Toolkit for web developers.

When develop a website or web app, it is not easy make a great experience for each browser or device that uses it.  It is important to have in mind some general topics like response time, availability and consistency

As Gomez define in their Best of the Web Report (2009):

Response time measures the end-to-end time elapsed while downloading each Web page or the entire multistep transaction process. This includes the base HTML page and any referenced objects, third-party content, JavaScript and Cascading Style Sheets and other Web content. The reported metric represents the average time required to download the homepage or execute the multistep transaction without factoring in user latency.

Availability measures the percentage of successfully completed tests out of total test attempts for the period. Availability rates are dependent upon a number of variables including the ability of our testing agent to access the Website, its ability to process a transaction without error, and its ability to download each step of the transaction within a reasonable 60-second time frame. Reported availability rates do not include errors related to the Gomez measurement system or scripting problems.

Consistency measures the standard deviation of the response times of successful tests. The goal is to have a low number (in seconds), which indicates how consistent the response time is each time a user visits a Website. Highly variable response times (in seconds) indicate inconsistent performance that may be caused by poor Website performance as measured across diverse geographies, issues with Internet peering or an under-powered technical architecture which leads to slowdowns during periods of peak traffic.

In this post I show some tools that help us to improve our work as developers, it covers tools for debug, analyze, document, minify, monitor and test the apps.

Browser Tools

The browser tools are plug-ins or tools that are directly embedded in the browsers, the list with the original description as it appears on the website of each tool.

Firebug

http://getfirebug.com/

Firebug integrates with Firefox to put a wealth of web development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.

• Inspect and edit HTML
• Tweak CSS to perfection
• Visualize CSS metrics
• Monitor network activity
• Debug and profile JavaScript
• Quickly find errors
• Explore the DOM
• Execute JavaScript on the fly
• Console logging for JavaScript

Firebug Lite

http://getfirebug.com/firebuglite

Compatible with all major browsers: IE6+, Firefox, Opera, Safari and Chrome, You can extend it and add features to make it even more powerful.

YSlow

http://developer.yahoo.com/yslow/

YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages (http://developer.yahoo.com/performance/rules.html).  YSlow is a Firefox add-on integrated with the Firebug web development tool. YSlow grades web page based on one of three predefined rule set or a user-defined rule set. It offers suggestions for improving the page’s performance, summarizes the page’s components, displays statistics about the page, and provides tools for performance analysis, including Smush.itâ„¢ and JSLint.

Smush.it

http://www.smushit.com/ysmush.it/

Image optimization is an art few have mastered. Useful image editing tools exist that allow images to be edited to reduce their file size while retaining image quality. Using these tools is a good start for optimizing images, but more can be done using advanced tools like Smush.it.

Smush.it uses optimization techniques specific to image format to remove unnecessary bytes from image files. It is a «lossless» tool, which means it optimizes the images without changing their look or visual quality. After Smush.it runs on a web page it reports how many bytes would be saved by optimizing the page’s images and provides a downloadable zip file with the minimized image files.

Smush.it is included with YSlow and is no longer available as a separate download. Download YSlow now to get Smush.it and start saving bytes on image files.

Page speed

http://code.google.com/speed/page-speed/

Page Speed is an open-source project started at Google to help developers optimize their web pages by applying web performance best practices. Page Speed started as an open-source Firefox/Firebug add-on and is now deployed in third-party products such as Webpagetest.org, Show Slow and Google Webmaster Tools.

Page Speed is a family of tools for optimizing the performance of web pages.

• The Page Speed Firefox/Firebug add-on allows you to evaluate the performance of your web pages and to get suggestions on how to improve them.
• The mod_pagespeed Apache module automatically rewrites pages and resources to improve their performance.

Web Inspector

The Web Inspector from safari, gives you quick and easy access to the richest set of development tools ever included in a browser. From viewing the structure of a page to debugging JavaScript to optimizing performance, the Web Inspector presents its tools in a clean window designed to make developing web applications more efficient. To activate it, choose Show Web Inspector from the Develop menu.

