Convert SVG to image (JPEG, PNG, etc.) in the browser

Question

I want to convert SVG into bitmap images (like JPEG, PNG, etc.) through JavaScript.

Answer 1

Typescript mix of the @klues and @Nitsan BenHanoch anwswers to converts an svg string into a data:image/png;base64 string keeping the aspect ratio

/**
 * Converts an svg string into a data:image/png;base64 string keeping the aspect ratio
 */
function svgStringToBase64Png(
  svg: string,
  width: number = 1500,
): Promise<string | null> {
  const svgUrl = `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`
  return new Promise<string | null>((resolve) => {
    const img = document.createElement('img')
    img.onload = function () {
      document.body.appendChild(img)
      const canvas = document.createElement('canvas')
      const ratio = img.clientWidth / img.clientHeight || 1
      document.body.removeChild(img)
      canvas.width = width
      canvas.height = width / ratio
      const ctx = canvas.getContext('2d')
      ctx?.drawImage(img, 0, 0, canvas.width, canvas.height)
      try {
        const data = canvas.toDataURL('image/png')
        resolve(data)
      } catch (e) {
        resolve(null)
      }
    }
    img.onerror = function () {
      resolve(null)
    }
    img.src = svgUrl
  })
}

Answer 2

A modern-day async function to convert svg -> png:

/**
 * Converts an svg string into a data:image/png;base64 string.
 * @param {string} svg
 * @param {number | undefined} width
 * @param {number | undefined} height
 */
async function svg2png(svg, width = 1000, height = 1000) {
  const img = new Image();
  img.src = `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`;

  await new Promise((resolve, reject) => {
    img.onload = resolve;
    img.onerror = reject;
  });

  const canvas = document.createElement("canvas");
  [canvas.width, canvas.height] = [width, height];

  const ctx = canvas.getContext("2d");
  ctx.drawImage(img, 0, 0, width, height);

  return canvas.toDataURL("image/png");
}

Answer 3

This is an old question, in 2022 we have ES6 and we don't need 3rd party libraries.

Here is a very basic way to convert svg images into other formats.

The trick is to load the svg element as an img element, then use a canvas element to convert the image into the desired format. So, four steps are needed:

1. Extract svg as xml data string.
2. Load the xml data string into a img element
3. Convert the img element to a dataURL using a canvas element
4. Load the converted dataURL into a new img element

Step 1

Extracting a svg as xml data string is simple, we don't need to convert it as a base64 string. We just serialize it as XML then we encode the string as a URI:

// Data header for a svg image: 
const dataHeader = 'data:image/svg+xml;charset=utf-8'

// Serialize it as xml string:
const serializeAsXML = $e => (new XMLSerializer()).serializeToString($e)

// Encode URI data as UTF8 data:
const encodeAsUTF8 = s => `${dataHeader},${encodeURIComponent(s)}`

// Select the element:
const $svg = document.getElementById('svg-container').querySelector('svg')

// Encode it as a data string:
const svgData = encodeAsUTF8(serializeAsXML($svg))

Note:

If you need a base64 data you can use this option:

...

// Encode URI data as base64 data:
const encodeAsB64 = s => `${dataHeader};base64,${btoa(s)}`
...

// Encode it as a data string:
const svgData = encodeAsB64(serializeAsXML($svg))

Step 2

Loading the xml data string into a img element:

// This function returns a Promise whenever the $img is loaded
const loadImage = async url => {
    const $img = document.createElement('img')
    $img.src = url
    return new Promise((resolve, reject) => {
        $img.onload = () => resolve($img)
        $img.onerror = reject
        $img.src = url
    })
}

Step 3

Converting the img element to a dataURL using a canvas element:

const $canvas = document.createElement('canvas')
$canvas.width = $svg.clientWidth
$canvas.height = $svg.clientHeight
$canvas.getContext('2d').drawImage(img, 0, 0, $svg.clientWidth, $svg.clientHeight)
return $canvas.toDataURL(`image/${format}`, 1.0)

