Short-form video isn’t an essay. The script has to win or lose the viewer in the first 3 seconds — and the data is brutal: over 70% of TikTok viewers make their stay-or-swipe decision before second 3, and content that drops below 60% retention in that window gets almost no algorithmic push (per 2026 retention studies, cited below). To get AI to write a script that survives that drop-off, you have to brief it on three things: hook, structure, and CTA.
TL;DR
- Brief the model on a specific hook pattern (conflict, POV, curiosity-gap) and force the first line to land in second 1. Generic openers like “hey guys” are dead on arrival.
- Don’t reuse one script across platforms. Sweet-spot length, pacing, and CTA differ: TikTok ~11-18s for completion (30-60s for storytelling), Reels 60-90s, Shorts 50-58s (as of June 2026).
- Use the copy-ready prompt below, then run the self-critique pass — it’s the single highest-leverage step for completion rate.
- Best model for this in 2026: GPT-5.5 for punchy hooks, Claude Sonnet 4.6 for coherent longer narratives, Gemini 3.1 Pro when the script leans on stats or dates.
Pick the right model first
You don’t need a specialized “script generator” SaaS — the frontier chat models write better hooks than most of them, as of June 2026.
| Model | Best for | Plan / price (USD/mo) |
|---|---|---|
| GPT-5.5 (ChatGPT) | Punchy 3-second hooks, fast variations | Free (tight limits) / Plus $20 |
| Claude Sonnet 4.6 | Coherent 60-90s narrative arcs, natural voice | Free (limited) / Pro $20 |
| Gemini 3.1 Pro | Scripts built on stats, dates, comparisons | Google AI Pro $19.99 |
All three handle a single short script on their free tier. The paid tiers matter only if you’re batching dozens of scripts a day. For the workflow below, any of them works — the prompt does the heavy lifting.
How hooks and structure actually differ per platform
TikTok, Reels, and Shorts all look like “short-form video”, but the opening, pacing, CTA, and sweet-spot length are different. One AI script copy-pasted across all three underperforms on every one.
TikTok
- Hook: conflict or contrast in second 1. “I make six figures and still take the subway.”
- Structure: hook → pain → twist → CTA. The CTA is usually “comment X if you want part 2”.
- Hashtags: 1-2 niche tags.
- Length: 11-18s gets the highest completion and replay loops in 2026; 30-60s is the sweet spot when the story needs room.
Reels (Instagram)
- Hook: aesthetic-forward, identity-coded. “POV: you finally figured out…”
- Structure: visual hook → teach → payoff → follow-CTA. IG rewards saves and shares heavily.
- Hashtags: 3-5, mixed broad + niche; the cover frame matters (it shows in the grid).
- Length: 60-90s currently earns the highest average views; Reels can technically run up to 20 minutes, but anything over 3 minutes isn’t shown to new audiences.
Shorts (YouTube)
- Hook: tip-format or curiosity-gap. “3 things nobody tells you about X.”
- Structure: list / chapters with on-screen numbers, then a pointer to a long-form video on the same channel.
- Hashtags: 1-2 in the description; the title carries the weight.
- Length: Shorts now allow up to 3 minutes (since late 2024), but 50-58s is the engagement sweet spot for a full tip-format payoff.
Same topic, “How to change careers at 30,” written three ways
TikTok (45s):
0-1s: direct to camera. "I quit my job at 31. Took a 50% pay cut."
1-5s: fast cuts — resignation letter close-up, paystub comparison, 2am laptop screen.
5-20s: pain. "I thought I was done. Turns out the real trap at 30 isn't money — it's
refusing to admit you're a beginner again."
20-35s: twist. "I did one thing: I rewrote 8 years of experience as a list of
transferable skills, then re-applied."
35-42s: result. "3 months later, offer in hand, salary 1.2x my old one."
42-45s: CTA. "Want the skill-translation template? Comment 'send'."Reels (60s):
0-3s: cinematic shot — hand closing a laptop in a sunlit cafe. Burned-in caption
"31. Career change. No backup plan."
3-15s: voiceover over b-roll. "Everyone told me 30 was too late. They were measuring
the wrong thing."
15-45s: three insights, each with one beautiful cutaway shot.
1. Age isn't a liability — it's a story.
2. Your skills already translate. You just haven't named them.
3. The first 90 days are about credibility, not competence.
45-55s: payoff scene — sunset, walking, voiceover "I'd do it again at 35".
55-60s: CTA. "Follow for the rest of the rewrite."
Cover frame: the sunlit laptop shot. Palette: warm amber + muted beige.Shorts (55s):
0-2s: burned-in title "Changing careers at 30 — what actually worked".
2-12s: tip 1. Big "1" caption. "Don't quit first. Validate with weekend projects
for 90 days."
12-22s: tip 2. "Rewrite your resume in the new industry's language."
22-32s: tip 3. "Get coffee with 3 people already inside — ask what to avoid, not
how to get in."
32-42s: tip 4. "Plan for a 30% pay cut, with a 6-month recovery line."
42-50s: tip 5. "Ignore anyone who says 30 is a deadline. It isn't."