• Choosing Safari Menu Option
• Choosing Preferences…
• Choosing the Advanced Tab
• Enabling “Show Develop menu in menu bar“

Speed tracer

http://code.google.com/webtoolkit/speedtracer/

Speed Tracer is a tool to help you identify and fix performance problems in your web applications. It visualizes metrics that are taken from low level instrumentation points inside of the browser and analyzes them as your application runs. Speed Tracer is available as a Chrome extension and works on all platforms where extensions are currently supported (Windows and Linux).

Using Speed Tracer you are able to get a better picture of where time is being spent in your application. This includes problems caused by JavaScript parsing and execution, layout, CSS style recalculation and selector matching, DOM event handling, network resource loading, timer fires, XMLHttpRequest callbacks, painting, and more.

Chromium Benchmarking Extension

http://www.chromium.org/chrome-benchmarking-extension

The Chromium Benchmarking Extension is a quick-and-dirty way to test page load time performance within Chrome.

• Can clear the cache between each page load
• Can clear existing connections between each page load
• Works with both SPDY and HTTP
• Measures time-to-first-paint, overall page load time KB read/written, and several other metrics
• Can compare performance between SPDY (http://www.chromium.org/spdy)  and HTTP

Internet Explorer Developer Toolbar

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=95e06cbe-4940-4218-b75d-b8856fced535

The Internet Explorer Developer Toolbar provides several features for exploring and understanding Web pages, is not compatible with Internet Explorer 8. These features enable you to:

• Explore and modify the document object model (DOM) of a Web page.
• Locate and select specific elements on a Web page through a variety of techniques.
• Selectively disable Internet Explorer settings.
• View HTML object class names, ID’s, and details such as link paths, tab index values, and access keys.
• Outline tables, table cells, images, or selected tags.
• Validate HTML, CSS, WAI, and RSS web feed links.
• Display image dimensions, file sizes, path information, and alternate (ALT) text.
• Immediately resize the browser window to a new resolution.
• Selectively clear the browser cache and saved cookies. Choose from all objects or those associated with a given domain.
• Display a fully featured design ruler to help accurately align and measure objects on your pages.
• Find the style rules used to set specific style values on an element.
• View the formatted and syntax colored source of HTML and CSS.

IE Developer Tools

http://msdn.microsoft.com/en-gb/library/dd565628%28VS.85%29.aspx

Every installation of Internet Explorer 8 comes with the Developer Tools. This tool enables Web site developers to quickly debug Microsoft JScript, investigate a behavior specific to Internet Explorer, or iterates rapidly to prototype a new design or tries solutions to a problem on-the-fly.

Getting started with the tools is simple: press F12 or click Developer Tools from the Tools menu.

Opera Dragonfly

http://www.opera.com/dragonfly/

Opera Dragonfly allows you to develop more quickly and easily by providing tools to debug your JavaScript and to inspect the DOM, CSS, network traffic and data stores. Developing for mobile has never been easier with Opera Dragonfly’s built-in remote debugging. Opera Dragonfly can be activated from the Developer Tools menu or by right-clicking and selecting Inspect Element. Opera Dragonfly’s source is available to view,  it is released on a Apache 2.0 license.

• Debug JavaScript
• Inspect the DOM
• Redefine your style
• Monitor the Network
• Dig through your storage
• Spot your errors
• Design Utilities
• The Opera debug menu
• Debug your phone or TV

Opera Dragonfly allows you to debug web pages from your desktop, that are being displayed on your mobile phone remotely (with opera mobile), to see how go to this article http://my.opera.com/ODIN/blog/opera-mobile-10-and-its-remote-debugging-party-trick.

Standalone tools

These tools go beyond of the browser tools and give you insights more professionals about what is happening in your web apps.

Dynatrace AJAX Edition

http://ajax.dynatrace.com/ajax/en/Default.aspx

dynaTrace AJAX Edition is the most powerful tool for optimizing your Web 2.0 applications. With so much code executing in the browser, it’s getting more and more difficult to keep your apps light and responsive. AJAX Edition v2.0 is a community-driven release that goes beyond debugging and diagnostics.

• Analyzes your code and tells you were your hotspots are
• Recommends proven solutions to common Web 2.0 problems
• Compares your site’s performance to your competitors’
• Provides deep insight across AJAX, Javascript, rendering, caching, & more
• Supports Internet Explorer 6, 7, and 8

Showslow

http://www.showslow.com/

Show Slow is an open source tool that helps monitor various website performance metrics over time. It captures the results of YSlow, Page Speed and dynaTrace AJAX Edition rankings and graphs them, to help you understand how various changes to your site affect its performance.