Step 4

Loading the converted dataURL into a new img element:

const $img = document.createElement('img')
$img.src = dataURL
$holder.appendChild($img)

Here you have a working snippet:

const dataHeader = 'data:image/svg+xml;charset=utf-8'
const $svg = document.getElementById('svg-container').querySelector('svg')
const $holder = document.getElementById('img-container')
const $label = document.getElementById('img-format')

const destroyChildren = $element => {
  while ($element.firstChild) {
    const $lastChild = $element.lastChild ?? false
    if ($lastChild) $element.removeChild($lastChild)
  }
}

const loadImage = async url => {
  const $img = document.createElement('img')
  $img.src = url
  return new Promise((resolve, reject) => {
    $img.onload = () => resolve($img)
    $img.onerror = reject
  })
}

const serializeAsXML = $e => (new XMLSerializer()).serializeToString($e)

const encodeAsUTF8 = s => `${dataHeader},${encodeURIComponent(s)}`
const encodeAsB64 = s => `${dataHeader};base64,${btoa(s)}`

const convertSVGtoImg = async e => {
  const $btn = e.target
  const format = $btn.dataset.format ?? 'png'
  $label.textContent = format

  destroyChildren($holder)

  const svgData = encodeAsUTF8(serializeAsXML($svg))

  const img = await loadImage(svgData)
  
  const $canvas = document.createElement('canvas')
  $canvas.width = $svg.clientWidth
  $canvas.height = $svg.clientHeight
  $canvas.getContext('2d').drawImage(img, 0, 0, $svg.clientWidth, $svg.clientHeight)
  
  const dataURL = await $canvas.toDataURL(`image/${format}`, 1.0)
  console.log(dataURL)
  
  const $img = document.createElement('img')
  $img.src = dataURL
  $holder.appendChild($img)
}

const buttons = [...document.querySelectorAll('[data-format]')]
for (const $btn of buttons) {
  $btn.onclick = convertSVGtoImg
}

.wrapper {
  display: flex;
  flex-flow: row nowrap;
  width: 100vw;
}

.images {
  display: flex;
  flex-flow: row nowrap;
  width: 70%;
}

.image {
  width: 50%;
  display: flex;
  flex-flow: row wrap;
  justify-content: center;
}

.label {
  width: 100%;
  text-align: center;
}

<div class="wrapper">
  <div class="item images">
    <div class="image left">
      <div class="label">svg</div>
      <div id="svg-container">
        <svg xmlns="http://www.w3.org/2000/svg" xml:space="preserve" width="200" height="200" viewBox="0 0 248 204">
  <path fill="#1d9bf0" d="M221.95 51.29c.15 2.17.15 4.34.15 6.53 0 66.73-50.8 143.69-143.69 143.69v-.04c-27.44.04-54.31-7.82-77.41-22.64 3.99.48 8 .72 12.02.73 22.74.02 44.83-7.61 62.72-21.66-21.61-.41-40.56-14.5-47.18-35.07 7.57 1.46 15.37 1.16 22.8-.87-23.56-4.76-40.51-25.46-40.51-49.5v-.64c7.02 3.91 14.88 6.08 22.92 6.32C11.58 63.31 4.74 33.79 18.14 10.71c25.64 31.55 63.47 50.73 104.08 52.76-4.07-17.54 1.49-35.92 14.61-48.25 20.34-19.12 52.33-18.14 71.45 2.19 11.31-2.23 22.15-6.38 32.07-12.26-3.77 11.69-11.66 21.62-22.2 27.93 10.01-1.18 19.79-3.86 29-7.95-6.78 10.16-15.32 19.01-25.2 26.16z"/>
</svg>
      </div>
    </div>
    <div class="image right">
      <div id="img-format" class="label"></div>
      <div id="img-container"></div>
    </div>
  </div>
  <div class="item buttons">
    <button id="btn-png" data-format="png">PNG</button>
    <button id="btn-jpg" data-format="jpeg">JPG</button>
    <button id="btn-webp" data-format="webp">WEBP</button>
  </div>
</div>

Answer 4

Here are my 2 cents. Somehow Download anchor tag is not working as expected in code snippet, however it was working fine in Chrome.

