Newer cricut user here, so I’m far from an expert but I’ve found https://freesvg.org to have the best free selection of all the sites I’ve tried so far. Source: over 1 year ago

Contextually, what you're doing is fine. You're making personal-use invites for a kid's birthday party so I think it's admirable you're hoping for some casual free resources for use. Generally speaking, you're going to likely be looking for each source on a case-by-case basis because there isn't a single go-to large repository of commercial-quality, diverse free libraries of content. Some get close but they won't... Source: over 1 year ago

Freesvg.org and Vecteezy for illustrations/clip art. The cover of Project BRKN-Shackle uses two versions of the same “spy” graphic, and I then modified it/shifted the colors. I did even less work on Playdate Peril’s cover, just combining a couple illustrations. Source: almost 2 years ago

Not CorelDraw, but I think you can use this site for free SVG's. https://freesvg.org/. Source: almost 2 years ago

What you need is svg files, you can edit them using inkscape, which is free: https://inkscape.org/ There are lots of free public domain svgs here: https://freesvg.org/. Source: about 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