Upgrade Guide

From 2.x to 3.0.0

  • Deprecated objects/methods has been removed:
    • options.base64 in generate() (the base64 type is still valid)
    • options.base64, options.binary, options.dir, options.date on ZipObject (see the 2.3 upgrade section)
    • JSZip.utils
    • JSZip.prototype.crc32, JSZip.prototype.utf8encode, JSZip.prototype.utf8decode
    • JSZip.base64 (you can get the content of a file directly as a base64 string)
  • JSZip.compressions has been removed.
  • On ZipObject, the synchronous getters has been replaced by async() and nodeStream().
  • The generate() method has been replaced by generateAsync() and generateNodeStream().
  • The type option in generate() is now mandatory.
  • The “text” type has been replaced by the “string” type, a binary string is named “binarystring”.
  • The load() method and the constructor with data (new JSZip(data)) have been replaced by loadAsync().
  • When adding a file, the option createFolders now defaults to true. If you don’t want to create sub folders, set it to false.
  • zip.generateAsync() and zip.generateNodeStream() now depend on the current folder level.
// 2.x
// 3.x
.then(function (content) {
    // use content

// 2.x
// 3.x
.then(function (content) {
    // use content

// 2.x
new JSZip(data);
// zip.file(...)
// 3.x
JSZip.loadAsync(data).then(zip) {...};
zip.loadAsync(data).then(zip) {...};
// here, zip won't have (yet) the updated content

// 2.x
var data = zip.file("img.jpg").asBinary();
var dataURI = "data:image/jpeg;base64," + JSZip.base64.encode(data);
// 3.x
.then(function (data64) {
    var dataURI = "data:image/jpeg;base64," + data64;

async and loadAsync use (a polyfill of) promises, you can find the documentation here and a tutorial here.

It is worth noting that:

 * JSZip accepts these promise as input

// replace a content with JSZip v2
var content = zip.file("my_file").asText();
content = content.replace(/apples/, 'oranges');
zip.file("my_file", content);

// replace a content with JSZip v3
var contentPromise = zip.file("my_file").async("text").then(function (content) {
    return content.replace(/apples/, 'oranges');
zip.file("my_file", contentPromise);

 * Promises are chainable

// read, update, generate a zip file with JSZip v2
var zip = new JSZip(content);
zip.file("new_file", "new_content");
var blob = zip.generate({type: "blob"});
saveAs(blob, "result.zip");

// read, update, generate a zip file with JSZip v3
.then(function (zip) {
    zip.file("new_file", "new_content");
    // if you return the zip object, it will be available in the next "then"
    return zip;
.then(function (zip) {
    // if you return a promise of a blob, promises will "merge": the current
    // promise will wait for the other and the next "then" will get the
    // blob
    return zip.generateAsync({type: "blob"});
.then(function (blob) {
    saveAs(blob, "result.zip");

From 2.2.2 to 2.3.0

  • On ZipObject#options, the attributes date and dir have been deprecated and are now on ZipObject.
  • On ZipObject#options, the attributes base64 and binary have been deprecated.
  • JSZip.base64, JSZip.prototype.crc32, JSZip.prototype.utf8decode, JSZip.prototype.utf8encode and JSZip.utils have been deprecated.
// deprecated
// new API

From 2.0.0 to 2.1.0

  • The packaging changed : instead of loading jszip.js, jszip-load.js, jszip-inflate.js, jszip-deflate.js, just include dist/jszip.js or dist/jszip.min.js. For AMD loader users : JSZip now registers itself. You just have to put the file at the right place or configure your loader.

From 1.x to 2.x

  • JSZipBase64 has been renamed to JSZip.base64.
  • The data attribute doesn’t exist anymore : use the getters asText(), asBinary(), etc
  • The compression/decompression methods now give their input type with the compressInputType and uncompressInputType attributes.

Example for the data attribute :

// before

// after