DeepSeek app vs ChatGPT app: the honest comparison

DeepSeek app vs ChatGPT app: the honest comparison

Both apps work. ChatGPT is the smoother product with the weaker cheap intelligence and ads below $20. The DeepSeek app is capable and free but locks you to one lab, and its own inference retains your prompts. The lock-in is the real difference — everything else is taste.

The two apps, side by side

ChatGPT tier details from OpenAI's pricing pages, 29 August 2026. Retention claim from OpenRouter's provider data-policy API, 2 September 2026.

The lock-in problem

This is the part neither app advertises. Sign up and pay for DeepSeek, and your subscription follows DeepSeek — when Z.ai ships GLM-5.3 Flash and the frontier moves, you can't use it without learning a new interface and paying a new subscription. The same trap sits under the ChatGPT app. A first-party app is never the best deal, because "best" changes every few weeks and your provider does not. You are always a bit behind the moment your lab slows down. This is why the model choice should not belong to the app's brand — the argument runs fully in you don't pick a model.

Your data

Running a DeepSeek model through DeepSeek's own inference means your prompts are retained — and per the same provider data, may be used for training. That is okay for some tasks and not for others, and you should get to make that call with the facts. The reason you have a call at all is open weights: the model can be served by anyone, anywhere, and 46 of the 83 providers listed on OpenRouter as of September 2026 run zero-retention policies. Your data does not have to travel to China for the model to answer you. What Plainly does with that fact is stated plainly in does Plainly train on your chats.

The feel of each

ChatGPT is the best-built app in this market. The problem is what sits behind it: below $20 you get the small model — good interface, weak intelligence — and ads. In my own blind writing test, ads appeared next to three of five outputs on the $8 Go plan, and the small context window means quality falls off a cliff once a chat gets going. The DeepSeek app is more utilitarian and reads differently from Western apps; whether that bothers you is taste. What it gives you is the actual frontier of cheap models.

The decision rule

If you never want to think about AI and you're okay with ads, the ChatGPT app is a good option. If you want free forever and can live with the caps, the free ChatGPT tier is a fair deal for one-shot questions. If you want the cheap-model frontier without first-party lock-in — the models that make free vs $5 vs $20 tilt toward $5 — that is the gap Plainly fills: $5 a month, the best available model handled for you, no ads. And if you are a professional with daily frontier work, the premium tiers are worth it; no $5 anything will substitute.

The honest limit

Both apps are fine for what they are. The free ChatGPT tier handles a one-shot question, and the DeepSeek app suits a technical user who is price-sensitive and unbothered by retention. This comparison is about the walls you hit later: the cap, the ads, the lock-in. Those arrive on a schedule, and they arrive in that order.