If you’ve ever spent any amount of time messing with PHP configuration files to get a file to upload, you know that uploading large files can be a real pain. You have to find the loaded php.ini file, edit the upload_max_filesize and post_max_size settings, and hope that you never have to change servers and do all of this over again. I ran into this problem myself while working on WP Migrate DB Pro – one of the features that will be going into the next release is the ability to upload and import an SQL file. Since WP Migrate DB Pro is used on a wide variety of servers, I needed to create a reliable upload tool that can upload large files without hitting upload limits.
With that in mind, let’s create a sample WordPress file upload plugin to take a look at the FileReader API and learn how to use it to process large file uploads.
Since the FileReader API is baked right