If you need to save really large files bigger then the blob's size limitation or don't have
enough RAM, then have a look at the more advanced StreamSaver.js
that can save data directly to the hard drive asynchronously with the power of the new streams API. That will have
support for progress, cancelation and knowing when it's done writing
FileSaver.js is the solution to saving files on the client-side, and is perfect for webapps that need to generate files, or for saving sensitive information that shouldn't be sent to an external server.
Looking for
Feature detection is possible:
Pass
The standard W3C File API
Note: The standard HTML5

1: http://eligrey.com/demos/FileSaver.js/ 2: https://github.com/eligrey/canvas-toBlob.js 3: https://code.google.com/p/chromium/issues/detail?id=375297 4: https://developer.mozilla.org/en-US/docs/DOM/Blob 5: https://github.com/eligrey/Blob.js 6: https://github.com/eligrey/canvas-toBlob.js
Additionally, TypeScript definitions can be installed via:
FileSaver.js
FileSaver.js implements the saveAs()
FileSaver interface in browsers that do
not natively support it. There is a FileSaver.js demo1 that demonstrates saving
various media types.FileSaver.js is the solution to saving files on the client-side, and is perfect for webapps that need to generate files, or for saving sensitive information that shouldn't be sent to an external server.
Looking for
canvas.toBlob()
for saving canvases? Check out
canvas-toBlob.js2 for a cross-browser implementation.Supported browsers
| Browser | Constructs as | Filenames | Max Blob Size | Dependencies | | -------------- | ------------- | ------------ | ------------- | ------------ | | Firefox 20+ | Blob | Yes | 800 MiB | None | | Firefox < 20 | data: URI | No | n/a | Blob.js | | Chrome | Blob | Yes | 500 MiB3 | None | | Chrome for Android | Blob | Yes | 500 MiB3 | None | | Edge | Blob | Yes | ? | None | | IE 10+ | Blob | Yes | 600 MiB | None | | Opera 15+ | Blob | Yes | 500 MiB | None | | Opera < 15 | data: URI | No | n/a | Blob.js | | Safari 6.1+ | Blob | No | ? | None | | Safari < 6 | data: URI | No | n/a | Blob.js | | Safari 10.1+ | Blob | Yes | n/a | None |Feature detection is possible:
try {
var isFileSaverSupported = !!new Blob;
} catch (e) {}
IE < 10
It is possible to save text files in IE < 10 without Flash-based polyfills. See ChenWenBrian and koffsyrup'ssaveTextAs()
for more details.Safari 6.1+
Blobs may be opened instead of saved sometimes—you may have to direct your Safari users to manually press ⌘+S to save the file after it is opened. Using theapplication/octet-stream
MIME type to force downloads can cause issues in Safari.iOS
saveAs must be run within a user interaction event such as onTouchDown or onClick; setTimeout will prevent saveAs from triggering. Due to restrictions in iOS saveAs opens in a new window instead of downloading, if you want this fixed please tell Apple how this bug is affecting you.Syntax
FileSaver saveAs(Blob/File data, optional DOMString filename, optional Boolean disableAutoBOM)
Pass
true
for disableAutoBOM
if you don't want FileSaver.js to automatically provide Unicode text encoding hints (see: byte order mark).Examples
Saving text using require
var FileSaver = require('file-saver');
var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
FileSaver.saveAs(blob, "hello world.txt");
Saving text
var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
FileSaver.saveAs(blob, "hello world.txt");
The standard W3C File API
Blob
4 interface is not available in all browsers.
Blob.js5 is a cross-browser Blob
implementation that solves this.Saving a canvas
var canvas = document.getElementById("my-canvas"), ctx = canvas.getContext("2d");
// draw to canvas...
canvas.toBlob(function(blob) {
saveAs(blob, "pretty image.png");
});
Note: The standard HTML5
canvas.toBlob()
method is not available in all browsers.
canvas-toBlob.js6 is a cross-browser canvas.toBlob()
that polyfills this.Saving File
You can save a File constructor without specifying a filename. The File itself already contains a name, There is a hand full of ways to get a file instance (from storage, file input, new constructor) But if you still want to change the name, then you can change it in the 2nd argumentvar file = new File(["Hello, world!"], "hello world.txt", {type: "text/plain;charset=utf-8"});
FileSaver.saveAs(file);

1: http://eligrey.com/demos/FileSaver.js/ 2: https://github.com/eligrey/canvas-toBlob.js 3: https://code.google.com/p/chromium/issues/detail?id=375297 4: https://developer.mozilla.org/en-US/docs/DOM/Blob 5: https://github.com/eligrey/Blob.js 6: https://github.com/eligrey/canvas-toBlob.js
Installation
npm install file-saver --save
bower install file-saver
Additionally, TypeScript definitions can be installed via:
npm install @types/file-saver --save-dev