AI video hook writer for TikTok, YouTube Shorts — scroll-stopping openers
Enter a video topic + pick format (TikTok 7s / YT Short / FB Reel / IG Reel) + pick hook style → AI generates 10 viral openers optimized for the first 3 seconds. Realtime streaming, fast copy.
Video format
Hook style
Why use this tool
TikTok's algorithm measures 3s retention — hooks decide 70% of FYP chance. AI generates punchy hooks that stop scrolls instantly.
Curiosity (hide the key info), contrarian (challenge belief), promise (deliver value), story ('Yesterday I...'), question (direct ask). Diverse for A/B.
TikTok 7s (punchiest), YouTube Short (clear value prop), FB Reel (conversational, older audience), IG Reel (aesthetic, on-screen text).
How to use
- 1Enter video topic in textarea (e.g. 'how to lose weight without fasting', 'iPhone 16 vs 15 Pro review').
- 2Pick video format: TikTok 7s / YouTube Short / FB Reel / IG Reel. Each has its own style.
- 3Pick hook style: Curiosity / Contrarian / Promise / Story / Question.
- 4Hit Generate. After 1s → 10 hooks stream in, numbered 1-10.
- 5Pick 2-3 favorites, copy each. Test on real videos — measure 3s retention.
Video hooks — the single biggest virality factor
On TikTok/Reels/Shorts, 3-second retention is the #1 metric the algorithm measures. If 80% of viewers swipe away in 3s, the video never trends. The hook (opening sentence) is the only weapon to keep viewers.
5 most effective hook styles (per Buffer/Hootsuite research): (1) Curiosity gap — 'I used to think X until...', (2) Contrarian — 'Everyone's wrong about Y', (3) Promise — 'In 30 seconds you'll learn Z', (4) Story — 'Yesterday I...', (5) Question — 'Are you making mistake X?'.
TikTok 7-15s short-form: hook ≤12 words, no rambling. YouTube Shorts 30-60s: hook ≤15 words + clear value prop. Facebook Reel: friendlier tone (older audience), 'Hey...'. Instagram Reel: aesthetic, with optional text-overlay on the hook visual.
This tool builds system prompts by format + style. Claude Haiku 4.5 generates 10 variations for one topic — A/B test 3-5 to find the winner.
- ✓10 hook variations per run
- ✓4 formats: TikTok 7s, YouTube Short, FB Reel, IG Reel
- ✓5 styles: Curiosity, Contrarian, Promise, Story, Question
- ✓Optimized for 3-second hook (TikTok), 5-second (YT Short)
- ✓Vietnamese-natural, 1 accent emoji optional
- ✓Streaming response — realtime text
- ✓Copy per hook
- ✓Rate limit 20 gen/hour/IP
When do you need a hook generator?
1-3 videos a day, hooks bottleneck output. AI generates 10 → pick and edit fast.
1 topic, 3 videos with 3 different hooks → measure 3s retention, learn which style fits your audience.
60s Shorts need hook + value prop in 5s. AI generates 10 'promise'-style options.
Each lesson is a Short. Curiosity hooks keep learners through.
Product with one feature — pick 'contrarian' hooks to stand out from competitors.
Skincare/perfume reviews — 'story' hooks pull emotion, audience trusts more.
Under the hood
Backend /api/ai/hook mirrors caption — streams from Anthropic. System prompt combines FORMAT_NOTES (TikTok punchy 12 words, YT Short 15, etc.) + STYLE_NOTES (5 styles).
Prompt emphasizes 'one opening sentence only', 'diverse — DON'T repeat structures'. Output numbered 1-10. Parser splitHooks() splits via regex /^\d+\.\s/ at line start.
Temperature 0.8 — creative. Max tokens 800 covers 10 hooks (~15 words ≈ 20 tokens each).
FAQ
Are 10 hooks truly diverse?
The prompt requires 'NO repeating Do you know... structure'. Temperature 0.8 ensures variation. 10 hooks usually differ in: structure, opening word, angle, punch level.
English hooks?
Yes, but UI VI deliberately anchors VN. For pure English, use /en/tao-hook.
TikTok 7s vs IG Reel — what's the difference?
TikTok punchy ≤12 words — Gen Z, scrolls fast. IG Reel aesthetic ≤12 words but can pair with text-on-screen overlay.
Is 'contrarian' style safe?
Yes. The AI creates belief-challenging statements but NOT extreme/false. E.g. 'No, X isn't needed for weight loss' — common, not offensive.
Hooks for longer videos (>60s)?
Still usable, especially 'YouTube Short' format. For long-form YouTube, hooks remain important but patterns differ — this tool is optimized for short-form.