Link/reference to symbol

[tolleif]

Problem: I have created a symbol which I'm using many times in my Drawio file, in multiple pages. If I want to change my symbol a little bit, I have to change it many places. I will always forget a few instances.
If the symbol have an embedded image, then the Drawio file will become very big with redundant data.

Solution: A new insertable object that is just a pointer/reference/link to another existing symbol in the same Drawio file. Possibly in another page. I.e. "symbol library page"

Examples:

• Quick Mass Edit: I have a symbol for a valve which I use in a bunch of PI&D drawings. I want to change the valve a bit, but I only want to change the reference symbol, all linked objects immediately display the change.

• I have a little company logo symbol which I use in many pages but then the company changes name again. (this can often be solved with background diagram, but not always practical or background picture feature already used for other purpose)

• Storage reduction: I have a JPG/PNG image that's 100kbyte. Suddenly my Drawio file is tens of megabytes big when I re-use it often.

For advanced topics, property override on linked objects would be cool. I link to a reference symbol and then a few of them I change the fill color. Ok, getting a bit ahead of myself here, let's start with pebbles. :)

Thank you for your time.

[MarkOates]

I would like this as well. In my case I have a few composite visuals that are repeated in several different diagrams and may require revisions.

Also, it would be great if I could create these symbols in isolation in, say, another page, and then hot-link them into a larger more complex diagram and have them update dynamically.

Another reason this would be convenient is it would make it easier to export the smaller diagrams in isolation for use elsewhere (like documentation).

[davidjgraph]

Current State in Draw.io

1. There is No “Reference Symbol” Feature Yet

   draw.io currently does not support “linked symbols” or master-symbol references like you might find in some CAD or advanced diagramming software.

   Each copy of a shape is a full duplicate. If you change one, the others do not update.

   Embedded images are also duplicated, so files grow quickly if you use the same image in many places.

2. Existing Workarounds

   Custom Libraries:
   You can add your symbol to a custom library and insert it many times, but these are still copies, not references. Changes to the library symbol do not update placed symbols.

   Background Images/Page:
   You already mention this; setting a page as a background helps for “whole-page” objects, but not for in-diagram references or overlays.

   SVG Symbol with URL Reference:
   Not currently possible in draw.io; SVG is not supported across the app for this purpose.

   Copy-paste by selection:
   This is manual and error-prone.

Feature Request / Solution Proposal

What you describe is essentially a request for “symbol instances” or “master shapes”:

Define a “master” shape somewhere (possibly in a dedicated library page).

Insert as a reference/link on other pages or locations.

When the master is edited, all references automatically update.

(Advanced: Allow certain property overrides per instance, like fill color.)

This feature is not currently available, but has been requested before by others for similar reasons (maintainability, file size, consistency).