Example using PDF.js

pdf.js

import range from 'lodash/range'

import('pdfjs/dist').then(pdfjs => {
  pdfjs
    .getDocument('wibble.pdf')
    .then(pdf => {
      const pagePromises = range(1, pdf.numPages).map(number => pdf.getPage(number))
      return Promise.all(pagePromises)
    })
    .then(
      pages => {
        const scale = 1.5

        const canvases = pages.map(page => {
          const viewport = page.getViewport(scale)

          // Prepare canvas using PDF page dimensions
          const canvas = document.createElement('canvas')
          canvas.height = viewport.height
          canvas.width = viewport.width

          // Render PDF page into canvas context
          const canvasContext = canvas.getContext('2d')
          const renderContext = { canvasContext, viewport }
          page.render(renderContext).then(() => console.log('Page rendered'))

          return canvas
        })

        canvases.forEach(canvas => document.body.appendChild(canvas))
      },
      error => console.log('Error', error),
    )
})