Here is working jsFiddle

const waitForImage = imgElem => new Promise(resolve => imgElem.complete ? resolve() : imgElem.onload = imgElem.onerror = resolve);

const svgToImgDownload = ext => {
  if (!['png', 'jpg', 'webp'].includes(ext))
    return;
  const _svg = document.querySelector("#svg_container").querySelector('svg');
  const xmlSerializer = new XMLSerializer();
  let _svgStr = xmlSerializer.serializeToString(_svg);
  const img = document.createElement('img');
  img.src = 'data:image/svg+xml;base64,' + window.btoa(_svgStr);
  waitForImage(img)
    .then(_ => {
      const canvas = document.createElement('canvas');
      canvas.width = _svg.clientWidth;
      canvas.height = _svg.clientHeight;
      canvas.getContext('2d').drawImage(img, 0, 0, _svg.clientWidth, _svg.clientHeight);
      return canvas.toDataURL('image/' + (ext == 'jpg' ? 'jpeg' : ext), 1.0);
    })
    .then(dataURL => {
      console.log(dataURL);
      document.querySelector("#img_download_btn").innerHTML = `<a href="${dataURL}" download="img.${ext}">Download</a>`;
    })
    .catch(console.error);
};

document.querySelector('#map2Png').addEventListener('click', _ => svgToImgDownload('png'));
document.querySelector('#map2Jpg').addEventListener('click', _ => svgToImgDownload('jpg'));
document.querySelector('#map2Webp').addEventListener('click', _ => svgToImgDownload('webp'));

<div id="svg_container" style="float: left; width: 50%">
  <svg width="200" height="200" viewBox="-100 -100 200 200">
    <circle cx="0" cy="20" r="70" fill="#D1495B" />
    <circle cx="0" cy="-75" r="12" fill="none" stroke="#F79257" stroke-width="2" />
    <rect x="-17.5" y="-65" width="35" height="20" fill="#F79257" />
  </svg>
</div>

<div>
  <button id="map2Png">PNG</button>
  <button id="map2Jpg">JPG</button>
  <button id="map2Webp">WEBP</button>
</div>

<div id="img_download_btn"></div>

Answer 5

1. get data URIs from SVG:

   data:image/svg+xml;base64,${btoa(new XMLSerializer().serializeToString(svgElem))}

2. prepare an Image
3. create a canvas and use toDataURL to export.

Example

<!-- test data-->
<svg width="400" height="400"><g transform="translate(23.915343915343925,-80.03971756398937)" class="glyph" stroke="#000000" fill="#a0a0a0"><path d="M74.97 108.70L74.97 108.70L100.08 110.77Q93.89 147.91 87.35 179.89L87.35 179.89L148.23 179.89L148.23 194.34Q143.76 277.91 113.84 339.81L113.84 339.81Q144.44 363.54 163.70 382.46L163.70 382.46L146.51 402.75Q128.62 384.18 101.80 361.83L101.80 361.83Q75.32 405.85 34.39 436.80L34.39 436.80L17.20 415.82Q57.43 386.93 82.20 345.66L82.20 345.66Q57.78 326.40 27.86 304.39L27.86 304.39Q44.37 257.96 56.75 203.97L56.75 203.97L19.26 203.97L19.26 179.89L61.90 179.89Q69.47 145.16 74.97 108.70ZM93.20 323.99L93.20 323.99Q118.65 272.06 123.12 203.97L123.12 203.97L82.20 203.97Q69.47 260.03 55.71 297.17L55.71 297.17Q76.01 311.61 93.20 323.99ZM160.26 285.13L160.26 260.37L239.71 260.37L239.71 216.01Q268.25 191.24 294.05 155.48L294.05 155.48L170.58 155.48L170.58 130.71L322.94 130.71L322.94 155.48Q297.49 191.93 265.50 223.92L265.50 223.92L265.50 260.37L337.38 260.37L337.38 285.13L265.50 285.13L265.50 397.59Q265.50 431.64 237.65 431.64L237.65 431.64L187.09 431.64L180.21 407.57Q202.22 407.91 227.67 407.91L227.67 407.91Q239.71 407.91 239.71 390.03L239.71 390.03L239.71 285.13L160.26 285.13Z"></path></g></svg>

