Aspect Ratio

How to Use

1. Click the area above to select a file, or drag and drop a file onto the page
2. Adjust parameters in the settings area
3. Click the process button and download the result when ready

Frequently Asked Questions

How It Works

The Aspect Ratio tool uses FFmpeg WebAssembly with the pad, crop, and scale filters to adjust video dimensions to target aspect ratios. The tool supports both letterboxing (adding black bars) and cropping (removing content) approaches.

For black bar mode: The video is scaled to fit within the target aspect ratio while maintaining its original proportions. The remaining space is filled using FFmpeg's pad filter with a configurable color (default: black). For example, fitting a 16:9 video into 1:1 adds bars above and below.

For crop mode: The video is scaled to cover the target aspect ratio entirely, and excess content is cropped from the center (or edges). The scale+crop chain ensures the output exactly matches the target dimensions. The tool calculates optimal scale factors using the formula: scale=W:H:force_original_aspect_ratio=decrease for padding, or force_original_aspect_ratio=increase for cropping.

Tips & Best Practices

• Black bars for preserving content: Use padding when you need to show the entire frame — ideal for converting 16:9 to 1:1 for Instagram without losing anything.
• Crop for clean framing: Use crop mode when you can afford to lose edge content — results in a more natural-looking output.
• 9:16 for TikTok/Reels/Shorts: Converting landscape to vertical is the most common use — use black bars or crop based on where your subject is centered.
• 1:1 for Instagram feed: Square format works best for grid aesthetics — pad or crop to fit your content priority.
• Check after processing: Preview the result to ensure important content wasn't cropped out or obscured by bars.
• Custom ratios: For non-standard ratios, enter the exact pixel dimensions you need for precise output.

Use Cases

Social media managers reformatting landscape videos to 9:16 vertical for TikTok, Instagram Reels, and YouTube Shorts without losing key visual content.

Podcast producers converting widescreen interview recordings to 1:1 square format for audiogram-style social posts. Marketing teams adapting single-format video assets into multiple aspect ratios for cross-platform campaigns. Wedding videographers converting ceremony footage to different ratios for various delivery formats. News organizations adapting footage between horizontal broadcast and vertical mobile formats. Event planners preparing video content for different display configurations at venues.

Related Tools