How to make a PDF searchable for free

Here are methods to make a PDF searchable for free.

1. Using Google docs
2. Upload your PDF to google drive.
3. Right click on the PDF and open with google docs.
4. This converts the PDF to text format.
5. Now you can search for text within this PDF.
6. You can also use an online services
   1. https://www.sandwichpdf.com/
   2. http://www.paperfile.net/
   3. https://www.onlineocr.net/
   4. https://www.sodapdf.com/ocr-pdf/
   5. https://ocr.space/