How do I stop ChatGPT from ignoring my request to keep answers short?
Set a length rule once in ChatGPT's Custom Instructions instead of asking in each message, where it drifts back after a few turns. Tell it to answer in three lines and expand only if you ask. The same question then returns three lines instead of six paragraphs, permanently across every chat.
How to do it
- Open ChatGPT's Custom InstructionsCustom Instructions is where you set rules that apply to every conversation, so a preference holds instead of resetting each turn.
- Write one permanent length ruleAdd an instruction like "answer in three lines, expand only if I ask" so brevity is set once rather than requested per message.
- Ask normally and compareSend your usual question. The same prompt that produced six paragraphs now returns three lines, with detail only when you request it.
Questions that come up
Why does asking for short answers in each message stop working?
A request made inside a single message only shapes that reply. Over a few turns the model drifts back to its default length. Custom Instructions apply to every conversation, so the rule persists instead of fading after a handful of exchanges.
What if I sometimes want the long, detailed answer?
Build the exception into the rule itself. Phrasing it as "answer in three lines, expand only if I ask" keeps replies short by default while letting you pull the full detail on demand, so you are not locked into brevity when a topic genuinely needs more.
Does this apply to every chat or just the current one?
Custom Instructions apply across all new conversations, not just the one you are in. That is the difference from asking in a message: you set the line once and it governs future chats until you change or remove it.
Full transcript
Six paragraphs for one question? ChatGPT's Custom Instructions fix that. Asking for brevity in each message drifts back after a few turns. Set the length rule once: answer in three lines, expand only if I ask. Same question, one field different. Six paragraphs versus three lines. Set your line today. Which instruction would you make permanent?