HTTP Watch

http://www.httpwatch.com/

HttpWatch is an integrated HTTP sniffer for IE and Firefox that provides new insights into how your website loads and performs, has a comprehensive  automation interface that can be used by most programming languages (e.g. C#, Javascript & Ruby). The interface can be used to control the HttpWatch plug-in for IE or Firefox and to access data in HttpWatch log files.

• HttpWatch captures a wide range of HTTP related data including:
  • Headers and Cookies
  • URLs and method (e.g. GET, POST, etc)
  • Parameters sent in a query strings and POST requests
  • HTTP status codes and errors
  • Redirections
  • The network size of the HTTP response including headers
  • Chunked encoding

• Integrates With Internet Explorer and Mozilla Firefox
• Compact & Comprehensive Log Files
• Includes a Standalone Log File Viewer
• Summary of Recorded Traffic
  • Performance
  • Page Events
  • Timings
  • Status Codes
  • Errors
  • Warnings

• Grouping Of Requests By Page
• Real-Time Page Level Time Charts
• Request Level Time Charts
• Page Level Events
  • DOM Load
  • Page Load
  • Render Start
  • HTTP Load

• Detects Potential Problems

Fiddler

http://www.fiddler2.com/fiddler2/

Fiddler is a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP(S) traffic, set breakpoints, and «fiddle» with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language. Fiddler is freeware and can debug traffic from virtually any application, including Internet Explorer, Mozilla Firefox, Opera, and thousands more.

Monitoring iPhone web traffic (with Fiddler)
You can ‘sniff’ the web traffic coming from an iPhone, to see how go to this link: http://conceptdev.blogspot.com/2009/01/monitoring-iphone-web-traffic-with.html

Mite

http://mite.keynote.com/

Mite is a powerful, desktop-based tool for testing and validating mobile Web content. Mite will reduce your time to market and help you deliver a better end-user experience. With a customizable library of over 1,800 devices and 11,000 device profiles, Mite gives you unequalled access to screen compatibility and application support information.

Keynote Mite lives on your desktop giving you instantaneous feedback. Navigate a site and validate that content appears as you’ve intended while checking that links are functioning properly. Mite also provides a download summary, a performance summary, re-directs, headers, cookies and detailed waterfall graph for further investigation.

Charles Debugger

http://www.charlesproxy.com/

Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).

Charles makes debugging quick, reliable and advanced; saving you time and frustration

• Records all traffic between your browser and the Internet
• Reveals the contents of all requests, responses, cookies and headers
• Supports SSL and HTTPS
• Saves valuable time
• Simulates slower internet connections
• Download statistics
• Configurable
• Quickly find and eliminate bugs

With Charles Debugger You can debug iphone web apps, to know how, see: http://blog.mediarain.com/2009/08/iphone-http-connection-debugging/

JSDoc toolkit

http://code.google.com/p/jsdoc-toolkit

JsDoc Toolkit is an application, written in JavaScript, for automatically generating template-formatted, multi-page HTML (or XML, JSON, or any other text-based) documentation from commented JavaScript source code.

YUIDoc

http://yuilibrary.com/projects/yuidoc

YUI Doc is a tool written in Python that generates beautiful, organized, searchable API documentation for your JavaScript code. You will typically use YUI Doc as part of your build process. YUI Doc is comment-driven and is compatible with a variety of coding styles. You do not need to be using YUI Library JavaScript in order to use YUI Doc.

MS Visual Round Trip Analyzer

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=119F3477-DCED-41E3-A0E7-D8B5CAE893A3&displaylang=en

The Visual Round Trip Analyzer tool helps web developers and testers visualize the download of their page, identify best practices and changes that improve web performance. The network Round-Trip between the client and server(s) is the single biggest impact to web page performance – much greater than server response time. VRTA examines the communications protocol, identifying the causes of excessive round-trips, and recommending solutions. Performance engineers, testers, developers, operations personnel should use VRTA to conduct their web performance analysis.

