Media File Renamer is the best plugin for renaming your image and other media files from media library. The good thing about this plugin is that when you rename files physically by updating their titles, the plugin automatically updates theirs links inside your posts. It simply update all references (like img, src, url) to the media file in its associated post. But also there are other plugins designed for media renaming with more or less features.
Following are some good plugins for renaming media library files with their name in URLs:
Media File Renamer
It allows you to rename physically the media files by updating their titles. It also updates theirs links in the posts automatically. Using File Renamer (in Tools), you can bulk-rename all your files all at once, or only the flagged files, but it’s recommended to do the renaming through the Media Library directly.
Media Rename
The plugin allows you to easily rename (and retitle) your media files, once uploaded. The plugin not only renames your media, but also will checks all posts, metas and options on your site and change the links to the current media file, so they don’t get broken.
Rename Media Files
Simply enables renaming of media files in WordPress. The plugin adds a field in media edit form where you can enter new file name. After renaming, it’ll regenerate all intermediate image sizes (if media file is an image) and update all links inside posts.
