name: viral-video-short-form description: Complete short-form video optimization for TikTok, Instagram Reels, YouTube Shorts, and Facebook Reels. PROACTIVELY activate for: (1) TikTok content strategy, (2) Instagram Reels optimization, (3) YouTube Shorts creation, (4) Facebook Reels strategy, (5) Short-form hook creation, (6) Vertical video best practices, (7) Trending audio selection, (8) Loop optimization, (9) Quick engagement tactics. Provides: Platform-specific length recommendations, algorithm insights, hook formulas, trending strategies, caption techniques, hashtag optimization, and posting schedules. references: - references/tiktok-algorithm-2026.md - references/youtube-shorts-2026.md - references/instagram-reels-2026.md
CRITICAL GUIDELINES
Windows File Path Requirements
MANDATORY: Always Use Backslashes on Windows for File Paths
When using Edit or Write tools on Windows, you MUST use backslashes (\) in file paths, NOT forward slashes (/).
Short-Form Video Mastery (2025-2026)
Complete guide to creating viral short-form content across TikTok, Instagram Reels, YouTube Shorts, and Facebook Reels.
Platform Overview
Optimal Video Lengths
| Platform | Optimal Length | Peak Performance | Max Length |
|---|---|---|---|
| TikTok | 15-60 seconds | 15-30 seconds | 10 minutes |
| YouTube Shorts | 50-60 seconds | 55 seconds (3x views) | 3 minutes |
| Instagram Reels | 7-30 seconds | 30-90 seconds | 90 seconds |
| Facebook Reels | 15-30 seconds | 15-30 seconds | 90 seconds |
Technical Specifications
| Platform | Aspect Ratio | Resolution | File Format |
|---|---|---|---|
| TikTok | 9:16 | 1080x1920 | MP4, MOV |
| YouTube Shorts | 9:16 | 1080x1920 | MP4 |
| Instagram Reels | 9:16 | 1080x1920 | MP4, MOV |
| Facebook Reels | 9:16 | 1080x1920 | MP4 |
The 1.3-Second Hook Rule
Why 1.3 Seconds?
In 2025, attention spans have shortened to the point where you have just 1.3 seconds to stop the scroll and capture attention.
Hook Success Cascade
First 1.3 seconds: Scroll stop moment
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First 3 seconds: 65% will watch 10+ seconds
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First 3 seconds: 45% will watch 30+ seconds
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Complete video: Algorithmic boost
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Replay: Maximum algorithmic favor
Hook Framework
Second 1: Visual/Audio Grab
- Movement in frame
- Unexpected visual
- Pattern interrupt
- Strong audio cue
Second 2: Value Proposition
- What will viewer learn/feel?
- Clear benefit statement
- Curiosity amplification
Second 3: Curiosity Gap
- Open loop that demands closure
- Question that needs answering
- Promise of payoff
High-Performing Hook Types
| Hook Type | Example | Best For |
|---|---|---|
| Curiosity | "Here's what no one tells you about..." | Educational |
| Controversy | "[Popular belief] is completely wrong" | Thought leadership |
| Story | "I was about to give up when..." | Personal brand |
| Result | [Show end result first] | Tutorials |
| FOMO | "Before this gets removed..." | Time-sensitive |
| Self-ID | "POV: You're someone who..." | Niche targeting |
TikTok Deep Dive
TikTok Algorithm (2025)
Primary Signals:
- Watch time and completion rate
- Replays (highest weight)
- Shares
- Comments
- Likes (reduced weight in 2025)
Cold Start Testing:
- First 200-500 viewers determine initial distribution
- Strong performance triggers expanded reach
- Weak performance limits to followers only
TikTok Best Practices
Content Strategy:
- Micro-niche targeting: 2.5x better distribution
- Trend participation: 41% users join monthly challenges
- Original sounds can go viral
- Educational + entertaining = highest engagement
Technical Optimization:
- Caption text matches algorithm interest categories
- Trending sounds boost FYP placement
- Seamless loops get significant algorithmic boost
- Post 1-4 times daily for maximum growth
Engagement Tactics:
- Reply to comments with video responses
- Duet and Stitch popular content
- Use interactive stickers and polls
- Pin top comments
TikTok Hashtag Strategy
| Type | Examples | Purpose |
|---|---|---|
| Broad | #fyp, #foryou, #viral | Reach (debated effectiveness) |
| Category | #fitness, #cooking, #tech | Topical discovery |
| Niche | #beginneryoga, #airfryer | Targeted audience |
| Trending | [Check Creative Center] | Ride trend waves |
Optimal: 3-5 relevant hashtags mixing niche and category
YouTube Shorts Deep Dive
YouTube Shorts Algorithm
Key Signals:
- Watch time (primary)
- Click-through rate
- Engagement depth
- Subscriber conversion
Unique Advantage:
- Shorts feed long-form recommendations
- 41% faster channel growth with Shorts + long-form combo
YouTube Shorts Best Practices
Content Strategy:
- 55-second versions get 3x more views than 15-second
- Tease long-form content
- Thumbnail still matters for browse features
- CTA increases engagement by 22%
Technical Optimization:
- Title max 100 characters (keyword-rich)
- First frame = thumbnail in some views
- Add #Shorts in title or description
- Closed captions for accessibility
Monetization:
- Shorts Fund and ad revenue sharing
- Drive traffic to monetized long-form
- Build subscriber base for channel growth
YouTube Shorts CTA Strategy
| CTA Type | Placement | Impact |
|---|---|---|
| Verbal | Last 3 seconds | Highest conversion |
| Text overlay | Throughout | Reinforcement |
| End screen | Final frame | Action driver |
| Pinned comment | After posting | Extended engagement |
Instagram Reels Deep Dive
Instagram Reels Algorithm (December 2025)
Key Signals:
- Topic clarity (emphasized in 2025 update)
- Engagement (saves, shares, comments)
- Watch time and completion
- Follows generated from Reel
Algorithm Preference:
- Clear, categorizable content
- Original content over reposts
- Consistent posting cadence
Instagram Reels Best Practices
The 3/8/12 Rule:
- 3 seconds: Hook and capture attention
- 8 seconds: Deepen interest and engagement
- 12+ seconds: Deliver full value
Content Strategy:
- 7-30 seconds for viral potential
- 30-90 seconds for optimal engagement
- 50% of viewers watch without sound
- Captions are non-negotiable
Technical Optimization:
- Trial Reels feature for risk-free testing
- Keyword-optimized captions (SEO shift)
- 3-5 highly relevant hashtags
- Best times: Tuesday-Thursday, 11 AM - 6 PM
Instagram Caption Optimization
Structure:
- Hook line (before "more")
- Value delivery
- CTA
- Hashtags (can be in comments)
Keyword Strategy:
- Instagram shifting from hashtags to keyword-based SEO
- Include relevant keywords naturally in caption
- Think "what would someone search for?"
