Reduce File Size Autocad

See our Best PDF Practices webinar for some helpful tips on working with PDFs in CAD.

Issue

You plotted from AutoCAD to PDF, and the file size is too large. You need to reduce your PDF file size.

Cause

PDFs created from AutoCAD are a vector-based graphic file. The more vector information a PDF contains, the larger the file size. Your drawing likely includes a number of objects that use an excessive amount of vector information, which is causing the file size to balloon. The steps below will help you troubleshoot your drawing to identify and eliminate these problematic objects.

Solution

Need to reduce the file size quickly, and don't have time to troubleshoot your drawing for what might be causing the large file size? We recommend using a free website called SmallPDF.com to reduce the size of PDF files.

The following troubleshooting steps will minimize the file sizes of PDFs you create when plotting, but they're also AutoCAD best practices for optimal drawing performance. AutoCAD reads vectors in much the same way as PDFs do. These steps will improve your drawing's AutoCAD performance dramatically, giving a boost to your daily drafting speed.

  • Re: How to reduce file size in AutoCAD If the file is large and slowing your system down try putting individual components into blocks.
  • The Brep command erases that history, and the file size shrinks greatly.' Notes from Cadalyst Tip Patrol: When you use the Brep command, the history of the selected solid or solids is removed. That means the original objects cannot be selected, nor can they be modified.

Decrease PDF File Size: Print. Tip# 3620: By Mike Kurent: On 18-Apr-2011: 1. Rated By 1 users: Categories: Saving Files Software type: AutoCAD 2012 Rename File To: No Files to download. Use file reduction tools to shrink your files for archiving. Related CAD Tips. Keep an Eye on Autosave; Standardize When You Save and Close. Reduce File Size Autocad Lisp AutoCAD LT does not have the NETLOAD command which is needed to load the hotfix DLL file, which means the DGNPURGE command is not usable within AutoCAD LT. However, beginning with AutoCAD LT 2015, the enhanced PURGE functionality is included, so it is recommended to use version 2015 (or newer) to purge affected files.

1. Is this a colorized rendering plan?

If so, the colorization may be contributing to the large file size. Use the recommendations in the following articles to reduce your file size:

2. Is your drawing corrupt?

A corrupt drawing file can result in an excessively large PDF size. Follow our steps to clean your drawing and all Xrefs.

3. Does the drawing include extremely dense hatches?

If so, these hatches may be increasing the file size. For example, sand hatches use vector information for each dot. For a line-based hatch, each line adds more vector information. Try increasing the scale of your hatches to reduce PDF size.

Important: You may have some solid-looking hatches that are actually extremely dense hatch patterns. Switch these hatches to an actual solid pattern to reduce the file size.

4. Does the drawing use complex plant symbols?

As with hatches, the more lines, the larger the file size. Do you have a lot of shrub symbols using a detailed symbol? Try switching them out for our default simple symbols to see how the PDF size is affected. Tree symbols can also have this issue.

5. Does your drawing include lots of gradients?

If so, the gradients may also be causing the problem. We recommend avoiding the use of gradients in AutoCAD. Too many gradients can slow performance and make PDFs unusable.

See our steps for eliminating gradients from your drawing.

6. Does your drawing include a hatch with an overly complex boundary?

A hatch placed with a pickpoint can frequently pick up a convoluted boundary that you didn't intend. We've seen this type of boundary spike single pages up 25 MB or more for a single page PDF.

The example to the right shows an actual hatch that caused a 100MB spike in PDF file size over a multi-page PDF output, crashing AutoCAD and the PDF reader in the process.

If your drawing includes a hatch that fits this description, the solution is to draw polylines for the hatch boundary, then place the hatch using polyline boundary selections – for both the external border and any internal islands – rather than pickpoints.

7. Does your drawing include a hatch created with a corrupt PAT (.pat) file?

A corrupt PAT file can increase PDF file size. You can confirm a problem PAT file by placing that hatch in an otherwise-blank drawing. If you can replicate the huge PDF size from that drawing containing only that hatch, you'll know that hatch's PAT file is causing the issue.

After isolating and identifying the problem hatch, try using a different hatch pattern with a similar appearance instead.

8. Does your drawing contain large images?

PDFs generated from AutoCAD are always vector based rather than raster. If you reference large file size JPGs, PNGs, TIFFs, or other PDFs, the entire file size of those images will be included in the resulting plotted vector PDF.

You can address this issue by either:

  • Resaving the referenced images as much smaller files (we recommend using JPGs or PNGs), or
  • Using a PDF editor such as SmallPDF.com to flatten the PDF to raster

9. None of the above? Isolate the issue.

Because a large PDF size is almost always caused by an issue in your CAD drawing, isolating that issue is a great way to find out what is causing it.

If you've addressed all the common causes of large PDF files listed above (colorized plan/too many solid or gradient hatches, dense hatches, overly complex linework, problematic hatch boundaries, corruption, etc.), it's time to do some isolation troubleshooting.

9A.Save As to a new file name. You'll be deleting objects, and you don't want to save over your original file accidentally.

9B. Plot each layout separately (do not use the PUBLISH command). Identify which individual sheets have a file size issue. Try to determine what is the same about them. Free download trap boom vst plugin.

