Sharing Files

With attachments, you can share additional information that will help your team to visually understand your ideas. Sharing videos, voice recordings, screenshots, and photos will make your messages more effective and clear.

How to Attach Files

You can attach files in the following ways:

  • Use the attachment icon - click the paperclip icon inside the message input box
  • Drag and Drop
  • Paste from the clipboard - this feature is supported in Chrome and Edge browsers

File Previewer

Mattermost has a built-in file previewer that you can use to:

  • Download files
  • Share public links
  • View media

Click the thumbnail of an attached file to open it in the file previewer.

Downloading Files

You can download an attached file by clicking the download icon next to the file thumbnail.

Viewing Media:

The following media formats are supported on most browsers:

  • Images: BMP, GIF, JPG, JPEG, PNG, SVG
  • Video: MP4
  • Audio: MP3, M4A
  • Files: PDF, TXT

Other document previews (Word, Excel, PPT) are not yet supported.

Attachment Limits and Sizes

Please note that Mattermost supports a maximum of five (5) attached files per post.

The default maximum file size is 50 MB, but this can be changed by the System Admin.