ChatGPT or DeepSeek: Which Should You Choose in 2026?

“ChatGPT or DeepSeek?” is a common question, and the reasoning is understandable: why pay for ChatGPT if DeepSeek is free and, people say, just as good? In the practical example described here, DeepSeek was tested back in January 2025. ChatGPT was used for everyday tasks, while code was written with Claude Code.

Below, I’ll lay out the differences without taking sides: what’s free, what costs money, how access terms differ, and where your conversations go. Prices and rules are based on the official OpenAI and DeepSeek pages as of September 13, 2026—they change, so check the current information on their websites before paying.

So, which should you choose? The short answer#

I’ve gathered the recommendations in one table. Find your task in it—the recommendation is in the second column.

What are the fundamental differences between DeepSeek and ChatGPT?#

DeepSeek was created by Hangzhou DeepSeek Artificial Intelligence. As of September 2026, its API has two current models: DeepSeek-V4.1-Flash and DeepSeek-V4-Pro. According to the documentation, both accept up to one million tokens of context in a single request. The web chat and app are free; the company charges developers for API access.

ChatGPT is made by OpenAI. In 2026, it runs the GPT-5.6 line and the flagship GPT-6 Astra. Over the years, the service has also gained features DeepSeek doesn’t have: memory between conversations, voice mode, image generation, projects with shared files, scheduled tasks, and the Codex agent for working with code.

The simple breakdown is this: DeepSeek is usually enough for writing and analysis. When I need memory, voice, or projects, I open ChatGPT.

What’s free, and what costs money?#

ChatGPT plans as of September 13, 2026:

The price difference is also reflected in context—the amount of text a model can keep in mind at once. ChatGPT has 27 thousand tokens on Free, 54 thousand on Go and Plus, and 128 thousand on Pro. DeepSeek models are listed with a context window of up to one million tokens, but that applies to API use, not chat.

DeepSeek doesn’t charge for chat. It makes money from API access, and its prices are several times lower than OpenAI’s—I’ll cover them in detail below, in the section about building your own product.

What access and payment terms apply?#

They don’t ask you to add a card because chat is free. Email registration and free chat access were already available in January 2025 and were still available when this material was prepared.

ChatGPT has two separate barriers: access and payment. First, access.

Now, payment. The OpenAI source ties payment eligibility to a card issued to a user in a country supported by the service. With fees, the final cost usually comes out higher than the listed dollar price.

And don’t build your workflow around an account bought from someone else: it could be blocked at any time, and you’d lose your history and settings along with it.

Where is DeepSeek stronger than ChatGPT?#

In the January 2025 test, DeepSeek showed four advantages: it handles complex tasks very well; confidently follows context and logic without losing track; writes commercial copy better than ChatGPT; and is free, with email registration. The model line has since been updated to the fourth generation, while free access and email registration have remained.

For people building their own product, here’s how the costs break down. One million input tokens on DeepSeek-V4.1-Flash costs 15 cents during off-peak hours and 30 cents during peak hours; on the flagship V4-Pro, it costs 66 cents and $1.32, respectively. OpenAI charges $1.25 per million input tokens for GPT-5 and $10 for the flagship GPT-6 Astra. DeepSeek’s output tokens are also several times cheaper: $0.60-1.20 for Flash and $1.98-3.96 for V4-Pro, compared with $10 for GPT-5 and $50 for GPT-6 Astra. DeepSeek’s peak hours are 01:00-04:00 and 06:00-10:00 UTC on weekdays; at other times, including weekends, prices are half as high.

For model IDs, API connection choices, and the limits of price comparisons, see the DeepSeek coding-model guide. It explains how to compare the available DeepSeek models on your own coding task; it is not a measured comparison with Claude Code. Use the same task and count retries and corrections before comparing cost per solved result.

Where is ChatGPT stronger than DeepSeek?#

The same January test showed what DeepSeek lacks as a replacement for ChatGPT: no way to customize the model, no projects for long chains of tasks, and weak integrations. Looking at its website now, the picture is the same: chat, deep thinking, and smart search. DeepSeek has since introduced a full API, which is how the company makes money, but the September 2026 review found no memory, projects, or style customization in its chat.

ChatGPT has all of these features. Memory lets you tell the service once who you are and what you do, and it takes that into account in future answers. Projects keep files and instructions about one topic together. Voice mode is convenient on the go, images can be generated right in the conversation, and scheduled tasks run automatically at the right time. For a detailed look at all of this, see ChatGPT: What It Can Do, How Much It Costs, and How to Use It.

At the same time, memory alone doesn’t do much. AI results depend on what you put into its context: who you are, what rules you follow, and how your project works. This is called context engineering, and it works with either service.

What does each service do with your conversations?#

DeepSeek’s privacy policy states this directly:

The document also makes the rest clear. They collect user input—texts, voice, files, chat history—as well as device data, IP address, and approximate geolocation. They may use this to improve models by default; you can opt out, and this right is stated in the policy. If you use their smart search, the keywords in your queries are sent to third-party search services. The service terms are governed by the law of the PRC.

OpenAI may do the same with conversations. The company says in its help materials that it may use chat content to improve models, and provides two ways to turn this off: disable “Improve the model for everyone” in settings (Settings → Data Controls), or select “Do not train on my content” in its privacy center.

My practice is simple. I put only things I don’t mind sharing into DeepSeek: drafts, ideas, and analysis of public materials. I open work documents in ChatGPT with training on conversations turned off, and avoid uploading sensitive data to either service unless necessary. I recommend the same approach to you.

How can you test both services in an evening and choose the right one?#

The test costs nothing, but assumes you already have lawful access to both services. For ChatGPT, keep the country restriction from the section above in mind.

1. Write down five real tasks of yours and the same source materials

   Choose things you actually deal with: an email to a client, a post for a channel, an analysis of a public document, the structure for a new product, or a spreadsheet calculation. Prepare one prompt and the same source material for both services for each task. Don’t use sensitive documents for the test.

2. Run all five through DeepSeek

   Sign up with your email address at deepseek.com or in the app. Enter each task in a new chat so the previous one doesn’t affect the next. Save the answers without editing them.

3. Run the same five through ChatGPT

   Send the same prompts unchanged to ChatGPT’s free plan, also using a new chat for each. Save the answers alongside the DeepSeek answers in one document.

4. Compare each pair of answers and sort them into three groups

   For each pair, mark: DeepSeek, ChatGPT, or tie. Count as the winner the answer you can use with fewer edits and no noticeable factual errors. If most are ties, keep both and choose based on convenience and price.

5. Decide what you’re willing to pay for

   If DeepSeek handled everything, don’t pay at all. If some tasks are clearly easier in ChatGPT and you’re running into the free plan’s limits, then consider Plus. I compared ChatGPT’s plans with each other in ChatGPT Free, Plus, or Pro: Which Plan Should You Choose?.

Don’t change your workflow after every high-profile release. Repeat this test only when your current service stops handling your tasks.

Frequently asked questions#

I’ve put together short answers to the questions people ask most often.

More materials are available at Ailoot.