# blueimp-canvas-to-blob

> Canvas to Blob is a polyfill for the standard JavaScript canvas.toBlob method. It can be used to create Blob objects from an HTML canvas element.

Latest version **3.29.0** (published 2021-09-25) · MIT license · 0 weekly downloads

## Install

```sh
npm install blueimp-canvas-to-blob
pnpm add blueimp-canvas-to-blob
yarn add blueimp-canvas-to-blob
bun add blueimp-canvas-to-blob
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 3.29.0 |
| Published | 2021-09-25 |
| First published | 2012-02-11 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 14.3 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 1470 |
| Author | Sebastian Tschan |
| Maintainers | blueimp |
| Keywords | javascript, canvas, blob, convert, conversion |

## Links

- npm: https://www.npmjs.com/package/blueimp-canvas-to-blob
- Repository: https://github.com/blueimp/JavaScript-Canvas-to-Blob
- Issues: https://github.com/blueimp/JavaScript-Canvas-to-Blob/issues
- npm.io page: https://npm.io/package/blueimp-canvas-to-blob

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## Recent versions

- 3.29.0 (latest) — 2021-09-25
- 3.28.0 — 2020-07-26
- 3.27.0 — 2020-05-13
- 3.26.0 — 2020-05-10
- 3.25.0 — 2020-05-07
- 3.24.0 — 2020-05-04
- 3.23.0 — 2020-05-03
- 3.22.0 — 2020-04-30
- 3.21.0 — 2020-04-29
- 3.20.0 — 2020-04-18
- 3.19.0 — 2020-04-11
- 3.18.0 — 2020-03-26
- 3.17.0 — 2019-12-22
- 3.16.0 — 2019-08-27
- 3.15.0 — 2019-07-15
- … 34 more at https://npm.io/package/blueimp-canvas-to-blob/versions

## README

# JavaScript Canvas to Blob

## Contents

- [Description](#description)
- [Setup](#setup)
- [Usage](#usage)
- [Requirements](#requirements)
- [Browsers](#browsers)
- [API](#api)
- [Test](#test)
- [License](#license)

## Description

Canvas to Blob is a
[polyfill](https://developer.mozilla.org/en-US/docs/Glossary/Polyfill) for
Browsers that don't support the standard JavaScript
[HTMLCanvasElement.toBlob](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toBlob)
method.

It can be used to create
[Blob](https://developer.mozilla.org/en-US/docs/Web/API/Blob) objects from an
HTML [canvas](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/canvas)
element.

## Setup

Install via [NPM](https://www.npmjs.com/package/blueimp-canvas-to-blob):

```sh
npm install blueimp-canvas-to-blob
```

This will install the JavaScript files inside
`./node_modules/blueimp-canvas-to-blob/js/` relative to your current directory,
from where you can copy them into a folder that is served by your web server.

Next include the minified JavaScript Canvas to Blob script in your HTML markup:

```html
<script src="js/canvas-to-blob.min.js"></script>
```

Or alternatively, include the non-minified version:

```html
<script src="js/canvas-to-blob.js"></script>
```

## Usage

You can use the `canvas.toBlob()` method in the same way as the native
implementation:

```js
var canvas = document.createElement('canvas')
// Edit the canvas ...
if (canvas.toBlob) {
  canvas.toBlob(function (blob) {
    // Do something with the blob object,
    // e.g. create multipart form data for file uploads:
    var formData = new FormData()
    formData.append('file', blob, 'image.jpg')
    // ...
  }, 'image/jpeg')
}
```

## Requirements

The JavaScript Canvas to Blob function has zero dependencies.

However, it is a very suitable complement to the
[JavaScript Load Image](https://github.com/blueimp/JavaScript-Load-Image)
function.

## Browsers

The following browsers have native support for
[HTMLCanvasElement.toBlob](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toBlob):

- Chrome 50+
- Firefox 19+
- Safari 11+
- Mobile Chrome 50+ (Android)
- Mobile Firefox 4+ (Android)
- Mobile Safari 11+ (iOS)
- Edge 79+

Browsers which implement the following APIs support `canvas.toBlob()` via
polyfill:

- [HTMLCanvasElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement)
- [HTMLCanvasElement.toDataURL](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toDataURL)
- [Blob() constructor](https://developer.mozilla.org/en-US/docs/Web/API/Blob/Blob)
- [atob](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/atob)
- [ArrayBuffer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer)
- [Uint8Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array)

This includes the following browsers:

- Chrome 20+
- Firefox 13+
- Safari 8+
- Mobile Chrome 25+ (Android)
- Mobile Firefox 14+ (Android)
- Mobile Safari 8+ (iOS)
- Edge 74+
- Edge Legacy 12+
- Internet Explorer 10+

## API

In addition to the `canvas.toBlob()` polyfill, the JavaScript Canvas to Blob
script exposes its helper function `dataURLtoBlob(url)`:

```js
// Uncomment the following line when using a module loader like webpack:
// var dataURLtoBlob = require('blueimp-canvas-to-blob')

// black+white 3x2 GIF, base64 data:
var b64 = 'R0lGODdhAwACAPEAAAAAAP///yZFySZFySH5BAEAAAIALAAAAAADAAIAAAIDRAJZADs='
var url = 'data:image/gif;base64,' + b64
var blob = dataURLtoBlob(url)
```

## Test

[Unit tests](https://blueimp.github.io/JavaScript-Canvas-to-Blob/test/)

## License

The JavaScript Canvas to Blob script is released under the
[MIT license](https://opensource.org/licenses/MIT).

---
_Source: https://npm.io/package/blueimp-canvas-to-blob · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._