In iOS 13, Apple has made the built-in Files app from an extremely rudimentary file browser into a fully functional app that meets the needs of most users. New features include the ability to compress a file or a set of files directly from your iPhone into a standard ZIP archive.
There are several reasons why you want to create a ZIP archive. For example, if you share a group of photos or files with someone via e-mail, compressing may help reduce the size of the files to match the generally narrow size limits of e-mail. Compressing infrequently used files can also help save valuable cloud space and the amount of cellular data you need to use when uploading the files. With files, you can quickly and easily create ZIP archives.
Compressing a single element
To compress a single file or folder, hold down the button or 3D Touch on the item in the File app. At the bottom of the displayed context menu is the "Compress" button. Tap and Files compresses the file or folder into a file named Filename.zip, where Filename is the name of the selected file or folder. The archive is stored in the same directory as the selected object.
When compressing multiple items If you want to include a mix of files and folders, tap Select at the top right and select all the files you want to include in the archive. Alternatively, you can tap and drag with two fingers to enter select mode and select multiple items with a single swipe, similar to Selecting multiple messages in Mail.
After you have selected the files you want to archive in the ZIP file, tap the ellipsis (•••) at the bottom right and then the "Compress" button. Similar to compressing a single file, the files are compressed and placed in the same directory, even though the resulting ZIP archive is named "Archive.zip".
After you've created the archive, you can rename it , move or release. Creating ZIP archives works anywhere in the file app, even with third-party plug-ins such as Adobe Creative Cloud, Box, Boxcryptor, Dropbox, Google Drive, Microsoft OneDrive, and SugarSync. Although this feature is not widely used by most users, it makes the iPhone a more powerful computer right in your pocket.