EasyEDA's preview dialog and toolbar can be resized and double click the Title toroll up, check the below Gif guide.
Oops.
The link to the original Gif has been broken but this describes resizing/hiding the top and side Toolbars:
https://easyeda.com/forum/topic/First_tool_bars-o531nJH20
To make the floating Preview and Toolbars roll up and back down, either:
To hide a floating toolbar:
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Brand new interactions and interfaces.
Smooth support for design sizes of over 3W
devices or 10W pads.
More rigorous design constraints, more
standardized processes
For enterprises, more professional users.
Easy to use and quick to get started.
The process supports design scales of 300
devices or 1000 pads.
Supports simple circuit simulation.
For students, teachers, creators.
Brand new interactions and interfaces. 
Easy to use and quick to get started. 
Oops.
The link to the original Gif has been broken but this describes resizing/hiding the top and side Toolbars:
https://easyeda.com/forum/topic/First_tool_bars-o531nJH20
To make the floating Preview and Toolbars roll up and back down, either:
To hide a floating toolbar: