Flip Video

What Is the Flip Video Tool?

The Flip Video Tool lets you mirror video files horizontally, vertically, or in both directions directly in your browser. It uses FFmpeg WebAssembly (ffmpeg.wasm) to perform the video processing entirely on your device — no files are uploaded to any server. For flipping animated GIFs instead, use the Flip GIF tool.

When you select a video and choose a flip direction, the tool loads FFmpeg into your browser and applies the corresponding video filter. For a horizontal flip, it uses the hflip filter; for vertical, the vflip filter; and for both, it chains hflip,vflip together. The output is a new video file you can download.

How Video Flipping Works

Video flipping is a geometric transformation applied to each frame of the video. The tool uses the FFmpeg -vf (video filter) option with the appropriate flip filter:

• Horizontal Flip (hflip): Mirrors each frame left-to-right. Coordinates are transformed as $x' = W - x - 1$, where $W$ is the frame width and $x$ is the original pixel column.
• Vertical Flip (vflip): Mirrors each frame top-to-bottom. Coordinates are transformed as $y' = H - y - 1$, where $H$ is the frame height and $y$ is the original pixel row.
• Both (hflip,vflip): Applies both transformations sequentially, equivalent to a 180-degree rotation about the center.

FFmpeg processes the video with the -preset fast option for reasonable encoding speed while maintaining good quality. The output uses the same container format and codec as the original input.

Using the Flip Video Tool

On first use, the tool loads the FFmpeg WebAssembly engine from a CDN (about 30 MB). This happens once per session. After loading, select a video file from your device using the file input — any common video format is supported (MP4, AVI, MOV, WebM, etc.). Choose your flip direction and click "Flip Video". A progress bar shows the encoding progress. When complete, the flipped video appears with playback controls, and you can download it. For other video edits, try the Adjust Video Speed or Add Watermark to Video tools.

Processing time depends on the video length, resolution, codec, and your device's performance. Short videos (a few minutes at 1080p) typically process within seconds to a minute.

Privacy and Security

Because the Flip Video Tool runs ffmpeg.wasm entirely in your browser, your video files never leave your device. This is especially important for sensitive or personal videos that you do not want to upload to a third-party server. You can also Add or Replace Audio in Video with similar privacy guarantees.