You can also share files to Messenger directly from the Dropbox mobile app. Tapping Open will take the recipient to their Dropbox mobile app to preview and save the shared file. will be shared as a link to the Dropbox file. All other files, like PDFs, spreadsheets, etc.
Videos, images, and GIFs are displayed - and can be opened - directly in Messenger chats. Once the install is finished, sign in to Dropbox and go back to Messenger to start sharing.
This will take you to your app store to install the app. If you did not install the Dropbox mobile app as per above, you can do so now by tapping on Install next to Dropbox under the Get Apps for Messenger section. If not, you will be prompted to sign in to your Dropbox account first. Provided you are logged into Dropbox on your smartphone, you will be able to browse for a photo, video, GIF or any other file to share. Inside a conversation, tap the More button (three dots) and select Dropbox from the list of available source apps. Share Dropbox videos, photos, GIFs, more directly in Messenger, via Facebook