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VirtualTreeview is a TTreeView control built from ground up.

Its main characteristics are :

  • it is extremely fast. Adding one million nodes takes only ~700 milliseconds
  • very small memory foot print. by only allocating about 60 bytes per node
  • optimized for high speed access. It takes as few as 0.5 seconds to traverse one million nodes
  • Multiselection is supported
  • Drawing the entire tree to a bitmap or the printer is supported
  • fixed background image can be used
  • Hot style for nodes is supported
  • Nodes can have individual heights
  • Sorting via compare callback
  • Support for unicode
  • Multiple columns are supported
  • ... and many more

This component was designed for cross-platform applications.



Author: Mike Lischke
Old LCL Port: Joerg Thaler,Christian Ulrich
New LCL Port: Luiz Américo


LGPL or Mozilla Public Licence 1.1


See the project releases page

Note that v5.5.3.1 is included in Lazarus v2.0+, there is not need for a separate download.


You can checkout the source code from GitHub

It's possible to use both Subversion and Git clients


svn co

Replace lazarus_v5 by lazarus_v4 or lazarus_master to get a different version. For more info how to use Subversion, see GitHub help


git clone

Bug report / Feature request


For patches / pull requests, here. Newcomers to GitHub may want to read the help

Change Log

  • 02/06/2016 - 4.8.7 R4 and 5.5.3 R1 - First release of 5x branch + moved to GitHub
  • 20/10/2012 - 4.8.7 LCL R2 - Compatibility with Lazarus 1.0 + 64 bit support
  • 18/02/2011 - 4.8.7 LCL R1 - Sync with 4.8 branch + misc fixes
  • 11/02/2010 - 4.8.6 - First stable release of the new port

Dependencies / System Requirements

Versions 4.x or 5.x

  • Lazarus 1.6 or newer
  • fpc 2.6.4 or newer
  • LCL Extensions 0.6 or newer

Version 6.x (lazarus_master branch)

  • Lazarus 1.6 or newer
  • fpc 3.1 (trunk) or newer
  • LCL Extensions 0.6 or newer


  • If new to Lazarus, read Install Packages
  • Lazarus v2.0: The lclextensions and virtualtreeview packages are contained in the standard distribution of Lazarus because they are needed by the OnlinePackageManager. Go to "Package" > "Install/uninstall packages", select "virtualtreeview_package" in the right list, click "Install selection", then "Save and rebuild IDE".
  • Lazarus v2.2+ (or trunk): Like above, but the package and all units have been renamed to have a "laz." prefix, e.g. "laz.virtualtreeview_package" instead of "virtualtreeview_package" and "laz.virtualtrees" instead of "virtualtrees". The names of the registered components also begin with "Laz", e.g. "TLazVirtualStringTree" instead of "TVirtualStringTree". This was made to avoid a naming conflict when the user wants to install another version of VTV in addition to the built-in one.
  • Lazarus before v2.0, or VTV version other than v5.5.3.1 (in Laz v2.0 you will have to uninstall the built-in version first):
    • Download the LCL Extensions package and extract it to a directory (lazarus\components\lclextensions or other of your preference).
    • Download the Virtual Treeview package and extract it to a directory (lazarus\components\virtualtreeview or other of your preference).
    • Open lclextensions_package.lpk in LCL Extensions directory and click "Use / Add to project"
    • Open virtualtreeview_package.lpk in Virtual Treeview and click "Use / Install". Rebuild the IDE.


A comprehensive help file in .chm format(*) can be found within the GIT repository [1] in the subdirectory Help.
A tutorial and numerous code samples can be found in this forum VirtualTreeview Example for Lazarus, in the Demos Subdirectory of the VirtualTreeView GIT [2], and in the SVN of [3]

(*)Beginning with Windows 7, additional security measures were introduced for .chm Files, if you either download a .chm file directly via the browser (without going through a .zip file), or open the file from a network drive. The lock causes the problem that after opening the .chm file you will see only the table of contents, while the actual contents are missing. To manually release the lock use the Windows Explorer (Right Mouse Click - Properties - "Unblock"). This works with Windows 10 (4/2021) as well.

See also