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iOS image and video upload

Last updated: Apr-23-2025

Cloudinary provides support for uploading media directly from your mobile application to your Cloudinary product environment, without going through your servers first. This method allows for faster uploading and a better user experience. It also reduces load on your servers and reduces the complexity of your applications.

This page covers common usage patterns for iOS image and video upload with Cloudinary.

For details on all available upload functionality, see the Upload guide, and the upload method of the Upload API Reference.

For security reasons, mobile applications shouldn't contain your Cloudinary product environment credentials. You can use a signed upload, but that requires generating an authentication signature on your backend. In most cases, you will probably use unsigned uploads that generally provide all the functionality you need for your mobile application, while restricting upload options that require more security.

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Upload method

The upload request is managed by the upload method, which accepts the file to upload as its only parameter. The file can be specified as either a url or data object.

Note
The file is uploaded based on a background URL session. Even if your app is down, the upload will continue/resume on reconnect.

The OS attempts to initiate the upload immediately but the upload may be rescheduled depending on the system's current network, memory and cpu needs. The upload results are dispatched asynchronously and callbacks can be defined per request.

The following simple example uploads an image called imageFile.jpg using the default settings:

The result of the upload API call is a CLDUploadResult object that provides information about the uploaded image, including the assigned public ID of the image and its URL.

Note
Uploading PNG files requires preprocessing with an image encoder, see Preprocess image uploads for more details on using the CLDImagePreprocessChain() object, and setting the encoder to EncodingFormat.PNG.

Unsigned upload

Unsigned upload is an option for performing upload without the need to generate a signature on your backend. Unsigned upload options are controlled by an upload preset: to use this feature, you first need to enable unsigned uploading for your Cloudinary product environment from the Upload Presets page of the Console Settings.

An upload preset is used to define which upload options will be applied to media assets that are uploaded unsigned with that preset specified. You can edit the preset at any point in time (or create additional upload presets).

Signed upload

Important

Signed uploads require a signature which needs to be created using your api_secret. You should never expose your secret in client side code and therefore you need to generate an authentication signature on your backend. iOS signed upload with backend support should be implemented in conjunction with one of Cloudinary's backend frameworks (Java, .NET, etc). The various backend frameworks implement helpers to be used in conjunction with iOS, as well as automatically generate the authentication signature for the upload.

To implement signed uploads from an iOS device to your Cloudinary product environment you must:

  1. Provide a signature generated on your backend.
  2. Include the apiKey configuration parameter in your front end iOS configuration.
  3. Add the signature and timestamp to the upload options with the setSignature method.
  4. Call the signedUpload method to upload the file.

For example, to upload an image called imageFile.jpg, set the publicId to newId, and sign the upload request:

Upload options

You can pass an instance of CLDUploadRequestParams, with any extra parameters you'd want to pass, as part of the upload request. For example, to upload an image called imageFile.jpg using an upload preset called samplePreset:

If you want to include more than one upload parameter in the request you can chain them together. For example, to upload an image called dog.jpg, set the publicId to MyDog, and add the tag animal:

Note
For security reasons, only this restricted set of upload options can be specified directly when performing unsigned upload calls. All other upload parameters can only be specified within the upload preset.

Chunked upload

The SDK includes the uploadLarge method which offers more tolerance for network issues. This method uploads a large file to the cloud in chunks, and is required for any files that are larger than 100 MB. By default, the chunk size is set to 20 Megabytes but can be set to as low as 5 Megabytes with the chunkSize parameter. For example, uploading a large video file called myVid.mp4 and setting the chunk size to 6 Megabytes:

Cancel an upload

If you need to cancel an upload in progress, you can use the cancel method:

Callbacks

You can track the upload progress by passing a progress closure as part of the upload request, that is called periodically during the data transfer. For example:

You can also handle the response by adding a completionHandler closure to be called once the upload request has finished. For example:

Preprocess image uploads

You can pass an instance of CLDImagePreprocessChain, with any steps for preprocessing the image before uploading, as part of the upload request. The following types of processing steps are currently available:

Step Type Parameter Description
limit (width, height) Scales down the image to fit within a bounding box of the given dimensions.
rotate (degrees) Rotates the image by the requested degrees (clockwise).
dimensionsValidator (minWidth, maxWidth, minHeight, maxHeight) Verifies the minimum and maximum dimensions for the image. Throws an error if the image does not fit within these dimensions.
customImageEncoder (format, quality) Saves the image using the given format (EncodingFormat.JPEG or EncodingFormat.PNG) and quality.

