CODEWITHSUNDEEP
javascripthtmlimagebase64
Mario
Mario

Reputation: 2031

How to download a base64-encoded image?

I have a base64-encoded image from the server for which I want to force the download through JavaScript. Is is possible?

Upvotes: 111

Views: 278706

Answers (10)

Garande
Garande

Reputation: 192

I don't know whether am late to answer this, but I think the better solution could be this.

  1. Create a file from the base64string

    const convertBase64ToFile = (base64String, fileName) => {
     let arr = base64String.split(',');
     let mime = arr[0].match(/:(.*?);/)[1];
     let bstr = atob(arr[1]);
     let n = bstr.length;
     let uint8Array = new Uint8Array(n);
     while (n--) {
        uint8Array[n] = bstr.charCodeAt(n);
     }
     let file = new File([uint8Array], fileName, { type: mime });
     return file;
}

  2. Install File Saver from npm with

    npm install file-saver

  3. Import File Saver

    const { saveAs } = require('file-saver');
/// OR 
import { saveAs } from 'file-saver';

  4. Using File Saver download the file

    const downloadBase64Data = async (base64String, fileName) => {
     let file = convertBase64ToFile(base64String, fileName);
     await saveAs(file, fileName);
     return;
}

If this Answer has worked for you please upvote it and mark it as correct to help others easily find it

Upvotes: 9

Minko Gechev
Minko Gechev

Reputation: 25692

  1. If you want to download it using JavaScript (without any back-end) use:

    window.location.href = 'data:application/octet-stream;base64,' + img;

    where img is your base64 encoded image.

  2. If you want to allow the user to specify a file name, use the download attribute of the a tag:

    <a download="FILENAME.EXT" href="data:image/png;base64,asdasd...">Download</a>
    • Notice: The download attribute is not supported by very old browsers

Upvotes: 134

datta ambareesh
datta ambareesh

Reputation: 161

In my Angular App, I am getting the base 64 files from server.

In Html:-

<button type="button" (click)="downloadFile(fileName,base64data,fileType)"></button>

In Ts:-

  downloadFile(fileName:string,data: any,fileFormat:string): void {
    const linkSource = 'data:'+fileFormat+';base64'+data;
    const downloadLink = document.createElement("a");
    downloadLink.href = linkSource;
    downloadLink.download = fileName;
    downloadLink.click();
}

Upvotes: 8

Ehsan Ahmadi
Ehsan Ahmadi

Reputation: 1498

It is so simple just use function below: 

// Parameters:
// contentType: The content type of your file. 
//              its like application/pdf or application/msword or image/jpeg or
//              image/png and so on
// base64Data: Its your actual base64 data
// fileName: Its the file name of the file which will be downloaded. 

function downloadBase64File(contentType, base64Data, fileName) {
     const linkSource = `data:${contentType};base64,${base64Data}`;
     const downloadLink = document.createElement("a");
     downloadLink.href = linkSource;
     downloadLink.download = fileName;
     downloadLink.click();
}

Upvotes: 46

Sebastian
Sebastian

Reputation: 2944

At first: This question is extremly browser dependent! I tried many, so I came up to answer this question that way:

You should put the base64-Data inside the src-Tag of an IMG-Element: How to display Base64 images in HTML? Then you can right click the Image and click "Save Image..." (or similar) in these browsers:

  • Chrome 79
  • Edge 44
  • Firefox 71
  • IE 11
  • Safari 13

Also on Android with Chrome and Firefox. Biggest file working was 23 MB PNG-File in IE 11 and Safari 13. But Firefox and Chrome did also work for 86 MB JPEG.

Upvotes: 0

Daniel Brooks
Daniel Brooks

Reputation: 1087

Simple way to do this with Javascript...

    var a = document.createElement("a"); //Create <a>
    a.href = "data:image/png;base64," + ImageBase64; //Image Base64 Goes here
    a.download = "Image.png"; //File name Here
    a.click(); //Downloaded file

Upvotes: 106

Piyush Thawakar
Piyush Thawakar

Reputation: 71

In my React App, I was getting the base 64 images from an API, I stored it in a global prop and downloaded it with the help of <a> tag.

<a href={`data:application/octet-stream;base64,${this.props.base64image}`} download={"imageName"}>Click to Download the image</a>

Upvotes: 3

Sentient
Sentient

Reputation: 851

I found this solution from the sourcecode of how Chrome takes full-page screenshots.

const base64string = "";
const pageImage = new Image();
pageImage.src = 'data:image/png;base64,' + base64string;
pageImage.onload = function() {
    const canvas = document.createElement('canvas');
    canvas.width = pageImage.naturalWidth;
    canvas.height= pageImage.naturalHeight;

    const ctx = canvas.getContext('2d');
    ctx.imageSmoothingEnabled = false;
    ctx.drawImage(pageImage, 0, 0);
    console.log(canvas, pageImage)
    saveScreenshot(canvas);
}
function saveScreenshot(canvas) {
    let fileName = "image"
    const link = document.createElement('a');
    link.download = fileName + '.png';
    console.log(canvas)
    canvas.toBlob(function(blob) {
        console.log(blob)
        link.href = URL.createObjectURL(blob);
        link.click();
    });
};

Upvotes: 12

cweitat
cweitat

Reputation: 1257

If you already have it in base64, add the image tag in front of the base64. attach it to the element 

png64 = "data:image/" + png64; 
$('#downloadPNG').attr('href', png64);

Add the file name that you want when downloading to the download tag.

<a download="chart.png" id="downloadPNG">Export img</a>

Upvotes: 2

Amit Gandole
Amit Gandole

Reputation: 576

You can try this : 

    <!doctype html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Download Text File DataURL Demo</title>
        <style>
            body{ font: menu; }
        </style>
        <script src='//js.zapjs.com/js/download.js'></script>
    </head>
    <body>
        <h1>Download Text File DataURL Demo</h1>
        <main></main>
        <script>
            download("data:application/octet-stream;base64,YOUR BASE64URL", "dlDataUrlText.jpeg", "application/octet-stream;base64");
        </script>
    </body>

</html>

download tag downloads the image using the script included.

For reference you can try this URL : http://danml.com/download.html

Upvotes: 7

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