Reduce INDD file Size

[Sergio Venturini]

The way IndDesign works, increases the file size each saving time. File become unbearable and difficult to process, even in fast computers... It would be nice to have a chance to reduce the file size without recurring to the 'save as' method, that, sometimes doensn't work either. 

[Willi Adelberger]

1. Use save as instead of save
2. Save from time to time as IDML and open that and save as new INDD.
3. Never. embed images, link them as external assets.

[leo.r]

There could also be an issue with image metadata bloat:

https://community.adobe.com/t5/indesign-discussions/is-there-a-script-to-clear-indesign-metadata-red...

[Eugene Tyson]

I work on files with 300mb+ and never have much slow down, might switch Display Performance down to lowest, or middle, maybe that could help you, if you're only working on the text, there's no need to display the images. 

And I work with files with the images always embedded, never have an issue with this workflow.

When I switch to overprint preview or high quality preview - then I get a bit of slow down. 

Just some tips to get you going when file sizes are unavoidable.

[tonks_the_auror]

The OP would like to be able to reduce file size without using "save as."

What OS?

What version of InDesign

Working locally or on a server or the cloud?

Like Eugene, I work on large files— on my ageing MacBook Pro—and have no problems with files becoming "unbearable and difficult to process." 

Also, I use the "save as" method at certain intervals and that works for me.

[Sergio Venturini]

Hi! MacOs Sequoia 15.0 here installed in a MacStudio 2022 with 16gb RAM.

Latest version of InDesign, working files locally.

The Save as method doesn't seem to reduce the file size at all, besides PNG original files weight less than 1MB. 

IDML files can't be opened by InDesign, as a message appears to tell me those files are not compatible (?) or a plugin is missing.

[Willi Adelberger]

The message with IDML files comes only, if you try to open an INDD file in an older version. 

[Willi Adelberger]

But embedding images will definitely increase the file size. For computer with not high TAM it is the way to go. 

[Eugene Tyson]

My experience is that slow files rarely have anything to do with file size. Whether an image is embedded or linked, the size of the file itself usually isn’t what causes the lag.

What tends to slow things down is how InDesign processes graphics. The Display Performance setting makes a huge difference I keep it on the lowest setting while editing text, then only switch to Overprint Preview or High-Quality Display when I need to check the images.

The OP is linking lag to file size, but in practice that’s not the main factor. Adobe’s own documentation and community reports point to image rendering, preview modes, live preflight, cross-references, fonts, and live screen drawing as bigger culprits.

File size can contribute in extreme cases like very large or numerous high-resolution images but it’s not usually the bottleneck.

In short, the real slowdown comes from InDesign’s handling of image display and rendering, which has always been on the sluggish side.

As well as image display (embedded or not) the OP could try these
Turn off live preflight
Check cross-references

Fonts are all ok
and turn off live screen drawing in the preferences

[rob day]

Hi @Sergio Venturini , The 3.7 GB file size you mentioned in your other thread is not normal even if you were embedding the 3 or 4 images. In addition to the thread @leo.r linked to with the script cleaner, there’s this, which goes into more depth on the bug:

https://community.adobe.com/t5/indesign-discussions/my-whole-hypenation-disappeared/m-p/15524052#M63...

[rob day]

Sorry here is the metadata link:

https://community.adobe.com/t5/indesign-discussions/file-size-is-too-big/td-p/9370587#10084949

[Mike Witherell]

Sergio,

In my experience, the biggest factor in file-bloat is the mistake of File > Place -ing graphics without first opening them in Photoshop, adjusting the size/and/ppi to match the expected use size on the page in InDesign. In other words, a lot of images default to 72ppi. They benefit when you re-size them to the designed physical size, but also set the ppi to (usually) 300 ppi (common for printing). Doing this first, and then import/Place into InDesign allows InDesign to create much smaller image previews for the linked file. This directly affects file bloat.

Many say it is better to leave the original scan alone and do not down-sample it, and I agree with that. But you can still freely change the Image > Image Size ppi to something higher like 300 instead of 72ppi. This doesn't resample the image, allowing you to keep the original pixels. There is no image degradation; yet InDesign experiences less file bloat.

The other commenters have already also mentioned doing a Save-As from time to time. They have also mentioned doing an export to .IDML and re-opening the .IDML to a new, cleaner, InDesign file. File > Placing; not drag-n-dropping; not embedding; all those are good practices, too.

[Willi Adelberger]

I think it is insane to open any file in Photoshop before placing it in InDesign as you will destroy many parts of the content. Let any file be original linked.

[Mike Witherell]

Really? What are you seeing getting destroyed?

[Willi Adelberger]

Vectors are rasterized, Layer Comps and cutting paths. 

[Mike Witherell]

Oh I see. Bear in mind that I wasn't suggesting opening vector art in Photoshop. I was referring to bitmap, ie, pixel-based photo assets. 

[Sergio Venturini · Accepted solution]

I remade the whole file. I would state that I think you are right. Placing images solved the whole thing, but also, It would be great to state that having placed low size files with huge resolution (that was my mistake) somehow made InDesign process the files in a way the indd file got giga sized. Then, the way InDesign manages old versions embeded in the same project file, made impossible to correct this in future versions, even deleting the images and placing them instead. 

Thank you all, @Willi Adelberger @Mike Witherell @rob day @Eugene Tyson @tonks_the_auror the problem has been solved.

[Eugene Tyson]

Were you copying and pasting them into InDesign? 
That's different to File>Place then Embed via the Links panel.

If you're copying and pasting directly to InDesign - don't - as you probably know now - use File>Place

Anyway glad it's sorted and you've loadsa tips to get you going in better workflows.