Letterbox / Pillarbox
Fit a video to a target aspect ratio (16:9, 9:16, 1:1, 4:3) with black bars — no cropping.
About Letterbox / Pillarbox
Letterbox / Pillarbox fits a video into a target aspect ratio — 16:9, 9:16, 1:1, or 4:3 — by adding black bars instead of cropping, so nothing in the frame is lost. It's the safe way to make a clip fit a platform that demands a specific shape, like a square feed post or a vertical story. The output is an MP4 and it all happens in your browser.
- Category
- media
- Input
- Accepts: video/*.
- Output
- Outputs: video/mp4.
- Cost
- Free, runs in your browser
- Memory
- high
- Install group
- ffmpeg
Common uses
- Fit a landscape video into a 9:16 vertical frame for Stories or Reels without cropping the subject
- Pad a widescreen clip to 1:1 square for a feed post that requires it
- Convert vertical phone footage to 16:9 with pillarbox bars for a YouTube upload
- Standardize a batch of mismatched clips to a single 4:3 ratio before editing them together
- Keep an entire wide shot visible on a square display by letterboxing the top and bottom
- Prepare a clip for an ad slot that mandates a fixed aspect ratio while preserving the full composition
Frequently asked questions
Does it crop my video?
No — that's the point. It pads with black bars to reach the target ratio so the whole frame stays visible.
Which aspect ratios can I target?
16:9, 9:16, 1:1, and 4:3.
What's the difference between letterbox and pillarbox?
Letterbox adds bars on the top and bottom (fitting wide content into a taller frame); pillarbox adds bars on the sides (fitting tall content into a wider frame). The tool picks whichever your target ratio requires.
What format does it export?
An MP4 video.
Is the video uploaded for processing?
No. The padding is applied in your browser and the file stays on your device.
Keywords
- video
- letterbox
- pillarbox
- aspect ratio
- bars
- pad
- reframe
- square
- vertical