Thank you, Edwin and Andreas! I do not have any sensitive information; it's just a presentation website, and I was looking for something that doesn’t load like a redirect.
Onload allows users to see the content for a fraction of a second, and if they press X (stop loading in the browser), they can stay on the page. In my case, this isn't an issue, but a proper redirect solution would be great for situations where companies want to add events (Christmas, summer deals) and typically prepare marketing campaigns in advance.