This is a modification of confess.js's performance task which outputs (in JSON) webpage metadata and sizes + timings of every object; designed to be easily ingested into a database. Run it on a schedule to track website performance over time. Huzzah.
(Note: While the appcache and cssproperties tasks have not been removed, they have not been tested.)
> phantomjs confess.js http://stackoverflow.com performance
...will write, to stdout:
> {"elapsed":4579,"totaltime":"6493","totalsize":459165,"urls":[[1,72,105226,"http://stackoverflow.com/"],[2,114,45099,"http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"],[3,61,32827,"http://cdn.sstatic.net/Js/stub.en.js?v=5db0af4c6546"],[4,82,78045,"http://cdn.sstatic.net/stackoverflow/all.css?v=fd40bcfb3c2e"],[5,151,32115,"http://cdn.sstatic.net/img/share-sprite-new.svg?v=7966d6d82b78"],[6,138,872,"http://i.stack.imgur.com/5Uk7b.jpg"],[7,96,21745,"http://static.adzerk.net/ados.js"],[8,95,25393,"http://www.google-analytics.com/analytics.js"],[9,4291,7874,"http://edge.quantserve.com/quant.js"],[10,165,1900,"http://b.scorecardresearch.com/beacon.js"],[11,39,49178,"http://cdn.sstatic.net/Js/full-anon.en.js?v=7fcba0f54581"],[12,9,259,"http://i.stack.imgur.com/tKsDb.png"],[13,30,633,"http://i.stack.imgur.com/uE37r.png"],[14,30,19445,"http://cdn.sstatic.net/stackoverflow/img/sprites.png?v=3c6263c3453b"],[15,29,143,"http://cdn.sstatic.net/Img/mini-hero-bg.png?v=7f269bbbdb22"],[16,30,6906,"http://cdn.sstatic.net/Img/sprite-herobox.png?v=d173774f3a9f"],[17,65,14198,"http://cdn.sstatic.net/img/favicons-sprite16.png?v=d1fa29230270b12410ec5ae487182a5c"],[18,68,5243,"http://engine.adzerk.net/ados?t=1417153723450&request=%7B%22Placements%22:%5B%7B%22A%22:22,%22S%22:8277,%22D%22:%22adzerk1166068357%22,%22ATA%22:%5B17,2221%5D,%22Z%22:45%7D%5D,%22Keywords%22:%22undefined%22,%22Referrer%22:%22%22,%22IsAsync%22:true%7D"],[19,37,35,"http://www.google-analytics.com/r/collect?v=1&_v=j31&a=1387886923&t=pageview&_s=1&dl=http%3A%2F%2Fstackoverflow.com%2F&ul=en-us&de=UTF-8&dt=Stack%20Overflow&sd=32-bit&sr=1024x768&vp=400x300&je=0&_u=MEAAAAQAI~&jid=1882715993&cid=1298182927.1417153723&tid=UA-5620270-1&_r=1&z=1783626045"],[20,167,135,"http://stackoverflow.com/users/login/global/request"],[21,9,"-","http://b.scorecardresearch.com/b?c1=2&c2=17440561&ns__t=1417153723517&ns_c=UTF-8&c8=Stack%20Overflow&c7=http%3A%2F%2Fstackoverflow.com%2F&c9="],[22,11,3938,"http://static.adzerk.net/Extensions/adFeedback.js"],[23,24,1544,"http://static.adzerk.net/Extensions/adFeedback.css"],[24,10,"-","http://b.scorecardresearch.com/b2?c1=2&c2=17440561&ns__t=1417153723517&ns_c=UTF-8&c8=Stack%20Overflow&c7=http%3A%2F%2Fstackoverflow.com%2F&c9="],[25,42,2385,"http://static.adzerk.net/Advertisers/d936d243e9de4c989a6c95b031eb11d6.png"],[26,22,43,"http://engine.adzerk.net/i.gif?e=eyJhdiI6NDE0LCJhdCI6MTcsImJ0IjowLCJjbSI6MTg2NjI0LCJjaCI6MTE3OCwiY3IiOjY2Mjc5NSwiZGkiOiJiZGI1OGIzOTcxMTI0ZWFmODNiNjg2N2RiNmYwNTQxZCIsImRtIjoxLCJmYyI6Njg0NTIxLCJmbCI6NDEwMTgzLCJpcCI6IjE3My43MC40MS43MyIsIm53IjoyMiwicGMiOjAsInByIjoxNTY4LCJydCI6MSwic3QiOjgyNzcsInVrIjoidWUxLTJmNDJkNTFlNTFlMjRiZWRhYzcyZGFiYzdmOGZkYmVjIiwiem4iOjQ1LCJ0cyI6MTQxNzE1MzcyMzUxMSwiYmYiOnRydWV9&s=p93iDkPJiqBl0qo7yfQ0Tbw16-w"],[27,379,"-","https://stackauth.com/auth/global/read?request=hrWn6Nih%2Bm06A%2FAA2OF8UGv3lERS6qvCmldKt31boxPwNCRiPrnFC1yVMLDbnozt9CikL%2FaBApJ%2FnmYxiEmAOw%3D%3D&nonce=uwx4VAAAAABx03DQnBQUWw%3D%3D"],[28,70,1663,"http://clc.stackoverflow.com/j/p?d=hireme"],[29,51,2321,"http://cdn-careers.sstatic.net/careers/gethired/sidebar.min.css?v=c886aec35a12"],[30,106,"-","http://careers.stackoverflow.com/ad/i/fd83a3tNj3j-nCQk55BP4eS-2yFdC"],[31,"-","-","http://pixel.quantserve.com/pixel;r=1585351730;a=p-c1rF4kxgLUzNc;fpan=1;fpa=P0-1372948139-1417153727644;ns=0;ce=1;cm=;je=0;sr=1024x768x32;enc=n;dst=1;et=1417153727644;tzo=300;ref=;url=http%3A%2F%2Fstackoverflow.com%2F;ogl=type.website%2Cimage.http%3A%2F%2Fcdn%252Esstatic%252Enet%2Fstackoverflow%2Fimg%2Fapple-touch-icon%402%252Epng%3Fv%3Dfde65a5a78c6%2Ctitle.Stack%20Overflow%2Cdescription.Q%26A%20for%20professional%20and%20enthusiast%20programmers%2Curl.http%3A%2F%2Fstackoverflow%252Ecom%2F"]]
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