Prompt for summarize text with maximum number of characters

I struggling to create a proper prompt for text summarization. The issue is I want to summarize with given number of characters, but usually I got back a longer response. And it’s important to fit into the limit.
I tried a bunch of prompt, but what worked best so far:

  • Summarize text in {numOfChar} character or less! “”“{Text}”“”

  • Summarize text in {numOfChar} character or less! Text: “”“{Text}”“” Summary:

Any help is appreciated!

lower the temperature and provide the number of sentences in the instruction.

For example:

Summarize the following text in `three sentences`, focusing on the topic...

Text: """

Only gpt-4 can produce the exact number of words and sometimes characters, the chatgpt models can mostly summarize based on a given number of sentences, but not characters.

I recently wrote a book about generating prompts for ChatGPT that you might find useful. It is called ‘CHATGPT PROMPT GENERATOR: Unlimited Prompts with ONE’.

You can use this prompt generator to get effective prompt from Chatgpt.

I offer actually free copies for testing just send me an email at to get it.

Good luck!