DeepSeek vs ChatGPT: price, reasoning and code compared

DeepSeek vs ChatGPT: the short answer

DeepSeek wins on reasoning, code and price; ChatGPT 4.1 wins on writing and general knowledge. DeepSeek v4 Flash is even free, while ChatGPT needs at least the Basic plan.

All four models live in the same app, so you can ask both the same question and keep the better answer.

DeepSeek and ChatGPT models head to head

DarkGPT offers two DeepSeek and two ChatGPT models, from 50 to 220 gems per message. Only the DeepSeek models support Thinking mode.

DeepSeek v4 Flash is one of the five models in DarkGPT’s free plan. DeepSeek v4 Pro costs less than a ChatGPT 4.1 message and is available from Basic.

DeepSeek vs ChatGPT for reasoning

On a multi-step problem, DeepSeek v4 Pro is often the best depth-for-price option. ChatGPT 4.1 reasons well on everyday questions, without Thinking mode.

DeepSeek made its name with the way it works through a chain of reasoning: math problems, logic puzzles, financial calculations. With Thinking mode (+40 gems, from Platinum), v4 Pro lays out every step before concluding. ChatGPT 4.1, for its part, is excellent for routine analysis: comparing two quotes, structuring a plan.

Typical cases where v4 Pro earns its 150 gems: a scheduling problem with many constraints, a probability exercise, a comparison of loan offers over several years. Ask it to “verify the answer with a worked example” and it is more likely to catch its own mistakes.

For coding: DeepSeek has the edge

DeepSeek delivers more useful code per gem than ChatGPT. v4 Flash handles most small jobs for free, and v4 Pro takes on the hard problems for 150 gems.

• DeepSeek v4 Flash: explain an error, write a small script, port a function from one language to another.
• DeepSeek v4 Pro: the algorithm that won’t budge, query optimization, program analysis, reverse engineering.
• ChatGPT 3.5 Turbo: fine for simple snippets, less reliable once the code gets complex.
• ChatGPT 4.1: solid and well explained, but pricier than v4 Pro for an often comparable result on pure code.

Kimi, Devstral and Claude join the fight in our comparison of AI models for coding.

For writing: ChatGPT 4.1 has the edge

To write, summarize or explain things to a wide audience, ChatGPT 4.1 is more consistent than DeepSeek. Its answers are well structured, neutral in tone, with few approximations.

DeepSeek writes decently, but its real strength is logic: it goes straight to the solution, while ChatGPT adds context and polishes the presentation. If writing is your main use, also read our Claude vs ChatGPT head-to-head.

On freedom, there is no difference in principle on DarkGPT: models marked Unfiltered mode answer legitimate adult requests without moralizing, whether it is a dark crime novel, a blunt health question or a breakdown of a scam so you can protect yourself.

How many messages a day

With Basic (650 gems a day), you get 13 DeepSeek v4 Flash messages, 4 v4 Pro messages or 7 ChatGPT 3.5 Turbo messages. ChatGPT 4.1 requires Gold.

Without a subscription, the Essential pack (1,500 gems, €15.99) works out to 10 DeepSeek v4 Pro messages or 6 ChatGPT 4.1 messages. Details on the pricing page.

DeepSeek and ChatGPT through the API

The DarkGPT API bills DeepSeek per token, from €0.00281 per 1,000 input tokens. The ChatGPT models are not on the current API price list: you use them from the chat.

Credit starts at €10 and also works with DarkGPT IDE. Everything is explained in our DarkGPT API guide, and the up-to-date model list is on the API page.

Compare both in 4 steps

Start with the free model and only move up when the answer falls short. That way your gems go where they matter.

1. Start with DeepSeek v4 FlashIt is free and already handles most code and logic questions.
2. Move up to v4 Pro if it strugglesWrong reasoning, unsolved bug, multi-step problem.
3. Switch to ChatGPT 4.1 for textPolished writing, summaries, plain-English explanations.
4. Compare on the same questionSend exactly the same prompt to the other model and keep the better answer.

Ready-to-copy prompts

Each prompt is paired with the model that handles it best for its price.

• “Calculate the total cost of this car loan (rate, term, insurance) and show every step.” (DeepSeek v4 Pro)
• “This Bash script returns ‘permission denied’: explain why and fix it.” (DeepSeek v4 Flash)
• “Summarize this news article in 5 neutral bullet points for a newsletter.” (ChatGPT 4.1)
• “Find the logical flaw in this argument, then rewrite it correctly.” (DeepSeek v4 Pro)
• “Give me three simpler ways to phrase this sentence.” (ChatGPT 3.5 Turbo)

Censorship, the third criterion of the duel

DeepSeek and ChatGPT are usually compared on price and reasoning. The third criterion is what they’re willing to say. ChatGPT hedges and warns a lot; DeepSeek, depending on the version, dodges some political topics.

On DarkGPT, DeepSeek v4 Flash and v4 Pro run in Unfiltered mode: history, politics, health, money, they answer straight. ChatGPT 4.1 keeps its caution, but you switch between them in the same conversation.

Adults 18+ only; illegal use is still banned.

Pitfalls to avoid

The main trap is paying a lot for a task a free model does just as well.

• Paying for ChatGPT 4.1 on simple code: 220 gems, more than four DeepSeek v4 Flash messages.
• Turning on Thinking everywhere: it adds nothing to a factual question and inflates the bill.
• Confusing free with unlimited: the free plan gives 50 gems a week, which is one DeepSeek v4 Flash message.
• Giving an incomplete problem: without the numbers, the full code or the exact error message, even v4 Pro is guessing.
• Expecting ChatGPT 4.1 on Basic: Basic includes ChatGPT 3.5 Turbo only; ChatGPT 4.1 comes with Gold.

DeepSeek or ChatGPT: which one should you choose?

Pick DeepSeek for logic, code and small budgets, ChatGPT 4.1 for writing and explanations. By profile:

For everything about the DeepSeek family, read our complete guide to DeepSeek v4 Flash and v4 Pro.

Frequently asked questions