Auto-Format for Socials
Free Video Aspect Ratio Resizer
Convert landscape videos to Reel-ready vertical formats with Auto-Blur Background.
No Cropping • No Black Bars • No Watermark
Resize Video for Social Media
Convert landscape to portrait (9:16) with auto-blur background. No watermark.
Resize Video for TikTok, Instagram & YouTube
Repurposing content is the key to growth. But taking a wide YouTube video (16:9) and posting it on TikTok (9:16) usually results in tiny videos with huge black bars.
SubCaption's Aspect Ratio Resizer solves this by adding a professional "Gaussian Blur" background that fills the screen, making your video look high-quality and native to the platform.
How to resize video for Instagram & TikTok
- 1
Upload: Select your video file (MP4, MOV, etc).
- 2
Choose Format: Select 9:16 (TikTok), 4:5 (Instagram), or 1:1.
- 3
Export: Click download. The background is auto-filled with a blur effect.
Supported Aspect Ratios
- 9:16 (Vertical): Best for TikTok, Instagram Reels, YouTube Shorts.
- 4:5 (Portrait): Best for Instagram Feed posts.
- 1:1 (Square): Best for LinkedIn and Facebook.
- 16:9 (Landscape): Traditional YouTube format.