Here, you'll find descriptions of specific and proprietary terms that we use on our website, and in our interfaces and APIs.


The main entity within your Uploadcare account. Each project has a unique name, dedicated storage, settings, API keys, etc. Create as many projects as you need. You can set up shared access to a corporate project for multiple Uploadcare accounts by contacting support.


Uploadcare Public and Secret API keys are used to identify ownership and establish a connection between your application and your Uploadcare project. The Public Key is used for uploading files to a certain project, and the Secret Key is used for file management, to perform async operations, etc. Also, your Secret Key provides Security for uploads and delivery.


The means of uploading your files into your Uploadcare storage. Developers can utilize File Uploader (with integrations for all popular frameworks) or API clients for all popular programming languages, including mobile platforms.


A Universally Unique Identifier given to each file when it's uploaded to your Uploadcare project. UUID is a part of CDN URL, and can be used to manipulate file via REST API.

File Uploader

A website file uploading module that you can embed into your website as a dialog window, panel, or button. File Uploader is linked with your Uploadcare project via the Public Key. This module works in all modern browsers.

File Uploader API

The Application Programming Interface in the form of a JS SDK for File Uploader customization. The interface, behavior, and File Uploader features can be customized to match your website design and function. For example, you can add custom file validation functions to File Uploader.

Upload Sources

The sources from which you and your end users can upload images and other content. An uploading source can be a local drive, camera, social networks, or cloud services, such as Google Photos, Facebook, Instagram, Facebook, Dropbox, Flickr, etc.

Custom OAuth Applications

An option to use the OAuth protocol to connect to Upload Sources. With this feature, your app will request permissions to your app when accessing Upload Sources.


Your primary project's storage that keeps the original file versions. When applying CDN operations, the original files stays intact. Overall storage size (for all projects) is set by your plan.


A process of saving your files to Uploadcare storage after they're uploaded. The Automatic file storing option stores all incoming files as long as they’re not explicitly deleted.

Custom Storage

Amazon S3 Bucket storage, which you can use additionally to your Uploadcare storage if your solution or company policy requires storing all files with Amazon. Some features like CDN operations (e.g., image processing) won’t be available.


Uploadcare CDN is a global system that delivers files to end users around the world. It uses other CDN providers for better coverage, speed, and reliability. Whenever a website visitor accesses a file or its variant, it gets copied to the closest CDN node and then it gets cached there.

CDN Operations

Commands that are added to the CDN link that can transform images, convert documents, encode videos, get file info, and do other operations without any coding.


Use your own domain for CDN links to your files stored with Uploadcare. By default, all file URLs use domain. By setting a Custom CNAME, the file URLs can use instead.

Image Processing

On-the-fly image transformations such as compress, resize, crop, rotate, flip, change colors, blur, sharpen, set overlay, and many other (about a hundred). The transformations are applied in real time at the moment when the image is requested by the client. The transformed images are cached on the CDN and load even faster the next time.


Proxy allows you manage files that are already hosted on your website and optimize their delivery with Uploadcare while skipping the manual upload (each file is uploaded to CDN after the first request).

Proxy Endpoint

A Proxy Endpoint is a URL prefix that goes before the original link to the file on your domain. For example This will deliver image.jpg file using Uploadcare CDN.


An option that allows uploading images from the domains you trust when using Proxy and Adaptive Delivery. This can help you build a more secure and closed system for end users. Each Uploadcare project has its own Whitelist.

Adaptive delivery

Next-generation responsive design. Adaptive Delivery JS library helps you optimize image content automatically depending on a client's device, web browser and other parameters.

Video processing

The process of video conversion, that enables your video file to be played on the web by the modern browsers, and gives it an optimal file size. Also, you can apply some transformations on the video processing step. This feature is available via the REST API.

Document conversion

The process of document conversion from one format into another. For example, you can convert DOC to PDF, or a PDF into a set of images. Document conversion can be done through the REST API.


A set of options to provide security for uploading, access and delivery of your files to end users. Includes Secure Uploading and Secure Delivery.

Secure Uploading

A feature to control who can upload files to an Uploadcare project within your account. Your backend generates a signature using a Secret Key and includes an expiration time parameter. A client is required to include a valid signature in an upload request. It works with Uploadcare File Uploader and Upload API.

Secure Delivery

This security feature lets you control who and for how long can access files in your project via signed URLs. In other words, it's a CDN URL with a signature generated on your backend (similar to Secure Uploading). This feature works in conjunction with a Custom CNAME.

Uploadcare APIs

A set of APIs for all system components. The Upload API is used to upload files while the REST API is used to manipulate stored files (e.g., store, copy, delete, apply conversions).