# 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 modily 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 5
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 an image at full size](/help/viewing-images)