Simon Willison’s Weblog

Debugging HTTP headers

Tantek has released two new favelets for revealing HTTP information, using Mozilla’s ever useful Web Sniffer and Delorie’s HTTP Header Viewer. I spotted a similar tool on a recent trip to MozDev: LiveHTTPHeaders adds a “Headers” tab to the page information box in Mozilla 1.2, showing the full request and response headers used for the current page. It’s a very nice tool, but unfortunately does not yet work with Phoenix (the headers tab is added to the info box but the header information does not appear).