Uploadcare Basics

Uploadcare is a hassle-free file infrastructure. We cover every aspect of your file handling. This section walks you through our workflow and features.

There are four fundamental concepts we deal with: uploads, storage, delivery, and processing.


First, you can upload files right in a browser on any device. Your local storage, social media or a cloud can be a source for those uploads. That is done with Uploadcare Widget. What you get by default is a button,


You can add the widget to a page with just three lines of code,

<!-- The best place for this is your <HEAD> tag -->
<script>UPLOADCARE_PUBLIC_KEY = "demopublickey";</script>
<script src="https://ucarecdn.com/libs/widget/3.x/uploadcare.full.min.js" charset="utf-8"></script>

<!-- And this is how you set the place on a page where the widget will appear. Do not miss the name attribute -->
<input type="hidden" role="uploadcare-uploader" name="my_file" />

Uploadcare Widget works as a simple form element and lets you upload any file types including images, videos, PDFs, and other documents. We support files of up to 5TB in size and ensure their reliable and fast uploading with our distributed uploads network.

There are other install methods like NPM or Bower. You have probably noticed UPLOADCARE_PUBLIC_KEY was set to demopublickey. The public key points to an Uploadcare project your uploads go to. Just change demopublickey to a public_key of any project in your Uploadcare account account to route the widget uploads there. Our demo account would still accept your uploads, but keep in mind we clear its storage every 24 hours. And that is where we get to the next concept, Storage.


You do not have to store any of the uploaded files on your servers. All uploads go to our storage, and you receive unique file identifiers or UUIDs. You can store those in your database, textfile or even Moleskine.

This is how UUIDs look like,


In fact, you may prefer custom storage over ours. When you stick with our storage, your files also get to our CDN: that is for their lightning fast delivery in 130 countries across the globe.


Uploadcare features a smart CDN that powers the delivery of every file uploaded to your account. Any file on Uploadcare can be accessed by using UUID-based URLs,


You can notice the original filename is still there: at the very end of the URL. In fact, you can put any file name after the trailing /. This can be helpful when doing SEO or using custom names for processed file versions.

For instance, the image file in the above example is processed. We optimized it for faster delivery by adjusting its size and quality. Take a look at those resize and quality URL directives. Same stuff can be applied to videos. All that relates to our next concept, Processing.


The Uploadcare Image Transformations are coupled with our CDN delivery. File transformations are performed on-the-fly, and multiple caching layers are used to ensure popular files are delivered even faster. Media processing works simply by adding URL directives; we call those operations. By using operations, you can acquire file info, filter images and video, transform GIFs into videos, implement object recognition, and more.

For instance, let us enhance the above image to further increase its engagement rates on your Instagram or Pinterest,


That is it, folks

Well, not really. There is much more. You can implement Uploadcare via our Libraries and Integrations or even operate on the lowest level via our REST API and Upload API that also allows you to implement extra security features to instantly get your system PrivacyShield, GDPR, HIPAA or SOC2 compliant.

And, of course, the true Uploadcare journey starts with creating an account, there is a forever Free plan. You can always post a question in our Community Area or contact our support.

Don’t spend weeks on what you can do in minutes.