Compare the products you will actually use. A chat subscription, an API model, and an agent workflow are different decisions.
FOR: People choosing an everyday assistant or an APICompare the same kind of product
Start with a clear decision: which chat application to use, which API model to integrate, or which environment should run an agent. A model benchmark alone does not describe the complete application around it.
OpenAI documents API billing separately from ChatGPT Plus. Apply the same care to DeepSeek and third-party tools: confirm the exact product, account, and usage terms before comparing a monthly price with a token rate.
Try three tasks you already understand
Use a writing task, a factual task with sources you can check, and one task close to your real work. Give each product the same material and the same definition of a successful result.
Record corrections, missing context, and time spent checking the answer. This comparison guide offers a method; it does not present a benchmark we have run or assign an unsupported winner.
Include the workflow around the answer
Check the features and limits available in your account today: the files you need, the inputs the task requires, tools, exports, and collaboration. Availability can change by plan and rollout.
For API work, include prompt length, retries, caching, tool calls, and the effort needed to integrate the response. For a task in a repository, the agent’s tools and permissions matter alongside the model.
Sources
Start with the original documents. Models and prices change; check the official pages before using them.
01DeepSeek official website02DeepSeek API pricing03ChatGPT Plus and separate API billing