Facebook Reels Deep Dive
Facebook Reels Algorithm
Key Signals:
- Shares (Facebook's core mechanic)
- Comments and reactions
- Watch time
- Cross-platform performance
Facebook Reels Best Practices
Content Strategy:
- Share-worthy content performs best
- Cross-post from Instagram when relevant
- Vertical video: 70% brand lift vs square
- Entertainment and utility content excel
Technical Optimization:
- 15-30 seconds optimal length
- 9:16 aspect ratio required
- Captions for sound-off viewing
- Best time: Late Friday night/midnight Saturday
Timing Critical:
- First 1-2 hours after posting determine reach
- Weekend posting shows higher views
- Test different times with your audience
Trending Audio Strategy
Why Audio Matters
- 88% of TikTok users say sound is essential
- Algorithms favor content with trending audio
- Content with trending sounds appears on the audio's page
- Early adoption of trending sounds = higher FYP chances
Finding Trending Audio
| Platform | Method |
|---|---|
| TikTok | Creative Center, upward arrow indicator on sounds |
| Built-in leaderboard, trending section in audio library | |
| YouTube | YouTube Music trending, observation in Shorts feed |
Audio Strategy Best Practices
Timing:
- Trending audio changes daily/weekly
- Jump on trends within 24-72 hours
- Use sound while it's rising, not peaked
Selection:
- Match audio mood to content tone
- Consider if lyrics support message
- Original sounds can create trends
- Licensed music for commercial use
Execution:
- Sync cuts to beat drops
- Match energy levels to music
- Use sound as hook element
- Consider sound-off alternative
Looping and Replay Optimization
Why Loops Matter
TikTok engagement weights:
| Action | Weight |
|---|---|
| Likes | 1 |
| Comments | 2 |
| Shares | 3 |
| Complete plays | 4 |
| Replays | 5 |
Creating Seamless Loops
Technical Requirements:
- Last frame transitions to first frame
- Audio loops without break
- Story ends where it began
- No jarring cuts at endpoints
Content Strategies:
- Reveal then tease in same video
- Circular narratives
- Satisfying processes (art, cooking, ASMR)
- Unexpected endings that require rewatch
Loop Performance Stats
- 60%+ completion rate = good
- 80%+ completion rate = viral distribution
- Short 10-second loops pull 3x performance of long-form
- 5-10 second loopable clips perform well due to high replay
Caption and Subtitle Best Practices
Caption Impact
| Metric | Improvement |
|---|---|
| Watch likelihood | 80% higher |
| Engagement | 40% increase |
| Watch time | 10% improvement |
| Retention | 27% higher |
Caption Style Trends (2025)
Visual Styles:
- Animated, bouncing letters
- Liquid transitions between words
- 3D motion synchronized with music
- Highlighted key words with color/effects
- Word-by-word reveal timing
Technical Best Practices:
- Large, readable fonts (mobile-optimized)
- High contrast between text and background
- Position away from UI elements
- Match timing precisely to speech
Platform-Specific Caption Notes
| Platform | Note |
|---|---|
| TikTok | Algorithm reads caption text for categorization |
| 50% watch without sound (per Mosseri) | |
| YouTube | Closed captions improve SEO |
| Auto-captions available but manual is better |
Posting Schedule Optimization
Platform Best Times
TikTok:
- Post 1-4 times daily
- 68% of views happen in first 24 hours
- Posting during audience peak windows improves results by 30%
- Accounts posting 2-4x daily see 2.5x higher follower growth
Instagram:
- Best days: Tuesdays through Thursdays
- Peak times: 11 AM to 6 PM
- 1-2 Reels daily recommended
Facebook Reels:
- Late Friday night/midnight into Saturday = highest views
- First 1-2 hours after posting are critical
YouTube Shorts:
- 1-3 times daily for growth
- Consistent schedule matters more than perfect timing
Posting Strategy
Consistency Beats Perfection:
- Pick a sustainable schedule
- Build audience expectations
- Algorithm rewards consistent creators
Batch Content:
- Create multiple videos in single session
- Schedule ahead of time
- Maintain buffer for flexibility
Quick Reference Checklist
Pre-Publish Checklist
- Hook in first 1.3 seconds
- Correct aspect ratio (9:16)
- Optimal length for platform
- Captions/subtitles added
- Trending or appropriate audio
- 3-5 relevant hashtags
- Clear CTA included
- Loop potential considered
- Title/caption optimized
- Best posting time checked
Content Quality Checks
- Audio clear and balanced
- Visual quality high (1080p)
- Text readable on mobile
- No copyrighted content issues
- Engaging throughout (no filler)
- Value delivered as promised