A note in Trilium can own one or more attachments, which can be either images or files. These attachments can be displayed or linked within the note that owns them.

This can be especially useful to include dependencies for your scripts. The Weight Tracker shows how to use chartjs which is attached to the script note.

Each note exclusively owns its attachments, meaning attachments cannot be shared or linked from one note to another. If an attachment link is copied to a different note, the attachment itself is duplicated, and the copies are managed independently thereafter.

Attachments, especially image files, are the recommended method for embedding visuals in notes. It is important to link image attachments within the text of the owning note; otherwise, they will be automatically deleted after a configurable timeout period if not referenced.

Types of attachments

There are two different types of attachment:

User content, representing files or images that are uploaded and part of the content of the note.
System attachments which are used internally by Trilium and can be of multiple types, including:
- Collections to store information about views such as the column information for the Kanban Board.
- Icons and cover images for Link Previews.
- Debug information for some importers such as Microsoft OneNote (only if the debug flag was enabled at import time).

The system attachments are displayed at the end of the attachments list, in a dedicated section (Generated by Trilium).

Attaching files from a text note

To attach files to a Text note and link them in its content, press the Attach file button in the Formatting toolbar, next to the image upload button, and select one or more files. The arrow beside the button lists the same action as Attach file as a link, followed by Attach and embed file, which embeds the files instead (see below). Both actions are also available as Attach file as a link and Attach and embed file in the Slash Commands.

Each file becomes an attachment of the note, and a link to it is inserted at the cursor. Several files produce several links, separated by a space.
While a file uploads, its link shows the file name and a toast shows the progress.
Pictures appear as links rather than images, and are attached exactly as they are, without being compressed. To display a picture in the text, use the image upload button instead (see Images).

Dragging a file that is not a picture from the file explorer onto the text also attaches it and inserts a link to it.

Acting on an attachment link

Right-clicking a link to an attachment shows the ways to open it, followed by actions on the attachment: opening it externally, downloading it, uploading a new revision, renaming or deleting it, and converting it into a note.

Links follow changes to their attachment: renaming it updates the title they show, and deleting it removes them from the text notes open for editing at that moment. Converting it into a note turns its links into links to the new note.

Embedding an attachment

An attachment can be shown in the text instead of linked, the way Include Note shows a note: a picture is displayed, a PDF, a video or a document is previewed, and a code or text file is shown with syntax highlighting. An embedded code file can also be edited in place (see Editing an include in place in Include Note).

To attach files and embed them straight away, select Attach and embed file from the arrow beside the Attach file button. Each file gets an embed of its own, which shows the file name while the file uploads.
To embed an attachment that is already linked, right-click a link to it in a text note being edited and select Convert link to an embed, at the end of the menu.
A drawing canvas, inserted with Drawing canvas in the Insert menu, is an embed of a Canvas.excalidraw attachment that can be drawn on in place (see Drawing canvases in Include Note).
An embed gets the box size that suits the attachment, as a new included note does (see Box sizes there). To change its size, select the embed and use the box size menu in its toolbar, or the Size submenu of its More actions menu. A Small, Medium or Expandable embed can also be resized by dragging its handles (see Resizing there).
An embed can have a caption, as an included note can (see Caption there).
To show only the attachment, select the embed and press the (Show title) button in its toolbar, as for an included note (see Title there).
To open the attachment in a new tab, press the (Open in new tab) button at the end of the embed's title.
An embed of size Tiny shows only the title of the attachment and its size, in a single row. Its buttons are Open externally and Download.
To show an embed of size Medium or Full on the whole screen, press the (Fullscreen) button at the end of its title. To return, press (Exit fullscreen) in the top-right corner, or Esc.
To turn the embed back into a link, select it and press the Convert to link button in its toolbar. Convert to link also ends the menu that right-clicking the title row of the embed or pressing its More actions button opens.

An embed follows its attachment like a link does. Converting the attachment into a note turns the embed into an included note. In a shared note, an embedded picture is displayed with its caption, and any other attachment, or a picture in a Tiny embed, appears as a link to download it.

Converting notes to attachments

File notes can be easily converted to attachments of the parent note.

To do so:

For a single note, press the context menu from the Note menu and select Convert into attachment.
For multiple notes, select the given notes in the Note Tree, right click → Advanced → Convert to attachment.

Attachment previews

Attachments share the same content preview for images, videos, PDFs, etc. as the File note type.