Ask HN: Why does 'View Source' issue a new HTTP request?

173 points

9 years ago

I've noticed that both Firefox and Chrome issue a new HTTP request when you view the source for a web page that you've already loaded. It's particularly annoying when the page itself is slow to load or if it won't load at all.

Why is that? Wouldn't they have the existing source for the originally received page cached already? Is it based on Cache-Control headers?

This has been on my mind for a while (usually comes up when looking at what's behind slow web apps) and came up again with Piwik on the front page[1]. Their website was semi-down (HN hug of death) but eventually loaded. I wanted to see what their GA equivalent tracking code looks like but the page failed to load as rather than showing the cached copy, it tried to fetch a new one.

[1]: https://news.ycombinator.com/item?id=13210195

93 comments