> ## Documentation Index
> Fetch the complete documentation index at: https://vidow.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Merge Videos — Combine Multiple Video Files into One

> Join multiple video files into a single continuous video. Drag to reorder, then merge — all processing happens locally in your browser.

<Info>The video merger is a **Professional** feature. [Upgrade your plan](/billing/plans) to access it.</Info>

The Video Downloader Plus video merger combines multiple video files into a single continuous output. Add your files, drag to set the order, choose an output format, and merge — everything runs locally in your browser.

## How to merge videos

<Steps>
  <Step title="Open the tool">
    Go to [vidow.io/tools/merge](https://vidow.io/tools/merge).
  </Step>

  <Step title="Add video files">
    Click **Add videos** and select multiple files, or drag them onto the page. You can add files from multiple sources.
  </Step>

  <Step title="Drag to reorder">
    Drag the video clips into the order they should appear in the final output.
  </Step>

  <Step title="Choose output format">
    Select your preferred output container format.
  </Step>

  <Step title="Merge">
    Click **Merge**. Processing runs entirely in your browser — no data is uploaded.
  </Step>

  <Step title="Download">
    Download the merged video file when processing is complete.
  </Step>
</Steps>

## Supported formats

|            | Formats        |
| ---------- | -------------- |
| **Input**  | MP4, WebM, MKV |
| **Output** | MP4, WebM, MKV |

## Notes on compatibility

For best results, input files should share the same codec, resolution, and frame rate. When the tool detects incompatible files, it re-encodes them to a common format before merging — this takes longer but always produces a valid output.

## How it works

Merging runs locally in your browser using a WebAssembly build of FFmpeg. When input files are compatible, the merger concatenates them directly without re-encoding for fast, lossless results. Re-encoding is applied automatically when needed. No data is sent to any server.

## Related tools

<CardGroup cols={3}>
  <Card title="Video Trimmer" href="/tools/video-trimmer">
    Trim individual clips before merging them.
  </Card>

  <Card title="Add Audio" href="/tools/add-audio">
    Add a background track or narration to the merged video.
  </Card>

  <Card title="Video Compressor" href="/tools/video-compressor">
    Reduce the file size of the merged output.
  </Card>
</CardGroup>