横動画ショーツ変換 — AIテキストオーバーレイ | Fairmont AI

横動画をAI生成の目を引くテキストオーバーレイ付きで縦型YouTube Shortsに変換。既存の字幕を維持します。

Convert any landscape (16:9) video into a vertical YouTube Short (9:16) while keeping all existing burned-in subtitles fully visible. Instead of cropping the original video, we letterbox it — centering the full frame in the vertical canvas with a blurred background — and automatically generate eye-catching top and bottom text overlays using AI.

How to Convert a Landscape Video to Shorts

  1. Paste Your Video URL: Paste a YouTube, TikTok, Instagram, or any supported platform URL into the input field.
  2. Click Convert to Short: We download the video, generate AI text overlays, and render the 9:16 vertical version automatically.
  3. Download Your Short: Download the finished vertical video with AI-generated top hook and bottom caption burned in.

Frequently Asked Questions

Will my existing subtitles be visible?

Yes. We letterbox your video — the full frame is centered inside the 9:16 canvas — so any burned-in subtitles remain completely visible and uncut.

How is this different from Shorts Maker?

Shorts Maker transcribes the audio and adds new AI-generated subtitles. This tool is for videos that already have subtitles burned in — it reformats to vertical while keeping the original content intact and adds attention-grabbing text in the empty space.

What video platforms are supported?

YouTube, TikTok, Instagram, Twitter/X, LinkedIn, Facebook, and most publicly accessible video platforms that yt-dlp supports.

How long can the video be?

Up to 10 minutes. Shorter clips (under 3 minutes) produce the best Shorts content anyway.

Can I use a vertical video?

No — this tool is specifically for landscape (16:9) videos. If your video is already vertical, it doesn't need conversion.

What does the AI generate?

The AI reads your video title and generates a punchy UPPERCASE hook (top text) and a conversational summary caption (bottom text) designed to maximize viewer curiosity and watch time.

How many credits does it cost?

2 credits per conversion. That covers the video download, AI text generation, and FFmpeg rendering.