.1 Flash answers directly, which suits drafts, explanations and quick code help.

Hard problems: thinking on

With Thinkdeep on, the model works through the problem before it answers, which helps on math, logic and tricky code. On YesChat this replaces DeepSeek-R1.

Other models in the same chat

For free everyday use there is GPT-5.6 Luna; for long documents, Gemini 3.1 Pro.

How to Chat with DeepSeek on YesChat

  • Sign in to YesChat

    Sign up for a free YesChat account or sign in.

  • Open the chat with DeepSeek V4.1 Flash

    Click "Chat with DeepSeek V4.1 Flash in YesChat": the YesChat chat opens with DeepSeek V4.1 Flash selected. It needs the Pro plan or higher; a free account can use GPT-5.6 Luna. For hard math or code, turn on Thinkdeep; for code, paste the code and the exact error.

  • Ask and follow up

    Read the answer, ask follow-up questions, or try the same question with another model.

Frequently Asked Questions