For example, to limit an image to a size of 500x500 pixels, make sure that the image is at least 10x10 pixels in size, rotate the image by 90 degrees and change the format to PNG with a quality of 70:

Note
In the case that you need to create your own preprocessing step you can pass a CLDProcessStep closure with the addStep method.

Preprocess video uploads

As with images, you can also preprocess videos by transcoding them to a different size or format using an instance of the CLDVideoPreprocessChain as part of the upload process. This helps to handle larger video uploads. The following types of processing steps are available:

Step Type Parameter Description
setOutputFormat format Sets the output format for the video. Possible values: .mov, .mp4 and .m4v. Default: .mov.
setOutputDimensions (width, height) Sets the output dimensions for the video, the video will be scaled down to the specified size.
setCompressionPreset preset Applies a compression export preset to the output. See Export presets for possible values. Default: AVAssetExportPresetPassthrough.
dimensionsValidator (minWidth, maxWidth, minHeight, maxHeight) Verifies the minimum and maximum dimensions for the video. Throws an error if the video does not fit within these dimensions.

For example, to limit a video to a size of 500x500 pixels, make sure that the video is at least 250x250 pixels in size, change the format to MP4 and use the AVAssetExportPresetHighestQuality compression preset:

iOS upload widget

The iOS upload widget offers an interactive user interface that enables your users to edit and then upload files to your Cloudinary product environment. The widget, requiring just a couple lines of code to integrate, eliminates the need to develop certain in-house interactive media upload capabilities. Currently, the widget provides an interactive cropping capability and allows rotation of an image before uploading. You call the upload widget by instantiating a new CLDUploaderWidget and calling its presentWidget() method with the calling ViewController (using self in this example):

iOS upload widget options

The upload widget takes five parameters that control its basic behavior:

Name Type Nullable Description
cloudinary CLDCloudinary No The Cloudinary instance used for uploading.
configuration CLDWidgetConfiguration yes See the table below.
images UIImage Array yes Images to preload into the widget.
videos AVPlayerItem Array yes Videos to preload into the widget
delegate CLDUploaderWidgetDelegate yes Delegate for upload widgets callbacks. This is used to get notified when the widget is closed or canceled.

Note
If both images and videos are empty, the widget will automatically launch the device's file picker. The configuration parameter allows for some more advanced customization options, by creating a new instance and sending it to the widget's constructor.

The configuration object takes the following parameters:

Name Type Default Description
allowRotate Bool true Whether to allow rotation of images in the widget
initialAspectLockState AspectRatioLockState (enum) enabledAndOff Sets up the mode of the aspect ratio lock.
uploadType CLDUploadType (enum: signed or unsigned+preset) signed Signed upload or unsigned (also provide the preset).

A code example with more options:

iOS upload widget callbacks

A class implementing the CLDUploaderWidgetDelegate is used to receive callbacks from the widget. It's common practice to have the calling view controller implement that protocol and send self to the widget's constructor (such as in the example above).

The protocol has three methods:

  1. func uploadWidget(_ widget: CLDUploaderWidget, willCall uploadRequests: [CLDUploadRequest])
    This is the main callback - it informs the caller that the uploads are starting, passing on the list of references to active uploads. This allows the caller to set up callbacks per request (if required), track progress and cancel the requests. This is the same request object returned from the regular iOS upload methods.

  2. func widgetDidCancel(_ widget: CLDUploaderWidget)
    Notifies the caller that the widget was canceled.

  3. uploadWidgetDidDismiss
    Notifies the caller that the widget was dismissed and is no longer visible.

Add your own callback code by calling uploadRequests within a controller that implements the CLDUploaderWidgetDelegate protocol:

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