How long is base64 url stored in local storage valid?

const scene = game.scene.getScene('default');
const canvas = scene.game.canvas;

// set size of the screenshot
const cropWidth = 350;
const cropHeight = 400;

// save the whole canvas as screenshot
const screenshotCanvas = document.createElement('canvas');
screenshotCanvas.width = canvas.width;
screenshotCanvas.height = canvas.height;

const context = screenshotCanvas.getContext('2d');
context.drawImage(canvas, 0, 0);

// crop center cropWidth x cropHeight area
const cropCanvas = document.createElement('canvas');
cropCanvas.width = cropWidth;
cropCanvas.height = cropHeight;

const cropContext = cropCanvas.getContext('2d');

// center cooridante
const sx = Math.round((canvas.width - cropWidth) / 2);
const sy = Math.round((canvas.height - cropHeight) / 2) - 50;
const sWidth = cropWidth;
const sHeight = cropHeight;

cropContext.drawImage(
  screenshotCanvas,
  sx,
  sy,
  sWidth,
  sHeight,
  0,
  0,
  cropWidth,
  cropHeight,
);

// Base64 convert
const base64 = cropCanvas.toDataURL('image/png');

// convert base64 to HTMLImageElement
const image = new Image();
image.src = base64;

// add as Phaser texture after being loaded
image.onload = () => {
  const index = localStorage.length + 1;
  scene.textures.addImage(`preset_${index}`, image);
  console.log(`Screenshot saved to cache as preset_${index}.`);

  // information will be stored in local storage
  const screenshotInfo = {
    index: index,
    data: base64,
    nameTag: nameTag,
    human: human,
    wing: wing,
    aura: aura,
    nickname: nickname,
  };

  // save in local storage
  localStorage.setItem(`preset_${index}`, JSON.stringify(screenshotInfo));

  // check saved data
  console.log('Saved image info:', screenshotInfo);
};

I use this code to save a screenshot of the phaser canvas in my local storage.

I could view the image by simply inserting the generated url into the browser link box.

But the problem is, I don’t know how long is this url valid.

Whether I clear the local storage or test it on a Incognito tab, the link was still valid.

Doesn’t this mean that the image information is being stored somewhere other than the local storage?

How can this link be expired?