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DeepSeek is the AI that made headlines by matching the big players for a fraction of the cost — and giving it away for free. If you’ve heard the name but weren’t sure what the fuss was about, here’s the short version: it’s a surprisingly capable chatbot that costs nothing to use.
Learning how to use DeepSeek takes about two minutes, because there’s no paywall and barely any setup. The harder question is when you’d reach for it instead of ChatGPT. I’ve used both for a while now, and DeepSeek wins in some specific, useful places — and loses badly in others.
Here’s what it does well, the one limitation that’ll surprise you, and the privacy question worth knowing about before you paste anything sensitive in.
What DeepSeek is
DeepSeek is a conversational AI from a Chinese company of the same name. Two things make it stand out: it’s free with no subscription tiers, and its models are open-source, meaning developers can download and run them on their own hardware.
For most people, though, “how to use DeepSeek” just means the free chat app. Its reasoning model, R1, is the star — it thinks through problems step by step and shows its work, which is why it’s so strong on math and code.
How to start using it (it’s free)
Go to chat.deepseek.com or grab the DeepSeek app. Make a free account, and you’re in. No credit card, no trial countdown, no “upgrade to continue” wall after ten messages.
The one button worth knowing is DeepThink (R1). Toggle it on and DeepSeek switches to its reasoning model — slower, but far better on anything logic-heavy. Leave it off for quick, casual questions.
Here’s the whole flow, start to finish:
- Open chat.deepseek.com or the app and create a free account.
- Type your question in the box, exactly like any other chatbot.
- Toggle DeepThink (R1) for anything involving math, logic, or code.
- Turn on Search if you want it to pull in current web results.
Try this now: open chat.deepseek.com, turn on DeepThink, and paste a problem you’d normally give ChatGPT. Watch it reason out loud — that visible thinking is the whole appeal.
What DeepSeek is great at
This is where it earns its reputation. In my testing, DeepSeek matches or beats the free version of ChatGPT on:
- Math and logic. The R1 reasoning model is excellent at multi-step problems, showing each step so you can catch where it went wrong.
- Coding. Writing, explaining, and debugging code is a clear strength, especially for structured, logic-driven tasks.
- Cost. It’s free for everything above. No $20/month tier gating the good model.
[Turn on DeepThink] Solve this step by step and show your reasoning: [PASTE MATH PROBLEM OR LOGIC PUZZLE]. At the end, double-check your own answer and flag anything you’re unsure about.
Pro tip: for a coding bug, paste your code and the error message together and ask R1 to explain the cause before it writes a fix. Understanding the bug beats a copy-paste patch you can’t debug later.
Two more things it’s quietly good at
Beyond math and code, two everyday uses have stuck for me. First, untangling a concept I don’t understand:
Explain [CONCEPT] from first principles, step by step, as if I’m smart but completely new to it. Then give me one analogy and one concrete example.
Second, turning a wall of messy notes into something structured:
Here are my rough notes: [PASTE]. Organize them into a clear outline with headings and bullet points, and flag anything that looks contradictory or missing.
The one big limitation
Here’s the part that catches people off guard: DeepSeek’s main models are text-only. It can’t see images, can’t generate them, and has no voice mode.
So if your workflow involves screenshots, photos, diagrams, image generation, or talking to your AI, DeepSeek simply can’t do it. ChatGPT’s free tier handles all of that. This isn’t a small gap — it’s the single biggest reason DeepSeek won’t replace ChatGPT for a lot of people.
The privacy question
Worth being straight about this: DeepSeek is a Chinese company, and its chat app stores your data on servers subject to Chinese law. For casual questions and homework help, that’s a non-issue for most people.
But I wouldn’t paste confidential work documents, client data, or anything sensitive into it — the same rule I’d apply to any free AI tool, just with extra weight here. If privacy is a hard requirement, use the open-source model self-hosted, or stick with a provider whose data handling you’re comfortable with.
DeepSeek vs ChatGPT: the quick take
| DeepSeek | ChatGPT (free) | |
|---|---|---|
| Price | Free | Free (Plus is $20/mo) |
| Math + reasoning | Excellent (R1) | Good |
| Images + voice | None | Yes |
| Best for | Logic, code, cost | All-round, multimodal |
The downside: if you want one tool that does everything, DeepSeek isn’t it. Skip it if you rely on images or voice. But as a free, razor-sharp reasoning engine sitting next to your main chatbot, it’s hard to beat.
When to reach for DeepSeek instead of ChatGPT
The clean rule is to match the tool to the task:
- Reach for DeepSeek when the job is a math problem, a coding bug, or a logic puzzle — anything where you want to watch the reasoning, and you’d rather not pay.
- Reach for ChatGPT when you need images, voice, file uploads, web browsing, or all-round polish for writing.
Because both are free, the smartest setup isn’t picking a winner — it’s keeping them side by side and letting each task decide. You end up with a two-tool kit that covers almost everything and costs nothing.
A quick reality check
Two things to expect before you move everything over. First, R1 is slower than a normal chatbot reply — that step-by-step thinking takes time, so it’s not the tool for a quick one-liner. Second, the free app gets busy. During peak demand you’ll occasionally hit “server busy” messages or slower responses, which is the trade-off for a completely free service at this scale.
Neither is a dealbreaker. But if you need instant, always-on answers, keep a second chatbot handy for the moments DeepSeek is thinking hard or under load.
Frequently asked questions
Is DeepSeek really free?
Yes. The chat app at chat.deepseek.com is free with no subscription tiers, including the R1 reasoning model. The models are also open-source, so developers can run them for free on their own hardware.
Is DeepSeek safe to use?
For everyday, non-sensitive questions, it’s fine. The caution is data: as a Chinese app, your inputs are stored under Chinese jurisdiction, so don’t paste confidential or personal information. That’s good practice with any free AI tool.
Is DeepSeek better than ChatGPT?
For math, logic, and code on a free budget, it’s right up there. For images, voice, and all-round versatility, ChatGPT wins. They’re built for different jobs, and using both costs you nothing.
What is DeepSeek R1?
R1 is DeepSeek’s reasoning model. Toggle on “DeepThink” and it works through problems step by step, showing its logic. It’s slower than a normal reply but much more reliable on anything that needs real thinking.
Can DeepSeek write and debug code?
Yes — it’s one of its strongest areas. R1 is good at writing functions, explaining what existing code does, and walking through a bug step by step. Paste your code and the error message together for the best results.
The smart way to use it
Don’t think of DeepSeek as a ChatGPT replacement. Think of it as a free, specialist second opinion. Next time you’ve got a math problem, a tricky bit of code, or a logic puzzle, run it through DeepSeek with DeepThink on — and keep ChatGPT for everything visual or spoken.
Want to see how the other challengers compare? Here’s my guide to how to use Grok, the real-time chatbot built into X, and a head-to-head on ChatGPT vs Claude if you’re picking a main assistant.