Website Performance Optimization: Overview
People don't like to wait, especially online. If a web page takes too long to load, visitors simply leave and often don't come back. 'Slow' is the biggest frustration on the web. Load time is directly related to the financial performance of the website.Studies show that users leave a site if it hasn't loaded in 4 seconds; keep your users happy and engaged by providing a fast performing website!
Amazon noticed a 1% drop in sales for every 0.1 second the site loaded slower. In an AB test, Google raised the number of search results per page from 10 to 30. Load time went up from 0.5 to 0.9 seconds average. The number of search results and ad revenues dropped 20%!
Google has announced that they are using page speed in their ranking algorithm, as their philosophy says: "Fast is better than slow."
Website Performance Optimization: Benefits
- Better user experience: Visitors return more often and do more on your website.
- More revenues: Ad impressions/clicks, sign ups and completed orders rise.
- Less costs: You need less server capacity and bandwidth.
- More traffic from Google search engine: Higher SERP positions, lower AdWords CPCs and more pages in the index.
- Better equipped to withstand big traffic spikes: Reduced risk of extreme slowness or down time.
Website Performance Optimization: 47 Rules
- Website Performance Optimization Rule 1: Make fewer HTTP requests
- Website Performance Optimization Rule 2: Add expires headers
- Website Performance Optimization Rule 3: Specify a Vary: Accept-Encoding header
- Website Performance Optimization Rule 4: Use a content delivery network (CDN)
- Website Performance Optimization Rule 5: Minify HTML
- Website Performance Optimization Rule 6: Minify CSS
- Website Performance Optimization Rule 7: Minify JavaScript
- Website Performance Optimization Rule 8: Minimize redirects
- Website Performance Optimization Rule 9: Minimize request size
- Website Performance Optimization Rule 10: Enable gzip compression
- Website Performance Optimization Rule 11: Enable Keep-Alive
- Website Performance Optimization Rule 12: Inline small CSS
- Website Performance Optimization Rule 13: Inline small JavaScript
- Website Performance Optimization Rule 14: Avoid AlphaImageLoader filter
- Website Performance Optimization Rule 15: Avoid URL redirects
- Website Performance Optimization Rule 16: Avoid empty src or href
- Website Performance Optimization Rule 17: Avoid bad requests
- Website Performance Optimization Rule 18: Avoid CSS @import
- Website Performance Optimization Rule 19: Avoid HTML 404 (Not Found) error
- Website Performance Optimization Rule 20: Avoid CSS expressions
- Website Performance Optimization Rule 21: Make AJAX cacheable
- Website Performance Optimization Rule 22: Make favicon small and cacheable
- Website Performance Optimization Rule 23: Make JavaScript and CSS external
- Website Performance Optimization Rule 24: Make landing page redirects cacheable
- Website Performance Optimization Rule 25: Put CSS in the document head
- Website Performance Optimization Rule 26: Put JavaScript at bottom
- Website Performance Optimization Rule 27: Remove unused CSS
- Website Performance Optimization Rule 28: Remove duplicate JavaScript
- Website Performance Optimization Rule 29: Remove query strings from static resources
- Website Performance Optimization Rule 30: Reduce the number of DOM elements
- Website Performance Optimization Rule 31: Reduce cookie size
- Website Performance Optimization Rule 32: Use cookie-free domains
- Website Performance Optimization Rule 33: Do not scale images in HTML
- Website Performance Optimization Rule 34: Use GET for AJAX requests
- Website Performance Optimization Rule 35: Use efficient CSS selectors
- Website Performance Optimization Rule 36: Configure entity tags (ETags)
- Website Performance Optimization Rule 37: Optimize images
- Website Performance Optimization Rule 38: Optimize the order of styles and scripts
- Website Performance Optimization Rule 39: Leverage browser caching
- Website Performance Optimization Rule 40: Defer parsing of JavaScript
- Website Performance Optimization Rule 41: Specify a cache validator
- Website Performance Optimization Rule 42: Specify a character set early
- Website Performance Optimization Rule 43: Specify image dimensions
- Website Performance Optimization Rule 44: Serve scaled images
- Website Performance Optimization Rule 45: Serve resources from a consistent URL
- Website Performance Optimization Rule 46: Combine images using CSS sprites
- Website Performance Optimization Rule 47: Prefer asynchronous resources
Website Performance Optimization: Resources
- Google Page Speed resources
- Google Page Speed articles and tutorials
- Yahoo! YSlow resources
Website Performance Optimization: Social Bookmarking and Sharing
- Share Tutorials and Courses for Website Performance Optimization on Google+
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