PURGE Command in AutoCAD

AutoCAD Purge Command Access

Introduction to PURGE

The PURGE command in AutoCAD removes unused items and unnecessary data from a drawing. As a drawing is created and edited, it can accumulate unused block definitions, layers, linetypes, text styles, dimension styles, and other information that is no longer needed. PURGE provides a way to identify and remove this unused data.

Purging a drawing can make its contents easier to manage and may reduce the size of the DWG file. It is particularly useful after importing or copying information from other drawings, before distributing or archiving a drawing, and when cleaning an existing drawing before using it as the basis for a new project or template.

PURGE does not simply erase visible drawing objects. Instead, much of its work involves removing definitions and other information stored within the drawing database that are no longer being used.

What Does PURGE Do in AutoCAD?

An AutoCAD drawing contains considerably more information than the objects you can see in Model Space or Paper Space. The DWG database also stores definitions for layers, blocks, linetypes, text styles, dimension styles, MLeader styles, table styles, materials, and many other drawing resources.

These definitions can remain in the drawing even after the objects that originally used them have been erased.

For example, suppose you insert a block named DESK into a drawing. AutoCAD stores the DESK block definition in the drawing database and creates a block reference that you can see in the drawing. If you later erase that block reference, the DESK block definition can remain in the DWG even though there are no longer any DESK blocks visible in the drawing.

PURGE identifies definitions and other data that are no longer required and allows you to remove them.

The PURGE command identifies unused drawing data that can be removed from the DWG file.

This becomes increasingly useful as drawings are reused. Copying objects from other drawings can bring layers, linetypes, styles, and block definitions along with them. After years of editing and reuse, a drawing can contain a surprising amount of information that has nothing to do with its current contents.

How to Purge an AutoCAD Drawing

When you start PURGE, AutoCAD opens the Purge dialog box. The Purgeable Items view displays categories of named objects that AutoCAD has determined can currently be removed from the drawing.

To purge a drawing:

1. Start the PURGE command.
2. Make sure Purgeable Items is selected.
3. Expand the categories to review the items that can be removed.
4. Select the individual items or categories you want to purge.
5. Select Purge Checked Items to remove the selected items, or use Purge All to remove all eligible unused items.
6. Confirm the items if Confirm Each Item to Be Purged is enabled.

You do not have to purge everything. The tree structure lets you expand individual categories and select specific definitions for removal.

Expand categories in the PURGE dialog to review and select individual unused drawing definitions.

This is useful when cleaning a drawing that contains standards you intentionally want to retain. An unused definition is not necessarily an unwanted definition.

For a drawing you know well and simply want to clean thoroughly, Purge All provides a faster approach. For an unfamiliar drawing, reviewing the available items before removing them is generally the more cautious approach.

What Can PURGE Remove?

PURGE can remove many types of unused information from a drawing. Common purgeable named objects include:

Item	What PURGE Can Remove
Blocks	Unused block definitions
Layers	Unused layers
Linetypes	Unused linetype definitions
Text Styles	Unused text styles
Dimension Styles	Unused dimension styles
MLeader Styles	Unused multileader styles
Table Styles	Unused table styles
Materials	Unused material definitions
Groups	Unused group definitions
Visual and View Styles	Unused style definitions

AutoCAD can also purge additional types of named objects beyond those shown in this table.

The important word is unused.

PURGE does not normally remove a definition simply because you do not want it. AutoCAD must determine that the definition is no longer required by the drawing.

Blocks provide a good example.

Block definitions can remain in a DWG after their visible block references have been erased.

Erasing every visible insertion of a block does not necessarily remove its definition from the drawing database. Once the block no longer has any references or other dependencies preventing its removal, its definition can become available in PURGE.

The current PURGE dialog can also remove certain unnamed objects, including zero-length geometry, empty text objects, and orphaned data. Zero-length geometry includes objects such as lines, arcs, circles, and polylines that have no length. Empty text objects include TEXT and MTEXT objects containing spaces but no actual text. Autodesk notes that PURGE does not remove these unnamed objects when they are inside blocks or on locked layers.

Why Won't AutoCAD Let Me Purge an Item?

If a layer, block, linetype, or other definition does not appear in the list of purgeable items, AutoCAD usually has a reason for keeping it.

The definition may still be referenced somewhere in the drawing.

For example:

• A layer may still contain one or more objects.
• A block definition may still have a block reference in the drawing.
• A block may be nested inside another block.
• A linetype may still be assigned to an object or layer.
• A style may still be referenced by another object or definition.
• The item may be a required default object that AutoCAD does not allow you to remove.