<button title="download">svg2png</button>
<script>
    const output = {"name": "result.png", "width": 64, "height": 64}
    document.querySelector("button").onclick = () => {
        const svgElem = document.querySelector("svg")
        // const uriData = `data:image/svg+xml;base64,${btoa(svgElem.outerHTML)}` // it may fail.
        const uriData = `data:image/svg+xml;base64,${btoa(new XMLSerializer().serializeToString(svgElem))}`
        const img = new Image()
        img.src = uriData
        img.onload = () => {
            const canvas = document.createElement("canvas");
            [canvas.width, canvas.height] = [output.width, output.height]
            const ctx = canvas.getContext("2d")
            ctx.drawImage(img, 0, 0, output.width, output.height)

            // 👇 download
            const a = document.createElement("a")
            const quality = 1.0 // https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/imageSmoothingQuality
            a.href = canvas.toDataURL("image/png", quality)
            a.download = output.name
            a.append(canvas)
            a.click()
            a.remove()
        }
    }
</script>

Answer 6

Here a function that works without libraries and returns a Promise:

/**
 * converts a base64 encoded data url SVG image to a PNG image
 * @param originalBase64 data url of svg image
 * @param width target width in pixel of PNG image
 * @return {Promise<String>} resolves to png data url of the image
 */
function base64SvgToBase64Png (originalBase64, width) {
    return new Promise(resolve => {
        let img = document.createElement('img');
        img.onload = function () {
            document.body.appendChild(img);
            let canvas = document.createElement("canvas");
            let ratio = (img.clientWidth / img.clientHeight) || 1;
            document.body.removeChild(img);
            canvas.width = width;
            canvas.height = width / ratio;
            let ctx = canvas.getContext("2d");
            ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
            try {
                let data = canvas.toDataURL('image/png');
                resolve(data);
            } catch (e) {
                resolve(null);
            }
        };
        img.onerror = function() {
            resolve(null);
        };
        img.src = originalBase64;
    });
}

On Firefox there is an issue for SVGs without set width / height.

See this working example including a fix for the Firefox issue.

Answer 7

My use case was to have the svg data loaded from a network and this ES6 Class did the Job.

class SvgToPngConverter {
  constructor() {
    this._init = this._init.bind(this);
    this._cleanUp = this._cleanUp.bind(this);
    this.convertFromInput = this.convertFromInput.bind(this);
  }

  _init() {
    this.canvas = document.createElement("canvas");
    this.imgPreview = document.createElement("img");
    this.imgPreview.style = "position: absolute; top: -9999px";

    document.body.appendChild(this.imgPreview);
    this.canvasCtx = this.canvas.getContext("2d");
  }

  _cleanUp() {
    document.body.removeChild(this.imgPreview);
  }

  convertFromInput(input, callback) {
    this._init();
    let _this = this;
    this.imgPreview.onload = function() {
      const img = new Image();
      _this.canvas.width = _this.imgPreview.clientWidth;
      _this.canvas.height = _this.imgPreview.clientHeight;
      img.crossOrigin = "anonymous";
      img.src = _this.imgPreview.src;
      img.onload = function() {
        _this.canvasCtx.drawImage(img, 0, 0);
        let imgData = _this.canvas.toDataURL("image/png");
        if(typeof callback == "function"){
            callback(imgData)
        }
        _this._cleanUp();
      };
    };

    this.imgPreview.src = input;
  }
}

Here is how you use it

let input = "https://restcountries.eu/data/afg.svg"
new SvgToPngConverter().convertFromInput(input, function(imgData){
    // You now have your png data in base64 (imgData). 
    // Do what ever you wish with it here.
});

If you want a vanilla JavaScript version, you could head over to Babel website and transpile the code there.

Answer 8

There are several ways to convert SVG to PNG using the Canvg library.

