Why Generic Captions Fail
"Write me a social media caption for this listing."
That prompt works on any platform. And it performs mediocrely on all of them.
Each platform has different algorithms, different optimal lengths, different hashtag strategies, different user behaviors.
What stops the scroll on Instagram gets scrolled past on LinkedIn. What works on TikTok bombs on Facebook.
One prompt for all platforms = average everywhere.
The Numbers That Matter
| Platform | Max Limit | Optimal Length | Hashtags |
|---|---|---|---|
| 2,200 | 138-150 | 3-5 | |
| TikTok | 4,000 | 150-300 | 3-5 |
| 3,000 | Under 150 | 3-5 | |
| 63,206 | 40-80 | 1-2 | |
| X/Twitter | 280 | Under 280 | 1-2 |
These aren't arbitrary. They're based on engagement research. Shorter captions get more engagement on every platform. The max limit isn't the target.
The Scroll-Stop Formula
Every platform rewards the same thing: stopping the scroll.
The structure:
- Hook - First line does the heavy lifting
- Value - Story, insight, or information
- CTA - Tell them what to do next
The hook is where most AI captions fail.
Generic AI hooks:
- "Just listed this beautiful home!"
- "Excited to announce..."
- "Check out this property!"
Scroll-stopping hooks:
- "This kitchen is why we had 12 offers in 3 days."
- "My client cried when she got the keys. Here's why:"
- "POV: You just found a house $50K under budget."
The first set announces. The second set creates curiosity. Curiosity stops scrolls. Announcements don't.
Instagram: The 138-150 Rule
The specs: 2,200 character max. 138-150 characters optimal for engagement. 3-5 hashtags (not 30—that era is over).
Instagram Prompt Template
Write an Instagram caption for a real estate listing. POST TYPE: Just Listed PROPERTY: 4 bed, 3 bath in Costa Mesa, $1.2M, standout kitchen REQUIREMENTS: - Hook in first line (curiosity, not announcement) - Total caption: 138-150 characters for main body - Include clear CTA - End with 3-5 local/niche hashtags - Tone: Professional but conversational FORMAT: [One-line hook] [2-3 short sentences] [CTA] [hashtags]
Before/After
Generic AI output:
New listing alert! This beautiful 4-bedroom home features modern amenities and is located in a great neighborhood. Contact me for more information! #realestate #home #forsale #listing #realtor #dreamhome #investment #property
Platform-optimized:
This kitchen is why 47 people came to the open house.
4 bed | 3 bath | Costa Mesa
$1.2M | Link in bio
#costamesarealestate #orangecountyhomes #newlisting
TikTok: Captions Are Search Terms Now
The specs: 4,000 character max (expanded 2024). 150-300 characters typical. Captions = SEO now.
The game changed. TikTok is a search engine. Your caption needs keywords people actually type.
Before/After
Generic:
Just sold this amazing property! So happy for my clients who found their dream home. Another successful closing! #justsold #realestate #realtor #sold #closing
Platform-optimized:
142 days on market with the last agent.
14 days with us.
Same house. Different strategy. Here's what we changed
#orangecountyrealestate #relistingtips #howtosellahome #realestatetok #homesellingtips
LinkedIn: The 150-Character Cliff
The specs: 3,000 character max. Truncates at ~150 characters in feed. Click "see more" required for rest.
The implication: You have 150 characters to earn the click. If your hook is buried in the middle, no one sees it.
Before/After
Generic:
The real estate market continues to show interesting trends. Buyers and sellers should stay informed about current conditions. Happy to discuss if you have questions! #realestate #marketupdate #realtor
Platform-optimized:
Orange County inventory just hit a 3-year low.
Here's what that means if you're thinking about selling:
→ Less competition for your listing
→ Buyers have fewer options
→ Pricing power shifts to sellers
What are you seeing in your market?
#realestate #housingmarket #orangecounty
Facebook: Shorter Than You Think
The specs: 63,206 character max (absurd). 40-80 characters optimal for engagement. Shortest platform for best results.
Before/After
Generic:
JUST LISTED! This absolutely stunning 3-bedroom, 2-bathroom home in the heart of Costa Mesa is now on the market! Featuring a beautiful backyard, modern updates, and so much more! Don't miss out on this incredible opportunity! Contact me today for a private showing!
Platform-optimized:
This backyard.
3 bed | Costa Mesa | $895K
Open Sunday 1-4. Who's coming?
The AI Caption Checklist
Before posting any AI-generated caption:
Quality Check:
- First line = scroll-stopper?
- Platform-appropriate length?
- Local/niche hashtags (not generic)?
- Clear CTA?
- Sounds like you?
Red Flags to Catch:
- Starts with "Just listed!" or "Excited to..."
- Uses all 30 Instagram hashtags
- Generic hashtags (#realestate #home #realtor)
- No hook, just description
- Sounds like every other agent
Quick Reference
- Instagram: 138-150 characters, 3-5 local hashtags
- TikTok: 150-300 with searchable keywords
- LinkedIn: Under 150 (truncation point)
- Facebook: 40-80 characters
- The Formula: Hook → Value → CTA
- Red Flags: "Just listed!" / "Excited to announce!" / 30 generic hashtags
Get Platform-Optimized Prompts
Our workshops include complete prompt libraries for every platform with templates for every content type.
Sources
- Sprout Social engagement research
- Later optimal length studies
- Hootsuite platform specifications (2025)