# Share and upload files

Attach files to messages, including images, documents, sound, and video.

First, [open the compose box](/help/open-the-compose-box). Then

* **Drag and drop** files into the compose box.
* **Copy and paste** files into the compose box.
* **Click the paperclip** (<i class="fa fa-paperclip"></i>) icon at
  the bottom of the compose box to find files on your computer.

Zulip will insert a link to the file, in Markdown format:
`[link text](URL)`. You can modify the `link text` to whatever you want.

Zulip will automatically generate a **thumbnail** of the file when you send
it, if it can. You can
[preview the message](/help/preview-your-message-before-sending) before
sending to see what the thumbnail will look like.

## Troubleshooting info

Zulip does not generate thumbnails for messages with more than ten
attachments.

The maximum file size for attachments is 25MB in most Zulip installations.
This limit can be changed by the server administrator.

## Related articles

* [Manage your uploaded files](/help/manage-your-uploaded-files)
* [View and browse images](/help/view-and-browse-images)
