Hello Tomasz

Thanks for posting in the Lucidchart Community! Unfortunately the size of the default circle arrowhead cannot be changed. The location of the arrowhead in relation to the border of a shape is also unfortunately not able to be changed. I understand that this may hinder your workflow - my apologies for that inconvenience! As a workaround you can add a smaller circle shape from the 'Standard' or 'Flowchart' library at the end of your line and group that shape and the line together. This should allow you to overlap shape borders and edit the size of the circle to be smaller than the default arrowhead. I’ve also converted this post to an idea so that it’s visible to others within the Product Feedback section of the community - from here, they can upvote it and add details of their own.

Finally, for more information on how Lucid manages feedback via this community, take a look at this post:

Please let me know if you have any further questions or if you experience any other difficulty while using Lucidchart!

Done. Hope to see the feature soon.

I’m excited to share that this is now available in both Lucidchart and Lucidspark. Learn more here: https://help.lucid.co/hc/en-us/articles/14560101705364-Add-and-style-lines-in-Lucidspark#line-format-options!

Lucidspark: 

Lucidchart: