How to use Chrome's network debugger with redirects

416
votes

The Chrome network debugger gives me a great view of all the HTTP resources loaded for a page. But it clears the list whenever a new top-level HTML page is loaded. This makes it very difficult to debug pages that automatically reload for one reason or another (running script or 300 responses).

Can I tell Chrome not to clear the network debugger when a new top-level page is loaded? Or can I go back and look at the previous page's network resources?

Or can I somehow force Chrome to pause before loading a new page when I don't control the page I'm trying to debug that's doing the redirecting? It's part of an OpenID dance that's going awry, so the combination of SSL and credentials makes it extremely difficult to debug with command-line tools.

4
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How did this duplicate get more upvotes than the one posted 1 month before it? stackoverflow.com/q/10703944/632951 – Pacerier
@Pacerier The one you linked doesn't appear to be posted by you, but the reasoning is likely that it doesn't have "Chrome" in the title. When people are looking for something related to Chrome their search usually includes the keyword Chrome. "Google Developer Tools" is incredibly ambiguous. – Joel Mellon
gist.github.com/InstanceOfMichael/f6a509b84fe82a718816 – Diosney

4 Answers

584
votes

This has been changed since v32, thanks to @Daniel Alexiuc & @Thanatos for their comments.

Current (≥ v32)

At the top of the "Network" tab of DevTools, there's a checkbox to switch on the "Preserve log" functionality. If it is checked, the network log is preserved on page load.

Chrome v33 DevTools Network Tab: Preserve Log

The little red dot on the left now has the purpose to switch network logging on and off completely.

Older versions

In older versions of Chrome (v21 here), there's a little, clickable red dot in the footer of the "Network" tab.

Chrome v22 DevTools Network Tab: Preserve Log Upon Navigation

If you hover over it, it will tell you, that it will "Preserve Log Upon Navigation" when it is activated. It holds the promise.

202
votes

I don't know of a way to force Chrome to not clear the Network debugger, but this might accomplish what you're looking for:

  1. Open the js console
  2. window.addEventListener("beforeunload", function() { debugger; }, false)

This will pause chrome before loading the new page by hitting a breakpoint.

35
votes

Another great solution to debug the Network calls before redirecting to other pages is to select the beforeunload event break point

This way you assure to break the flow right before it redirecting it to another page, this way all network calls, network data and console logs are still there.

This solution is best when you want to check what is the response of the calls

Chrome beforeunload event break point

P.S: You can also use XHR break points if you want to stop right before a specific call or any call (see image example) XHR break point

26
votes

Just update of @bfncs answer

I think around Chrome 43 the behavior was changed a little. You still need to enable Preserve log to see, but now redirect shown under Other tab, when loaded document is shown under Doc.

This always confuse me, because I have a lot of networks requests and filter it by type XHR, Doc, JS etc. But in case of redirect the Doc tab is empty, so I have to guess.