In short
Use “Quick” for everyday questions, short texts and fast checks: it replies briefly and fast. Use “Deep” for comparisons, long documents and tasks with several steps: it takes more time and answers more thoroughly.
- Switch
- Button next to the input field
- New chats
- Always start in Quick
How to switch between Quick and Deep
- Open a chat with Alt+1 or Alt+2. It starts in “Quick”.
- Click the “Quick” button next to the input field. It changes to “Deep”.
- Ask your question. The following answers in this chat use Deep.
- Click the button again to go back to Quick. You can switch between questions in the same chat, but not while an answer is running.
- For a Deep version of an answer you already got in Quick, switch to Deep and click “Generate another answer” below that answer.
What is the difference between Quick and Deep?
| Quick | Deep | |
|---|---|---|
| Answers | Brief and fast | More thorough, take more time |
| Answer length | Follows your “Answer length” setting | Longer answers at the same setting |
| Web search | Searches | Searches and can read single pages in full |
| Credits per question | Fewer | Several times as many |
Which tasks suit which mode?
- Quick: “What does pro rata mean in this invoice?”, a reply to a short email, a word in another language, a check of one sentence.
- Deep: “Compare these two quotes and list every difference in price and terms”, a summary of a long contract, a plan with several steps, a tricky calculation or code question.
If a Quick answer feels shallow, switch to Deep and generate another answer instead of asking again from scratch. When the AI’s reasoning is available, click the “Thought for …” line above a Deep answer to read it.
Why does the mode button show a lock?
Then Deep is not included in your plan; clicking the button shows which plans include it, see Is Zack KI free?.
With your own API key, Deep is always available: you choose which model answers as Quick and which as Deep. See bring your own API key.
Which mode do the shortcuts use?
Alt+1 and Alt+2 open a new chat in Quick. Alt+Shift+1 reopens your last chat in the mode it last used. Alt+3 (“Improve”) and Alt+4 (“Fix errors”) always run in Quick, see Fix text with AI.
Related questions
Does Deep always give better answers?
No. For simple questions, Deep takes longer and uses more credits without a better result.
Can I make Deep the default?
No. Every new chat starts in Quick. A chat you reopen from the list keeps the mode it last used.
How many more credits does Deep use?
Several times as many per question as Quick. The exact amount depends on the question, attachments, the length of the answer and any web searches.