One option is https://products.aspose.com/pdf/java/. Source: almost 2 years ago

I've totally used online conversion tools, so I'm not knocking them entirely (I've personally used online-convert.com for years now). Assuming no personal information, using them for a quick conversion for images or documents is great (check the settings!). Source: 11 months ago

Online-Convert for Web is a service that's trusted by many big brands and that I use for a lot of stuff, and it's worked very well for me. Only thing is you can't convert YT videos. Source: over 2 years ago

Add the extension "online-convert.com" to Chrome. When you run across an image like this right click and scroll down to the "file converter" option, then select "convert image to image". You'll have the option of converting it to many different image formats. You can also convert docs, pdfs, etc. It's a great free extension that I use often. HTH! Source: over 2 years ago

Gotcha.. they seem to be talking about coding a built in converter which would kinda suck and yeah all the issues mentioned there would prop up, I think using something already built is more ideal, there doesn't seem to be a usable open library so I was going down the road of using the online-convert.com api.. Depending on an external service also has it's cons, but gets you there with less code and dependencies. Source: almost 3 years ago

Each file (video/audio/ebook or whatever) has a MD5 hash which can be used to identify it. To change the hash, what you can do is change it to another format - Say if it is epub, AWZ, Lit or Docx - you can convert it to PDF or any other format using online converters like online-convert.com and then you can upload the coverted file. Source: about 3 years ago