Drupal doesn’t support the ability to replace existing files. You can create and delete files, but you can’t replace a file without using a module. If you try to upload a file with the same name Drupal will append “_0”, “_1”, etc… to the filename and increment it.
Luckily two modules can help with replacing files, and they’re called Media Entity File Replace and File Replace.
What is the main difference between Media Entity File Replace and File Replace?
Both modules will replace “files” whilst retaining the original file’s filename by performing an “overwrite” function in the backend. In Drupal, an uploaded “file” can be a “media entity” or a “file entity”.
As the module names suggest, the main difference is that Media Entity File Replace works at the media entity level, whereas File Replace works at the file entity level.