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                <h2>1. Convert image data to base64 by image url</h2>
<input type="text" placeholder="image url" class="url">
<button class="convert">convert to base64</button>
  2. Convert image selected from local to base64;
<input type="file" accept="image/*" class="local" />

<h2>3.Convert clipboard's image data to base64;</h2>
<button class="clipboard">from clipboard</button>




                function convertImageToBase64(imgUrl, callback) {
  const image = new Image();
  image.onload = () => {
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    canvas.height = image.naturalHeight;
    canvas.width = image.naturalWidth;
    ctx.drawImage(image, 0, 0);
    const dataUrl = canvas.toDataURL();
    callback && callback(dataUrl)
  image.src = imgUrl;

document.querySelector(".convert").onclick = () => {
  const url = document.querySelector(".url").value;
  if (!url) {
    alert('please input image url')
  if (!url.startsWith('http')) {
    alert('invalid image url');
  convertImageToBase64(url, console.log);

const $file = document.querySelector(".local");
$file.addEventListener("change", (event) => {
    const selectedfile =;
    if (selectedfile.length > 0) {
      const [imageFile] = selectedfile;
      const fileReader = new FileReader();
      fileReader.onload = () => {
        const srcData = fileReader.result;
        console.log('base64:', srcData)

document.querySelector('.clipboard').onclick = async function parseClipboardImageData() {
  const items = await
  for (let item of items) {
    for (let type of item.types) {
      if (type.startsWith("image/")) {
        return item
          .then(blob => {
            return new Promise((resolve) => {
              const fileReader = new FileReader();
              fileReader.onload = () => {
                const srcData = fileReader.result;