The PURGE dialog includes a Find Non-Purgeable Items view specifically for investigating this problem. It lists named objects that cannot currently be purged. Selecting an item can display information about why AutoCAD considers it non-purgeable. For many items, AutoCAD can also provide details about the objects using the definition and can select those objects in the drawing.

Find Non-Purgeable Items helps identify why a layer, block, style, or other definition cannot be removed.

This makes PURGE useful for more than deleting unused definitions. It can also help diagnose why a definition you thought was unused is still present.

If a layer refuses to purge, for example, don't assume PURGE has failed. Check Find Non-Purgeable Items. There may still be an object on the layer or another dependency keeping the layer in use.

Purging Nested Items

Drawing definitions can depend on other drawing definitions.

Consider a block named OFFICE that contains another block named CHAIR. Even if there are no OFFICE block references remaining in the drawing, the OFFICE block definition itself still contains a reference to CHAIR.

That creates a nested relationship.

The Purge Nested Items option allows AutoCAD to remove unused named objects even when they are contained within or referenced by other unused named objects. Autodesk specifies that this option applies when purging All Items, Blocks, or using Purge All.

Purge Nested Items allows unused definitions referenced by other unused definitions to be removed during cleanup.

Without nested purging, removing one unused definition can make another definition eligible to be removed afterward. This is why repeatedly running PURGE has historically been a common AutoCAD cleanup technique: removing one level of unused information can expose another.

The current PURGE dialog makes this process easier by providing the Purge Nested Items option.

When Should You Purge a Drawing?

PURGE can be useful throughout the life of a drawing, but there are several situations where it is particularly valuable.

Before creating a template. 

A drawing that will become a DWT should contain the standards and resources you intentionally want available in future drawings, not years of accidental leftovers from previous projects.

After copying or importing substantial content. 

Bringing information from outside drawings can also bring unwanted layers, blocks, styles, and linetypes.

After major revisions.

Removing large portions of a project can leave definitions behind that are no longer needed.

Before sending a drawing to someone else. 

Cleaning unnecessary content can make the delivered DWG easier for another person to understand and manage.

Before archiving a project. 

Removing genuinely unnecessary information can leave a cleaner final drawing.

When troubleshooting an unusually cluttered drawing. 

PURGE can help identify and remove accumulated data and may reduce an unnecessarily large DWG file. Autodesk also includes PURGE among its drawing-cleanup tools for drawings experiencing file-size or performance problems.

There is no need to purge a drawing after every editing session. Use the command when cleanup provides a practical benefit.

PURGE vs. AUDIT

PURGE and AUDIT are both commonly associated with drawing maintenance, but they perform different jobs.

Command	Primary Purpose
PURGE	Removes unused drawing items and data
AUDIT	Evaluates the integrity of the drawing database and corrects certain errors

PURGE is primarily a cleanup command. AUDIT is primarily an error-checking and repair command.

A drawing can contain hundreds of unused definitions without being corrupt, and a drawing can contain database errors even if there is nothing useful to purge. When troubleshooting a problematic DWG, the two commands may be used together because they address different aspects of drawing maintenance. Autodesk likewise identifies PURGE and AUDIT as separate drawing-maintenance utilities.

PURGE Best Practices

PURGE is generally straightforward, but the fact that AutoCAD identifies something as unused does not necessarily mean you should remove it.

This distinction becomes especially important with templates and office standards.

A master drawing or template might intentionally contain layers for objects that have not yet been drawn, block definitions that will be used later, predefined text and dimension styles, or other resources intended for future work. Those definitions may currently be unused while still serving a legitimate purpose.

Before aggressively purging an unfamiliar drawing, understand what the drawing is being used for.

For ordinary project drawings, PURGE can be an excellent way to remove accumulated leftovers. For master templates and standards drawings, use more judgment.

Saving the drawing before performing extensive cleanup also gives you an easy way to return to the previous version if you later discover that you removed something you wanted to keep.

PURGE is an important AutoCAD maintenance tool, but it works best as part of good drawing management rather than as a replacement for it.

Related Commands

Command	Description
-PURGE	Provides command-line access to purging options and can purge specific categories of unused drawing data.
AUDIT	Checks the integrity of the drawing database and corrects certain errors.
RECOVER	Attempts to repair a damaged drawing while opening it.
LAYER	Creates and manages drawing layers and their properties.
BLOCK	Creates block definitions from selected drawing objects.

The command-line -PURGE command is particularly useful for advanced cleanup and automation. It also provides access to purging registered applications (RegApps), which Autodesk documents as a command-line-only purge option.

Frequently Asked Questions