How to write AI prompts for social media captions

"Write an Instagram caption about our new autumn menu" is the kind of prompt most people start with. It produces a caption that could belong to any café in the world, because the tool has to guess everything: who is reading, what is on the menu, what makes it different, how you talk and what you want people to do.

Every guess becomes a generic phrase. The fix is to stop asking the tool to guess. A prompt that takes two minutes longer to write usually saves ten minutes of editing, and the result needs fewer changes to sound like you.

The other common failure is asking for too much at once. "Write a month of posts" gives you thirty variations of the same idea. You'll get better results by prompting one post at a time from a planned list of topics, or by asking for a batch only after you've given the tool your content pillars and the specific facts for each post. Planning comes first; the prompt just turns each planned post into words.

Use these six parts every time. You can write them as short lines; the tool doesn't need full sentences. The examples are for a hypothetical neighbourhood café.

Here's the café prompt written out in full. Swap in your own details. Keep the final instructions; they stop most of the robotic phrasing before it starts.

"You are writing a social media caption for a small neighbourhood café. Reader: local parents and remote workers who come in on weekday mornings. Message: our autumn menu starts Monday and the pumpkin loaf is back. Facts (use exactly, don't add others): pumpkin loaf £3.20, baked each morning by Priya, menu starts Monday 3 November. Platform: Instagram feed post, under 70 words, up to 3 hashtags at the end. Tone: warm, plain, a bit dry; here are two of our past captions to match: [paste]. Action: come in this week, and note the loaf usually sells out by 11. Write three different versions. Don't use exclamation marks, don't start with a question, and don't invent prices, quotes or reviews."

Save prompts that work in a shared document so anyone posting for the business starts from the same place. Our free social media AI prompts template has a page for your brand context and a prompt library.

Keep parts 1 to 3 and 6 the same, and change the platform, length and tone notes. One message written natively for each platform beats one caption pasted everywhere. Check lengths with our free social media character counter rather than trusting the tool's count.

• Instagram: make the first line work on its own, keep the caption tied to what the photo or reel shows, and put a small number of relevant hashtags at the end.
• Facebook: write it like a message to a neighbour; questions and local details work well, and a link can sit in the post.
• LinkedIn: give the business reason or lesson, use short paragraphs with line breaks, and leave out hashtag blocks.
• TikTok: the caption supports the video rather than repeating it; include the words people would search for, as covered in our TikTok SEO guide.
• X: ask for a version that fits the character limit with room to spare, and one point only.
• Google Business Profile: plain, factual and local: what, when, where and the action button you'll use.

The first answer is rarely the best. These short follow-ups fix the most common problems without starting again.

• "Give me five more first lines that start with a specific detail, not a question."
• "Cut this to 40 words without losing the price or the day."
• "Remove every adjective that isn't doing a job."
• "Rewrite this as if the owner were saying it to a regular at the counter."
• "What would a sceptical customer ask after reading this? Answer it in one line."
• "List any claim in this caption that I'd need to prove."
• "Write a version for LinkedIn that explains why we made this change."

The table shows how the same request improves as each part of the formula is added. The results are typical of what to expect, written by us for illustration.

Most bad AI captions come from a handful of avoidable habits.

• Asking for "viral" or "engaging". These words push the tool towards clichés. Describe the reader and the action instead.
• Letting it invent facts. Always say "use only these facts" and check every number before posting.
• Asking for 30 hashtags. Ask for a handful of relevant ones and check them, or use our free hashtag generator as a starting list.
• Pasting customer personal data into tools. Remove names, phone numbers and order details from anything you paste in.
• Using the same prompt for every post. If every caption follows one shape, your feed starts to look automated. Rotate formats: a story, a tip, a question, a list.
• Skipping your own edit. The prompt gets you a draft; your edit makes it a post. Our guide to using AI for social media without sounding like a robot has a five-pass edit.

With Zolyp, which we make, you don't need to paste your brand context into every prompt. Its Brand Brain stores your tone of voice, audience, services, colours and banned topics, and the Create tool uses it every time: type an idea, paste a link or pick a topic, and it writes the caption, designs the visual and adds hashtags for each platform you choose. It publishes to Instagram, Facebook, LinkedIn, Google Business, X, TikTok, YouTube, Pinterest, and Threads, and nothing goes live until you approve it. Lite is $9 a month per brand if you only want to schedule posts you make yourself; the plans that create posts start at $29 a month, with a 3-day free trial.