AI Script Writer for YouTube
Hook-tuned, transcript-aware, search-demand-injected. Type a niche or paste a competitor URL — ViralMint writes a script structured for YouTube's retention curve, not a generic essay. Free daily allowance, no subscription.
Why a YouTube-specific AI script writer beats ChatGPT
A generic ChatGPT prompt for a YouTube script returns an essay-shaped response: introduction, three points, conclusion. That structure tanks retention on YouTube because viewers drop in the first 8 seconds without a hook. A YouTube-specific AI script writer has to be tuned for the platform's retention curve — hook in the first 1.5 seconds, problem statement by second 8, payoff by second 25, CTA at the end — and ideally fed with signals about what's actually working in the niche right now, not a year-old assumption from training data.
ViralMint's script writer is built around three differentiators a generic prompt can't replicate: it's hook-tuned (the system prompt is structured around YouTube + Shorts + TikTok retention research, not generic writing rules); transcript-aware (paste a competitor URL and it Whisper-transcribes the video locally, feeding hook structure and cadence to the prompt); and search- demand-injected (a YouTube Search Suggest probe runs on your topic before writing, so the script targets question- shaped queries with real demand instead of a guess).
How the AI script writer works
- Type a niche or paste a URL. "Why Tesla earnings missed", "iPhone 17 hidden features", "value investing for beginners" — or a YouTube/TikTok URL the script should learn from.
- Search-demand probe. ViralMint pings YouTube Search Suggest with your topic and pulls the top autocomplete completions — the question-shaped queries people are actually typing. These get fed to the script prompt as targets the hook should land on.
- Optional: transcript signal. If you included a competitor URL, ViralMint downloads the video (yt-dlp, local), transcribes it with Whisper (local, free), and AI-extracts the hook structure (first-line opening, tension setup, payoff timing). The signal feeds the script prompt as a structural reference.
- Generate. The cloud chat model (Sonnet 4.6 for heavy scripts, Gemini 2.5 Flash for short ones — auto- routed) writes a script targeting the platform you specify (Shorts / long-form / TikTok). Output includes scene-by-scene structure with caption-friendly punctuation.
- Hand to Smart Video, or copy out. The generated script becomes an input to Smart Video (one click → finished mp4 with voice + captions + stock), or copy it to your own filming/editing workflow if you want to read it on camera.
What makes ViralMint's script writer different
Hook-tuned retention curve
System prompt is structured around YouTube + Shorts + TikTok retention research — hook in 1.5s, problem by 8s, payoff by 25s. Not generic essay shape.
Transcript-aware
Paste a competitor URL. ViralMint downloads with yt-dlp, transcribes with Whisper locally (free), AI-extracts the hook structure, feeds the signal to the script prompt.
Search-demand probe
YouTube Search Suggest autocomplete runs on your topic before writing — the script targets question-shaped queries that have real demand, not a guess from training data.
Platform-aware structure
Output structure adapts: Shorts get a 5-scene 9:16 pacing, long-form gets a B-roll-friendly cadence, TikTok gets hashtag-aware copy. One topic → three platform-specific scripts.
Multi-language
Script writer accepts any target language. Edge TTS covers the voiceover step in 100+ languages free. Caption sync uses Whisper word-level timestamps, which supports 99 languages.
One click → finished video
Generated script hands directly to Smart Video — same window, no copy-paste. Adds voice + captions + stock footage + music and renders the mp4 without leaving the page.
From script to finished mp4 — same pipeline
The AI script writer isn't a standalone tool — it's the first step in ViralMint's Smart Video pipeline. Once you have a script, one click runs the 10 remaining steps: voiceover generation, Whisper transcription for caption timing, Pexels stock search or AI b-roll generation, FFmpeg stitching, music mixing, caption burn, thumbnail extraction, AI-drafted YouTube title and tags, and AI-drafted TikTok caption. Typical end-to-end time from "type a niche" to "downloaded mp4" is 4-8 minutes on the free Pexels tier, 10-18 on the premium AI-video tier.
The integration matters because most AI script writers leave you stranded with a Google Doc full of text. You still have to record voiceover, find stock, edit, caption, and design the thumbnail. ViralMint does all of it from the same interface, with the script as the input and a finished finished mp4 as the output.
Frequently asked
What does an AI script writer for YouTube do differently than ChatGPT?
A generic ChatGPT prompt for a YouTube script returns an essay-shaped response: introduction, three points, conclusion. That structure tanks retention on YouTube because viewers drop in the first 8 seconds without a hook. A YouTube-specific AI script writer is tuned for the platform's retention curve — hook in the first 1.5 seconds, problem statement by second 8, payoff by second 25, CTA at the end. ViralMint also injects YouTube Search Suggest data and (when you provide a competitor URL) Whisper transcripts from existing viral videos, so the script writes against actual demand and existing hooks, not a guess at what works.
Can ViralMint's AI script writer learn from a competitor's existing video?
Yes. Paste a YouTube, TikTok or Douyin URL into the script writer and ViralMint will download the video (yt-dlp), transcribe it with Whisper (local, free), extract the hook structure with AI, and feed those signals to the script-writer prompt. The output is your own original take on the topic, structured around what's already working — not a copy of the competitor's script. Same workflow for batch mode: feed it a folder of 5-10 competitor URLs from the trending video finder and it picks up cross-video patterns.
Is the AI script writer free?
There's a free daily allowance on the cloud AI calls that power the script writer. Past that, scripts cost per use via prepaid USD top-ups (no subscription) — typical cost per script is under 5 cents because scripts are short (~500-1500 tokens). Whisper transcription of competitor URLs runs locally on your desktop for free. Free Edge TTS voiceover for the resulting script is also free locally; paid OpenAI gpt-4o-mini-tts is $0.03 per 1000 characters if you want premium voice quality.
Can I write scripts in languages other than English?
Yes. The script-writer prompt accepts any target language — Spanish, Portuguese, Mandarin, Japanese, German, French, Korean, Arabic, Hindi and more — and the cloud chat models (Sonnet 4.6, Gemini 2.5 Flash, gpt-5.4-mini) are strong multilingual writers. Voiceover via Edge TTS covers 100+ languages free. Caption sync uses Whisper word-level timestamps, which supports 99 languages natively.
Can ViralMint write a long-form YouTube script (10+ minutes)?
Yes. The script writer accepts a target length parameter — 45-60 seconds for Shorts/Reels, 5-15 minutes for typical long-form, up to 30 minutes for podcast-style content. Longer scripts get a different system prompt focused on sustained retention (chapter breaks every 90-120s, B-roll cue density per segment, callback structure across chapters) rather than the short-form hook-only structure.
Write your first script
Sign up takes 30 seconds. The browser version covers the AI script writer via the Chat page. The full Smart Video pipeline (script → voice → captions → finished mp4) ships in the free desktop app.