diff --git a/public/src/modules/pictureCropper.js b/public/src/modules/pictureCropper.js
index 40ed5ede89..245312f16d 100644
--- a/public/src/modules/pictureCropper.js
+++ b/public/src/modules/pictureCropper.js
@@ -106,14 +106,14 @@ define('pictureCropper', ['cropper'], function (Cropper) {
 							return;
 						}
 
-						cropperModal.find('#upload-progress-bar').css('width', '100%');
+						cropperModal.find('#upload-progress-bar').css('width', '0%');
 						cropperModal.find('#upload-progress-box').show().removeClass('hide');
 
-						var socketData = {};
-						socketData[data.paramName] = data.paramValue;
-						socketData.imageData = imageData;
-
-						socket.emit(data.socketMethod, socketData, function (err, imageData) {
+						socketUpload({
+							data: data,
+							imageData: imageData,
+							progressBarEl: cropperModal.find('#upload-progress-bar'),
+						}, function (err, result) {
 							if (err) {
 								cropperModal.find('#upload-progress-box').hide();
 								cropperModal.find('.upload-btn').removeClass('disabled');
@@ -121,7 +121,7 @@ define('pictureCropper', ['cropper'], function (Cropper) {
 								return app.alertError(err.message);
 							}
 
-							callback(imageData.url);
+							callback(result.url);
 							cropperModal.modal('hide');
 						});
 					});
@@ -143,6 +143,36 @@ define('pictureCropper', ['cropper'], function (Cropper) {
 		});
 	};
 
+	function socketUpload(params, callback) {
+		var socketData = {};
+		socketData[params.data.paramName] = params.data.paramValue;
+		socketData.method = params.data.socketMethod;
+		socketData.size = params.imageData.length;
+		socketData.progress = 0;
+
+		var chunkSize = 100000;
+		function doUpload() {
+			var chunk = params.imageData.slice(socketData.progress, socketData.progress + chunkSize);
+			socket.emit('uploads.upload', {
+				chunk: chunk,
+				params: socketData,
+			}, function (err, result) {
+				if (err) {
+					return app.alertError(err);
+				}
+
+				if (socketData.progress + chunkSize < socketData.size) {
+					socketData.progress += chunk.length;
+					params.progressBarEl.css('width', (socketData.progress / socketData.size * 100).toFixed(2) + '%');
+					return setTimeout(doUpload, 100);
+				}
+				params.progressBarEl.css('width', '100%');
+				callback(null, result);
+			});
+		}
+		doUpload();
+	}
+
 	function checkCORS(cropperTool, data) {
 		var imageData;
 		try {
@@ -177,7 +207,7 @@ define('pictureCropper', ['cropper'], function (Cropper) {
 		var file = fileInput[0].files[0];
 		var fileSize = data.hasOwnProperty('fileSize') && data.fileSize !== undefined ? parseInt(data.fileSize, 10) : false;
 		if (fileSize && file.size > fileSize * 1024) {
-			return app.alertError('[[error:file-too-big, ' + fileSize + ']]');
+			return showAlert('error', '[[error:file-too-big, ' + fileSize + ']]');
 		}
 
 		if (file.name.endsWith('.gif')) {
diff --git a/src/socket.io/index.js b/src/socket.io/index.js
index 6e6be257ae..4168aa3a1e 100644
--- a/src/socket.io/index.js
+++ b/src/socket.io/index.js
@@ -69,6 +69,14 @@ function onConnection(socket) {
 	socket.on('*', function (payload) {
 		onMessage(socket, payload);
 	});
+
+	socket.on('disconnect', function () {
+		onDisconnect(socket);
+	});
+}
+
+function onDisconnect(socket) {
+	require('./uploads').clear(socket.id);
 }
 
 function onConnect(socket) {
@@ -148,7 +156,8 @@ async function onMessage(socket, payload) {
 
 function requireModules() {
 	var modules = ['admin', 'categories', 'groups', 'meta', 'modules',
-		'notifications', 'plugins', 'posts', 'topics', 'user', 'blacklist', 'flags',
+		'notifications', 'plugins', 'posts', 'topics', 'user', 'blacklist',
+		'flags', 'uploads',
 	];
 
 	modules.forEach(function (module) {
diff --git a/src/socket.io/uploads.js b/src/socket.io/uploads.js
new file mode 100644
index 0000000000..9355a8ac71
--- /dev/null
+++ b/src/socket.io/uploads.js
@@ -0,0 +1,52 @@
+'use strict';
+
+const socketUser = require('./user');
+const socketGroup = require('./groups');
+const image = require('../image');
+const meta = require('../meta');
+
+const inProgress = {};
+
+const uploads = module.exports;
+
+uploads.upload = async function (socket, data) {
+	const methodToFunc = {
+		'user.uploadCroppedPicture': socketUser.uploadCroppedPicture,
+		'user.updateCover': socketUser.updateCover,
+		'groups.cover.update': socketGroup.cover.update,
+	};
+	if (!data || !data.chunk || !data.params || !data.params.method || !methodToFunc[data.params.method]) {
+		throw new Error('[[error:invalid-data]]');
+	}
+
+	inProgress[socket.id] = inProgress[socket.id] || {};
+	const socketUploads = inProgress[socket.id];
+	const method = data.params.method;
+
+	socketUploads[method] = socketUploads[method] || { imageData: '' };
+	socketUploads[method].imageData += data.chunk;
+
+	try {
+		const maxSize = data.params.method === 'user.uploadCroppedPicture' ?
+			meta.config.maximumProfileImageSize : meta.config.maximumCoverImageSize;
+		const size = image.sizeFromBase64(socketUploads[method].imageData);
+
+		if (size > maxSize * 1024) {
+			throw new Error('[[error:file-too-big, ' + maxSize + ']]');
+		}
+		if (socketUploads[method].imageData.length < data.params.size) {
+			return;
+		}
+		data.params.imageData = socketUploads[method].imageData;
+		const result = await methodToFunc[data.params.method](socket, data.params);
+		delete socketUploads[method];
+		return result;
+	} catch (err) {
+		delete inProgress[socket.id];
+		throw err;
+	}
+};
+
+uploads.clear = function (sid) {
+	delete inProgress[sid];
+};