Not all formats can be compressed. Compression works like this. consider a picture, for example. On a bit level, it's formed by a bunch of zeros and ones (bits). Zeros occupy a physical space but can be overlooked (t're turned off bits), so, if we can take them out, you'll have an image that may lose or not resolution (lossy, or lossless formats), but much smaller than the original. This can be done for bitmaps, or Word documents. However, it can't be done for already compressed formats, such as JPEGs/JPGs, because you can't compress them much further. Therefore I don't think you can do it with a PDF (as itâs a compressed format already). However, you could try a couple of online solutions. PDFfiller.com - A Free Solution to all your PDF Problems Compress PDF files online for free. pdf compressor at DuckDuckGo
If you do use non-standard fonts in the PDF file, this may reduce the file size dramatically. See below for other alternative methods. If your PDF document is not the full version of the document that you downloaded, most PDF compression programs will add the embedded .pdf version of the document to make it appear more full. However, this does not mean that you should ignore that file altogether in order to reduce the PDF file size since it may contain important additional information, such as metadata or code comments. To compress the embedded .pdf version of your document to reduce its size, you are encouraged to set up an online version of the .pdf document with your program of choice and a “compressed” view. The online version can then read the embedded .pdf version of the document and display it. Since there will be text and the embedded .pdf.