In my case, I needed to get the PNG blob from inline SVG.

The library documentation provides an example (see OffscreenCanvas example).

But this method does not work at the moment in Firefox. Yes, you can enable the gfx.offscreencanvas.enabled option in the settings. But will every user on the site do this? :)

However, there is another way that will work in Firefox too.

const el = document.getElementById("some-svg"); //this is our inline SVG

var canvas = document.createElement('canvas'); //create a canvas for the SVG render
canvas.width = el.clientWidth; //set canvas sizes
canvas.height = el.clientHeight;

const svg = new XMLSerializer().serializeToString(el); //convert SVG to string

//render SVG inside canvas
const ctx = canvas.getContext('2d');
const v = await Canvg.fromString(ctx, svg);
await v.render();

let canvasBlob = await new Promise(resolve => canvas.toBlob(resolve));

For the last line thanks to this answer

Answer 9

Svg to png can be converted depending on conditions:

1. If svg is in format SVG (string) paths:

• create canvas
• create new Path2D() and set svg as parameter
• draw path on canvas
• create image and use canvas.toDataURL() as src.

example:

const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
let svgText = 'M10 10 h 80 v 80 h -80 Z';
let p = new Path2D('M10 10 h 80 v 80 h -80 Z');
ctx.stroke(p);
let url = canvas.toDataURL();
const img = new Image();
img.src = url;

Note that Path2D not supported in ie and partially supported in edge. Polyfill solves that: https://github.com/nilzona/path2d-polyfill

2. Create svg blob and draw on canvas using .drawImage():

• make canvas element
• make a svgBlob object from the svg xml
• make a url object from domUrl.createObjectURL(svgBlob);
• create an Image object and assign url to image src
• draw image into canvas
• get png data string from canvas: canvas.toDataURL();

Nice description: https://web.archive.org/web/20200125162931/http://ramblings.mcpher.com:80/Home/excelquirks/gassnips/svgtopng

Note that in ie you will get exception on stage of canvas.toDataURL(); It is because IE has too high security restriction and treats canvas as readonly after drawing image there. All other browsers restrict only if image is cross origin.

3. Use canvg JavaScript library. It is separate library but has useful functions.

Like:

ctx.drawSvg(rawSvg);
var dataURL = canvas.toDataURL();

Answer 10

The solution to convert SVG to blob URL and blob URL to png image

const svg=`<svg version="1.1" baseProfile="full" width="300" height="200"
xmlns="http://www.w3.org/2000/svg">
   <rect width="100%" height="100%" fill="red" />
   <circle cx="150" cy="100" r="80" fill="green" />
   <text x="150" y="125" font-size="60" text-anchor="middle" fill="white">SVG</text></svg>`
svgToPng(svg,(imgData)=>{
    const pngImage = document.createElement('img');
    document.body.appendChild(pngImage);
    pngImage.src=imgData;
});
 function svgToPng(svg, callback) {
    const url = getSvgUrl(svg);
    svgUrlToPng(url, (imgData) => {
        callback(imgData);
        URL.revokeObjectURL(url);
    });
}
function getSvgUrl(svg) {
    return  URL.createObjectURL(new Blob([svg], { type: 'image/svg+xml' }));
}
function svgUrlToPng(svgUrl, callback) {
    const svgImage = document.createElement('img');
    // imgPreview.style.position = 'absolute';
    // imgPreview.style.top = '-9999px';
    document.body.appendChild(svgImage);
    svgImage.onload = function () {
        const canvas = document.createElement('canvas');
        canvas.width = svgImage.clientWidth;
        canvas.height = svgImage.clientHeight;
        const canvasCtx = canvas.getContext('2d');
        canvasCtx.drawImage(svgImage, 0, 0);
        const imgData = canvas.toDataURL('image/png');
        callback(imgData);
        // document.body.removeChild(imgPreview);
    };
    svgImage.src = svgUrl;
 }

Answer 11

I recently discovered a couple of image tracing libraries for JavaScript that indeed are able to build an acceptable approximation to the bitmap, both size and quality. I'm developing this JavaScript library and CLI :

https://www.npmjs.com/package/svg-png-converter

Which provides unified API for all of them, supporting browser and node, non depending on DOM, and a Command line tool.

