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Reduce file size and eliminate unwanted drawing settings with the WBLOCK command

Several people have asked about inexplicably large files.

Kerry Overall wrote me,

I’ve seen unusually large CAD .dwg files. I had the same problem when a colleague stumbled onto a solution that greatly helped me. Open the drawing….wblock,   click on “Entire Drawing” and save it. I had a simple file that was 73mb and by doing this it reduced it down to 3mb.  And quickly , too.

The WBLOCK command writes (saves) the objects in a drawing as a new drawing. You can specify specific objects or the entire drawing.

A bonus is that you lose many settings in the current drawing. You can therefore use this technique to troubleshoot problem drawings that don’t behave the way you want them to. It’s often hard to ferret out the settings that might be causing the problem — such as system variables — so moving the objects to a new drawing can be an easy fix.

Here are the steps to reduce extremely large Autocad file with wblock command:

  1. If you want, you can select objects in advance.autocad-tips-reduce-file-size-wblock-1
  2. Type WBLOCK on the command line or choose Insert> Block Definition panel> click the Create Block drop-down arrow and choose Write Block. (It’s easiest to just type it on the command line.) The Write Block dialog box opens. If you pre-selected objects, the number of objects appears in the Objects section of the dialog box.
  3. To write the entire drawing, choose Entire Drawing at the top.
  4. You can choose a base point. If you want to be able to insert the drawing (or the selected objects) using a base point on one of the objects, for example, click the Pick Point button and specify the base point.
  5. In the Objects section, you can choose to retain the objects in the current drawing, convert them to a block, or delete them from the drawing.
  6. In the Destination section, click the Ellipsis button and browse to the location where you want to save the new drawing. Give the drawing a name and click the Save button.
  7. If desired, choose units from the Insert Units drop-down list. You can choose Unitless. You can even choose light years or parsecs if you’re thinking really big!
  8. Click OK.

If you did these steps to make your drawing smaller, go into Windows Explorer and check the size of the original and new drawings.

There are also many useful additional tips in the comment section. Go and check it out if this tip doesn’t work for you.

What other techniques have you used to reduce the size of AutoCAD drawings? Leave a comment and share with others!

Ellen Finkelstein

24 comments to Reduce file size and eliminate unwanted drawing settings with the WBLOCK command


    i’m having a problem now my i drawn large drawing the but i did not set a limits,
    why the object are shrank and when plot is not expanding the object are to small i plot it on A0 the object still small i tried also to scale but i cannot get the exact scale.
    thanks in advance

  • Dirk

    Things to keep in mind when saving drawings with unexplanable size is to keep an eye on the block index and possebly the sometimes unseen content in the layout tabs.
    Purge and autit are essential commands, and don’t forget to select “purge zero length and empty objects” to get those as well.
    And another small but sometimes speed increasing setting is under the “saveas” window, select tools, dwg options, and in the drop down menu “layer and spatial”.
    That one might not be the most speed saving for the basic drawing itself, but it does help when it’s used as a (clipped) xref.

  • Steve

    Dirk thanks for the tip on the “Layer & Spatial” I didn’t even know it existed. My company sometimes gets “clip happy” and often causes many errors in doing so. This may assist with that. PS. Is there a system variable for this?

  • kevinS

    lost the ability to see dimensions as drawing.. in Autocad. drawing a rectangle or edit it the dimens would show and you can tab to what you want to change and set it… that is gone and can not find how to get it back.
    Any ideas?

  • Kevin, I want to pass this on, but don’t understand the question. Can you rephrase it?

  • Dirk

    I think i might have found the problem KevinS is referring to, it might be the “Dynamic Input” button that can be toggled with the F12 key. That one modifies the behaviour of the input when you draw lines or other objects.

