How would I create an over-sized graphic?

I am designing a “recommendation” chart. My design will not fit on a standard slide/doc/etc. I want it to be a pretty large image in which people can zoom in to look a different parts of it. How can I make this, or what type of software (free or online) can I use to accomplish this? Thank you in advance.

That depends on what you’re trying to accomplish and in what environment it will be viewed. When designing a website, for example, this problem would be handled in a completely different way than it might when designing something for a kiosk or a mobile app.

Maybe something as simple as a PDF would address your problem. In a layout program, like InDesign, you could design a page to be viewed at a size typical for a computer display. Within that page, however, you could have additional, smaller content that would require the person viewing it to enlarge the page and zoom in on it. Save that layout as a PDF file, and it’s reasonably intuitive for the end user to zoom in to see details. Most designers would try to avoid this approach — preferring, instead, to separate the content over multiple pages.

You mentioned free or online, though. Unfortunately, I don’t have many suggestions that involve doing a good job using only free tools.