For converting logos/cartoon/like images it does excellent job. For photos / realism some tweaking is needed since the output size can grow a lot.

It has a playground although right now I'm working on a better one, easier to use, since more features has been added:

https://cancerberosgx.github.io/demos/svg-png-converter/playground/#

Answer 12

change svg to match your element

function svg2img(){
    var svg = document.querySelector('svg');
    var xml = new XMLSerializer().serializeToString(svg);
    var svg64 = btoa(xml); //for utf8: btoa(unescape(encodeURIComponent(xml)))
    var b64start = 'data:image/svg+xml;base64,';
    var image64 = b64start + svg64;
    return image64;
};svg2img()

Answer 13

This seems to work in most browsers:

function copyStylesInline(destinationNode, sourceNode) {
   var containerElements = ["svg","g"];
   for (var cd = 0; cd < destinationNode.childNodes.length; cd++) {
       var child = destinationNode.childNodes[cd];
       if (containerElements.indexOf(child.tagName) != -1) {
            copyStylesInline(child, sourceNode.childNodes[cd]);
            continue;
       }
       var style = sourceNode.childNodes[cd].currentStyle || window.getComputedStyle(sourceNode.childNodes[cd]);
       if (style == "undefined" || style == null) continue;
       for (var st = 0; st < style.length; st++){
            child.style.setProperty(style[st], style.getPropertyValue(style[st]));
       }
   }
}

function triggerDownload (imgURI, fileName) {
  var evt = new MouseEvent("click", {
    view: window,
    bubbles: false,
    cancelable: true
  });
  var a = document.createElement("a");
  a.setAttribute("download", fileName);
  a.setAttribute("href", imgURI);
  a.setAttribute("target", '_blank');
  a.dispatchEvent(evt);
}

function downloadSvg(svg, fileName) {
  var copy = svg.cloneNode(true);
  copyStylesInline(copy, svg);
  var canvas = document.createElement("canvas");
  var bbox = svg.getBBox();
  canvas.width = bbox.width;
  canvas.height = bbox.height;
  var ctx = canvas.getContext("2d");
  ctx.clearRect(0, 0, bbox.width, bbox.height);
  var data = (new XMLSerializer()).serializeToString(copy);
  var DOMURL = window.URL || window.webkitURL || window;
  var img = new Image();
  var svgBlob = new Blob([data], {type: "image/svg+xml;charset=utf-8"});
  var url = DOMURL.createObjectURL(svgBlob);
  img.onload = function () {
    ctx.drawImage(img, 0, 0);
    DOMURL.revokeObjectURL(url);
    if (typeof navigator !== "undefined" && navigator.msSaveOrOpenBlob)
    {
        var blob = canvas.msToBlob();         
        navigator.msSaveOrOpenBlob(blob, fileName);
    } 
    else {
        var imgURI = canvas
            .toDataURL("image/png")
            .replace("image/png", "image/octet-stream");
        triggerDownload(imgURI, fileName);
    }
    document.removeChild(canvas);
  };
  img.src = url;
}

Answer 14

Here is how you can do it through JavaScript:

1. Use the canvg JavaScript library to render the SVG image using Canvas: https://github.com/gabelerner/canvg
2. Capture a data URI encoded as a JPG (or PNG) from the Canvas, according to these instructions: Capture HTML Canvas as gif/jpg/png/pdf?

Answer 15

jbeard4 solution worked beautifully.

I'm using Raphael SketchPad to create an SVG. Link to the files in step 1.

For a Save button (id of svg is "editor", id of canvas is "canvas"):

$("#editor_save").click(function() {

// the canvg call that takes the svg xml and converts it to a canvas
canvg('canvas', $("#editor").html());

// the canvas calls to output a png
var canvas = document.getElementById("canvas");
var img = canvas.toDataURL("image/png");
// do what you want with the base64, write to screen, post to server, etc...
});