Indesign exported PDF is HUGE

[Nelladel]

I had a 50MB indesign file (idk why it was this big). I managed to reduce the file size to 14MB by replacing the psd links with TIFF files. However, the exported pdf (for print) is still 30MB. I can't imagine the reason behind it. I use the same export settings as always, I use no embedded links, but still, the pdf is twice the size of the indd file. 

[BobLevine]

The information provided is pretty much irrelevant. The size of an INDD file has no direct correlation on the size of the PDF.

So, please take a step back and give us some important info:

1. Version of ID and operating system
2. PDF Export settings
3. What the purpose of the PDF is (screen, press, etc)

BTW, the easiest way to make an INDD file smaller is to use the save as command once in a while and save the file over itself. This removes all kinds of extraneous data.

[Nelladel]

Hello!
InDesign version is 19.3.
The purpose is press. It's an A4 one page long file. I used the save as method, didn't help much, but now the key issue is the pdf size. 

[Robert at ID-Tasker]

@Nelladel 

Based on the screenshot from the Links pallet - size of your PDF is pretty much the sum of links sizes...

[Nelladel]

Okay, but when I used way bigger links (at the beginning of this process some psd links were 200+ MB) the final pdf was the same size as now. That I find weird and don't really understand.

[Robert at ID-Tasker]

Okay, but when I used way bigger links (at the beginning of this process some psd links were 200+ MB) the final pdf was the same size as now. That I find weird and don't really understand.

By @Nelladel

As per your 1st screenshot - you have a 450 downsample threshold..

Please check Links panel for your links:

If Effective PPI is higher than your threshold - link will be downsampled.

[Nelladel]

I know this, that's the point of compressing, right? Sorry if I'm slow, but I don't understand the problem. Isn't the downsampling supposed to reduce the file size? Even if I set the treshold to 300dpi, it barely does anything to the file size. 
There's a high possibility that my basic understanding of this compressing/exporting situation is very limited, so... yeah, there's that.

[Willi Adelberger]

1. I see that you wrote rasterize to several file name. Does this mean that they were in its original state vectors?
2. If it is so, what file type have they been originallly?
3. If so, why have you rasterized them?

[Nelladel]

Those links were psd files with several layers, smart objects, adjustment layers etc... 
I tried rasterizing them because some of the links were 100-400 mb. This way, I managed to reduce the links to an acceptable level, but it had little to no effect on either the indd file size, or the pdf file size. 

[BobLevine]

No, they wouldn't. The InDesign file is using previews which don't change all that much no matter what you do and the PDF is using a flattened version that has been downsampled.

In short, if this is for press work, you're really worried about nothing.