HTTP Scoop

http://www.tuffcode.com/index.html

HTTP Scoop passively listens for HTTP requests from any browser (or other application for that matter) running on your Mac.

There’s no special configuration needed, no cumbersome proxies required. You just hit the Scoop button and off you go.

• Capture HTTP conversations
• View headers, parameters & more
• View & save responses
• Any browser/client or server
• No proxy or browser plug-in
• Great for AJAX and Web Services

Web tools

These are tools that you use directly on the code or an URL to test your web sites /apps.

Boomerang

http://yahoo.github.com/boomerang/doc/

Boomerang is a piece of javascript that you add to your web pages, where it measures the performance of your website from your end user’s point of view. It has the ability to send this data back to your server for further analysis. With boomerang, you find out exactly how fast your users think your site is. All you have to do is stick it into the bottom of your web pages and call the init() method.

Boomerang is opensource and released under the BSD license.

YUI Profiler

http://developer.yahoo.com/yui/profiler/

The YUI Profiler is a simple, non-visual code profiler for JavaScript. Unlike most code profilers, this one allows you to specify exactly what parts of your application to profile. You can also programmatically retrieve profiling information as the application is running, allowing you to create performance tests YUI Test or other unit testing frameworks.

Perfectomobile

http://www.perfectomobile.com

Test Mobile Applications on Real Devices.

The Perfecto Mobile Handset Cloud system enables you to access and control real mobile devices via the web. Using the system you can quickly and easily operate the phone keys, touch-screen, or QWERTY keyboard to control the device, install applications on the device and verify that your application or service works properly and displays correctly on the phone’s screen.

The Perfecto Mobile system is a hardware and software solution. The mobile handset is mounted on a cradle that holds it in a specific location. A video camera, located in front of the handset’s screen, captures the real user experience as it is displayed on the handset’s screen.

• Controlling a remote device
• Typing Text.
• Installing an application on the handset
• Keep a record of your actions and collaborate
• Screen Shots.
• Video Clips.
• On-Line.
• Testing interruptions.
• Sending SMS.
• Web-based UI.

The members of the Opera Developer Network get 7 hours of remote access, free of charge.
http://www.perfectomobile.com/portal/cms/opera.xhtml?key=OP631R89YL2

Web Page Test

http://www.webpagetest.org/

WebPagetest is a tool that was orginially developed by AOL for use internally and was open-sourced in 2008. The online version at http://www.webpagetest.org is an industry collaboration with various companies providing the testing infrastructure for testing your site from across the globe.

JSLint

http://www.jslint.com/

JSLint is a JavaScript program that looks for problems in JavaScript programs. It is a code quality tool.

Minification is the process of eliminating white space, comments, and other nonessential parts of the javascript code to decrease the size of the JS files that need to be transfered from the server to the browser.

YUI Compressor

http://yuilibrary.com/projects/yuicompressor/

YUI Compressor is an open source tool that supports the compression of both JavaScript and CSS files. The JavaScript compression removes comments and white-spaces as well as obfuscates local variables using the smallest possible variable name. CSS compression is done using a regular-expression-based CSS minifier.

Google Closure Compiler

http://code.google.com/intl/es-AR/closure/compiler/

The Closure Compiler reduces the size of your JavaScript files and makes them more efficient, helping your application to load faster and reducing your bandwidth needs.

The Closure Compiler provides warnings for illegal JavaScript and warnings for potentially dangerous operations, helping you to produce JavaScript that is less buggy and and easier to maintain.

The Closure Compiler is a tool for making JavaScript download and run faster. It is a true compiler for JavaScript. Instead of compiling from a source language to machine code, it compiles from JavaScript to better JavaScript. It parses your JavaScript, analyzes it, removes dead code and rewrites and minimizes what’s left. It also checks syntax, variable references, and types, and warns about common JavaScript pitfalls.

To help you work with your transformed code, you can also install the Closure Inspector, a tool that makes it easy to use the Firebug JavaScript debugger with the Compiler’s output.

The Closure Compiler has also been integrated with Page Speed, which makes it easier to evaluate the performance gains you can get by using the compiler.

Conclusion

Web performance monitoring and analysis tools can provide a lot of knowledge about how your end-users uses the website or web app from different perspectives, so it is very important to know the tools that we have to measure different parts of the applications.