Page load times can be significantly improved by asking visitors to save and reuse the files included in your website.

• Reduces page load times for repeat visitors
• Particularly effective on websites where users regularly re-visit the same areas of the website
• Benefit-cost ratio: high
• Access needed

All static resources should have either a Last-Modified or ETag header. This will allow browsers to take advantage of the full benefits of caching.

Removing « broken links », or requests that result in 404/410 errors, avoids wasteful requests.

Redirections on landing pages add delays to the page load and while the redirections are occurring, nothing is shown to the client. In many cases, redirections can be eliminated without changing the function of a page.

Minimizing HTTP redirects from one URL to another cuts out additional RTTs and wait time for users.

In order to load a page, the browser must parse the contents of all <script> tags, which adds additional time to the page load. By minimizing the amount of JavaScript needed to render the page, and deferring parsing of unneeded JavaScript until it needs to be executed, you can reduce the initial load time of your page.

Reduce the size of files sent from your server to increase the speed to which they are transferred to the browser.

• Reduce sizes of pages by up to 70%
• Increase page speed
• Cost-benefit ratio: high
• Access needed to the .htaccess files or server administration files

Enabling HTTP Keep-Alive or HTTP persistent connections allow the same TCP connection to send and receive multiple HTTP requests, thus reducing the latency for subsequent requests.

Inlining small external CSS files can save the overhead of fetching these small files. A good alternative to inline CSS is to combine the external CSS files.

Inlining small external JavaScript files can save the overhead of fetching these small files. A good alternative to inline JavaScript is to combine the external JavaScript files.

Using CSS @import in an external stylesheet can add additional delays during the loading of a web page.

Moving inline style blocks and <link> elements from the document body to the document head improves rendering performance.

Compacting CSS code can save many bytes of data and speed up downloading, parsing, and execution time.

Compacting JavaScript code can save many bytes of data and speed up downloading, parsing, and execution time.

Keeping cookies and request headers as small as possible ensures that an HTTP request can fit into a single packet.

Serving appropriately-sized images can save many bytes of data and improve the performance of your webpage, especially on low-powered (eg. mobile) devices.

Reduce the load times of pages by loading appropriately sized images.

• Reduce file sizes based on where images will be displayed
• Resize image files themeselves instead of via CSS
• Save files in appropriate format depending on usage
• Cost benefit ratio: high value
• Access needed

It’s important to serve a resource from a unique URL, to eliminate duplicate download bytes and additional RTTs.

Combining images into as few files as possible using CSS sprites reduces the number of round-trips and delays in downloading other resources, reduces request overhead, and can reduce the total number of bytes downloaded by a web page.