50-55s: pointer. "Full 20-minute breakdown is the next video on this channel."
Faster pace than IG, more on-screen text.A structure that works
| Beat | Time | Job |
|---|---|---|
| Hook | 0–3s | Stop the scroll (target 80%+ retention here) |
| Payoff | 3–30s | Demonstrate / inform (hold above 60% to midpoint) |
| Twist | 30–45s | Earn the like / share |
| CTA | 45–60s | Follow / comment / save |
The retention targets in that table aren’t guesses: 2026 Shorts benchmarks call for 80%+ retention in the first 3 seconds, 60%+ through the midpoint, and a 70%+ average-percentage-viewed to finish. Write to those numbers, not to a word count.
The prompt
Paste this:
You are a senior short-form video scriptwriter for TikTok / Reels / Shorts. You specialize in scripts that survive the first 3-second drop-off.
My video topic: [one sentence — e.g. "Use ChatGPT to read a 50-page financial report"]
Platform: [TikTok / Reels / Shorts]
Style: [pick one: how-to / emotional / storytelling / comparison-review]
Length: 60 seconds
Please output:
1. Three different "first 3-second hooks". Mark the strongest with a star.
2. A full script, segmented by time, with shot suggestions for each segment (e.g. iPad screen recording / close-up / walking shot).
3. Three usable video titles (with one tasteful emoji each).
4. A set of hashtags.
Voice: natural, conversational, no AI-ish phrasing, no "hey guys" filler.Make it self-critique
After the first draft:
Act as a stranger encountering this video for the first time. List the 3 most likely reasons they swipe away within the first 5 seconds, and rewrite the opening 5 seconds.This single step has an outsized effect on retention, because the first 3 seconds are where most of the loss happens. Run it before you change anything else in the script.
Reusable hook patterns
- “I tried X. Here’s what surprised me.”
- “If you’re stuck at X, this saves you 3 months.”
- “Everyone says X. Actually, it’s the opposite.”
- “Three seconds. Most people don’t know this.”
Get AI to rotate through these across videos so they don’t feel formulaic. Paste 2-3 of your own past openers into the prompt so the model matches your voice instead of defaulting to template phrasing.
Reusable CTA patterns
- Follow for one “AI does it for me” trick a day.
- Drop the topic you want next in the comments.
- Save this — you’ll need it next time.
Watch-outs
- Avoid “hey guys, what’s up.” Viewers are immune.
- Use concrete numbers: 3 things / 5 ways / 80% of people miss this.
- Always rehearse the script out loud. AI prose sometimes doesn’t flow on camera — small word swaps fix it.
- The model writes lines, not shots. Add the camera direction yourself, or it’ll read like a blog post on screen.
From script to finished video
Once the script is locked, AI tools can carry it the rest of the way: text-to-speech voiceover, auto-captions, and even generative b-roll. If you’re going hands-free, see our AI video from script workflow for the script-to-render pipeline.
Summary
Short-form video isn’t writing — it’s performance. AI shrinks “idea → executable script” to about five minutes. The remaining 95% is delivery and editing, and the single number that decides whether any of it matters is your 3-second retention.
FAQ
Q: Why does my AI-generated short-video script lose viewers in the first 3 seconds? A: Most AI scripts open with “hey guys” or a generic claim, which audiences are trained to skip — and over 70% of viewers decide whether to stay within those 3 seconds. Brief the model on a specific hook pattern (conflict, POV, or curiosity-gap) and ask for the first line to land in second 1.
Q: Should I use the same script for TikTok, Reels, and Shorts? A: No. Hooks, pacing, and CTAs differ per platform. TikTok rewards conflict openers and comment-based CTAs (11-18s for completion), Reels rewards aesthetic POV hooks and saves (60-90s), and Shorts rewards list-format openers that point to long-form video (50-58s). Ask the model to write three separate scripts from the same topic.
Q: How long should an AI-written short-video script be? A: As of June 2026: TikTok completes best at 11-18s but runs 30-60s for storytelling; Reels peaks at 60-90s; Shorts allow up to 3 minutes but engage best at 50-58s. Ask the model to target word count for roughly a 0.4-second-per-word read.
Q: Which AI model is best for short-video scripts? A: GPT-5.5 (ChatGPT) writes the punchiest 3-second hooks; Claude Sonnet 4.6 is strongest on coherent 60-90s narrative arcs and natural voice; Gemini 3.1 Pro is the safer starting point when the script depends on stats, dates, or prices. A single script fits inside every free tier.
Q: How do I get the AI to self-critique a weak script? A: After the first draft, run a pass that asks the model to play a first-time viewer and name the 3 reasons they’d swipe away in 5 seconds, then rewrite the opening. Don’t touch the middle until the hook is fixed — that’s where most retention is lost.
Related
- Reel hook — focused work on the opening 3 seconds
- TikTok hook AI — TikTok-specific hook variants
- Short-form video hook AI — hooks across all short-form platforms
- Viral shorts story arc prompts — story arc within 60 seconds
- Social caption AI — caption paired with the script
- AI video from script workflow — script → finished video
Tags: #Short video #TikTok #Script #Prompt