9C. Start systematically deleting items from a problem layout and then plotting to PDF after each test to see how it affects the file size.

How our technicians would diagnose this issue

Here's an example of how we located and diagnosed the problem hatch pictured above:

  • Isolated the hatch to a single layout, which we plotted to PDF at 25 MB.
  • Ensured the layout contained no gradients, not too many hatches, and no tiny-scale hatches.
  • Made sure the layout contained no other objects, turning on all layers.
  • Used CTRL+A to select all, and deselected what we could see. There was some text off in the distance outside Paper Space, but we plotted the PDF and determined the text wasn't the cause.
  • Deleted the viewport and plotted to PDF. The file size dropped from 25 MB to 125 KB, indicating that the issue was in the visible portion of Model Space rather than Paper Space.
  • Used the UNDO command to bring the viewport back, then deleted all hatches in Model Space instead (using the QSELECT command).
  • Plotted to PDF again, and the file size again dropped, meaning the issue was originating with a hatch.
  • Used the UNDO command again to bring back hatches, then used QSELECT to only delete all solid hatches. Plotted to PDF, and noted that the 25 MB file size remained, meaning the issue was originating from a patterned hatch.
  • Started deleting certain patterns and plotting each time, until the file size dropped, which isolated the issue to a single paver pattern.
  • At this point, just selecting the hatch made it clear it was the issue (convoluted boundary issue or corrupted PAT file).
  • However, if your drawing includes several instances or large areas of the problematic pattern, you could continue isolating to a certain region of the plan to find the bad hatch.

This isolation troubleshooting method works for a number of issues – not just PDF file size! If deleting the hatches fails to decrease the PDF size, move onto other object types. The solution will usually become clear once you're able to isolate the cause. If not, send us the following items in a technical support ticket:

  • The file with the isolated issue
  • A description of exactly what you're plotting so we can replicate the issue
  • A list of the troubleshooting steps you've already tried

Including all these items in your ticket will allow us to diagnose and address the issue more quickly so you can get back to work.

One of the advantages of choosing vector file types is that they typically are much smaller than their raster equivalents. This is because of the way that raster and vector files store information. A raster image stores color information for every single pixel, meaning they are often large in file size.

Vector files, meanwhile, contain paths. These are mathematical coordinates, and they tell the program how to display the graphical elements of the image. Far fewer paths are needed to make up an image than pixels, so vector files are typically smaller in size than their raster equivalents.

Typical CAD files used for architectural drawings can often smaller than a megabyte. Nonetheless, it’s clear that many users are still struggling with huge CAD file sizes. Why is this problem occurring, and how can it be fixed? Read on to learn more…

Does file size matter?

With the advent of the cloud and ultra-cheap file storage, many users might not worry about large file sizes. However, there are still plenty of times when smaller is better. It’s still important to slim down your CAD files if you’re going to share them via email.

Some users also face the problem of files which swell to sizes far larger than expected. Even if storage space is not an issue, CAD programs may slow down or even crash when dealing with very large file sizes. This is something which users will want to avoid.

The causes

If vector files are usually small in size, why do some CAD files weigh in at hundreds of megabytes? There are a number of reasons why your file size might spiral out of control:

  • Saving your file as a DXF. DXFs are ASCII files, which means that their paths are described in plain text. This is a relatively inefficient way of storing data, and can cause larger file sizes. Visit our article covering all the technical details of the DXF file format.
  • Raster images embedded in your CAD file. With DWG and DXF, users can embed raster images within a vector file. This can be a useful tool during post-processing, as the vector image can be overlaid on the original raster. However, as raster images are large in size, keeping this data embedded means bigger vector file sizes too.
  • Unnecessary vector data in your CAD file. This can include layers, blocks, or styles which are not needed to display the vector graphics.
  • Other unnecessary data and settings in your CAD file. As files are edited again and again, reams of settings and revision history can build up in the file. Much of this is not needed to display your vector image.
  • Technical issues, such as converting between different versions of a format.

The solutions

Autocad file too large

If your file size is too large, don’t despair. There are plenty of easy ways to cut your CAD file down to size.

  • If you’re sending a file by email, using standard compression methods (such as ZIP) might be all you need to do. Simply zip the file as you would any other file.
  • Switch from DXF to DWG. DWG is a binary file format, made up of 1s and 0s. This is a much more compact way of storing data than the ASCII text used by DXFs. DWGs are therefore typically smaller than DXFs. Visit our slideshow for more information about the differences between DXF and DWG.

Reduce Autocad File Size Online

  • Remove raster data from your CAD file. Once you are finished using your raster data, you should remove it. This is because of the large file size associated with raster images. Removing this data will help prevent your files from ballooning in size.
  • Remove unnecessary vector data. Removing blocks and layers which are not needed can help cut your files down to size. This can be done manually or by using purge controls in your CAD software.
  • Saving as a new image. This can help keep file sizes down by getting rid of unnecessary data and settings. Saving the image with a different file name after every edit also means you can keep track of revision history. Check out some of our top CAD file management tips for some ideas on how to store your images.

How To Reduce Cad File Size

Some files may simply be too complex, and there may be no way to reduce their file size. However, the above tips can help cut most CAD files down – so, why not try them out? If you have any tips of your own, submit them in the comments below!