ChatGPT and Claude have multiple models and modes, and using them according to the task greatly changes your efficiency. Don't overthink it—just remember there are two families: the "fast standard model" and the "deliberate reasoning model."
Standard Model (Fast, All-Purpose)
This is enough for most everyday work. Writing, summarizing, paraphrasing, brainstorming, Q&A, and more. It's fast and cheap, letting you go back and forth at a good pace.
Reasoning Model (Thinks Deliberately)
This is the mode called "extended thinking," "Thinking," and the like. Because it thinks deliberately inside before answering, it's slow and more costly (sometimes several to a dozen-plus times more). In exchange, it shines in situations like these.
- Logic problems involving multiple conditions
- Math, calculation, data analysis
- Designing or debugging complex code
- Checking long passages for contradictions
Important: How You Give Instructions Is Reversed
This is the surprising pitfall.
- For a standard model, give detailed step-by-step instructions ("First do X, next do Y")
- For a reasoning model, don't write the steps—give it only the goal (let it work out the approach itself)
If you specify detailed steps for a reasoning model, you actually constrain its performance. Convey only "what you want to achieve," and leave the how-to to it.
Modes Worth Knowing
- Web search — Turn it on when you need the latest information or fact-checking
- File attachment — Have it read a PDF, image, or data, and ask about its contents
- Projects / Notebook-style — Have it remember the same premises and use it repeatedly while keeping context
How to Choose When Unsure
- First try the standard model
- If you feel the thinking is "shallow" or "the logic breaks down," switch to the reasoning model
- If "the information is old or uncertain," turn on search
- If "you want it grounded in material," attach a file
Standard model for speed, reasoning model for difficulty. Just remember this and you're set.
Note: Model names and lineups update quickly, so check each service's official guidance for the latest (this article's overview is as of May 2026).