  • HI Ellen,
    I wanted to add that sometimes there are certain objects in a dwg file that can’t be purged, wblocked, etc. If you have a situation where your drawings is more than a few meg in size … it really should be much smaller, even in today’s CAD. So try this! First turn on and thaw, and unlock all the entities that you want to keep. Next type COPYBASE, use 0,0 and manually select all the entities that you can see with WindowPolygon or WindowCrossing selections. The trick here is not to use ALL or SELECT ALL selection methods because we are trying to only select visible and real objects! Next, open another instance of AutoCAD, and in Drawing1.dwg type paste. Next type SAVEAS and then compare the two drawing files. Many times, I have seen a 12 meg drawing in Civil3D go to 0.5 meg. And remember that a smaller drawing is more efficient, faster, and easier to email… so don’t knock yourself out trying to send a 12 meg dwg by email when it’s not necessary! The downside is that you loose all your settings (an you should have a way to put them all back). The upside is that you may have reduced your file size by as much as 10X. And since this trick relies on the QNEW setting, make sure that drawing is not bloated as well, because you will never get the file size smaller than your QNEW drawing.



  • Graig

    purge command is much better

  • phani kumar

    thank you so much,
    it worked on my dwgs,i follow the above 8 steps but i selected the entire drawing.
    really its amazing for actual file size is 103.067kb(100MB) is changed to 7.58MB.

  • Tim

    Usine Acad LT 2013… I have wBlocked a 12 meg dwg. now it is like 1.7 meg. The problem is the file is now saved as the version of Acad LT I am using. The customer wants the file saved down as 2000. After wBlock,opening that file and saving as an older Acad version the file is back to 12 meg.

    Anyone have an answer to why this is happening.


  • JAY


  • Edwel

    In my side the WBlock and purge command is not working on my Autocad files, still large file, there is other way of reducing large files can you help me how to reduce. please, please send your answer at my email

  • very useful. Many thanks.

  • olaseni

    Wow thanks a lot the wblock really helped .from 53mb down to 11.2mb

  • Teja

    Hi Ellen,

    I have tried the above “WBLOCK” command, but the file size increased by 1MB from 48MB instead of reducing it. Please tell me if there are any alternate commands.


  • Inba

    How to reduce Autocad drawing file size



  • P. de Waal

    Some of my tricks to reduce file size:

    1.) Put all architecture on a single layer, isolate, then join (multiple times) all the lines to polylines to reduce number of objects. This greatly reduces size.
    2.) type NU (qselect), select all points and delete.
    3.) type NU (qselect), select lines <= 10mm in length, and delete all. You can even try <= if you need to. Repeat this step with polylines.
    4.) type B (block definition), search for any blocks that only appear once, burst/explode them and join all lines. For any other blocks that appear multiple times, edit them and join all the internal lines.
    5.) NEVER use overkill, except for removing duplicated blocks. Mostly it increases the amount of objects, unless you have a REALLY inefficient drawing.
    6.) use LSPs such as strip mtext, attribute definition to text etc. to clean text and set all to STANDARD , Arial, Text Size 0.
    7.) clean up all unused scales

    Can't think of any more that I typically use to clean drawings for MEP purposes, but there are a lot more tricks to use

  • P. de Waal

    Some additional steps:

    8.) use -EXPORTTOAUTOCAD to convert all objects to ACAD types.
    9.A) use PURGE, -PURGE /regapps and AUDIT w/error fixing regularly
    9.B) you can make a button that does “^C^C-purge;a;*;n;-purge;r;*;n;audit;y;” to run purge,-purge and audit with a single click.

    Step 8. is probably the most useful. Unless your drawing comes directly from autocad, with only autocad entities, this WILL greatly reduce your file size without losing any data

  • khwaja

    wblock worked and saved my day… thanks man.

  • amrut

    I want to delete unwanted data from file….I am trying to make wblock to reduce size & clean the file.
    but having problem getting below massage

    “Missing DXF group code: 2
    Invalid or incomplete DXF input — drawing discarded.”

    Please advise somebody…

  • Reynaldo Bonilla

    Txns, it works perfectly in my drawings.

  • Patricia Seyford

    I use WBlock pretty regularly because it gets rid of all of the unwanted linetypes in a drawing. I find this helpful when drawings have been reused. However, it will get rid of layer states. Also, today I used it and my 0,0,0 shifted and I had to go into my xref’ed drawings to realign it with the content.

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