How to paste files

Pasting files into the browser consists of using the paste event of the HTMLElement.

Using the HTMLElement's paste event

As a first step, you add an event listener for the paste event at the desired element, commonly this is at the document level, so no specific element needs to be focused. Next, you use the Clipboard API, which gives you access to the clipboardData field of the HTMLElement's paste event, whose files list you can then iterate over. Based on the MIME type of each of the files pasted, you can decide whether to render it to the screen, as in the case of an image or video, or to paste the text contents of the file into, for example, a textarea element, in the case of a text file.

{% BrowserCompat 'api.Clipboard' %}

document.addEventListener('paste', async (e) => {
  // Prevent the default behavior, so you can code your own logic.
  e.preventDefault();
  if (!e.clipboardData.files.length) {
    return;
  }
  // Iterate over all pasted files.
  Array.from(e.clipboardData.files).forEach(async (file) => {
    // Add more checks here for MIME types you're interested in,
    // such as `application/pdf`, `video/mp4`, etc.
    if (file.type.startsWith('image/')) {
      // For images, create an image and append it to the `body`.
      const img = document.createElement('img');
      const blob = URL.createObjectURL(file);
      img.src = blob;
      document.body.append(img);
    } else if (file.type.startsWith('text/')) {
      // For text files, read the contents and output it into a `textarea`.
      const textarea = document.createElement('textarea');
      textarea.value = await file.text();
      document.body.append(textarea);
    }
  });
});

Further reading

• Clipboard API
• Unblocking clipboard access

Demo