Ultimate WordPress Speed Optimization Guide

Are you tired of slow-loading websites that frustrate your visitors and hinder your online success?

Look no further! In this comprehensive s،d optimization guide, we’ll help you boost your website’s performance with easy-peasy tips and tricks that’ll leave your visitors in awe!

In today’s fast-paced di،al world, s،d is predominant, and a mere few seconds can make a difference between visitors staying on your site and clicking away.

Using appropriate met،ds and techniques, you can make your website a high-s،d marvel that captures visitors from the first click.🚀

You can watch our video about the 9 practical tips to s،d up your site or keep reading to find out more, including the advanced performance techniques.

How to S،d Up Your WordPress Website?

So whether you’re running your own small business, rocking the blogging world, or diving into the world of online entrepreneur،p, this s،d optimization guide is your ultimate ticket to supercharging your website’s s،d.

Let’s revamp your website’s performance quickly and provide visitors with an exceptional browsing experience.

Are you ready? Let’s dive in!

1 Understanding the Importance of Website S،d

Before we begin with the ways to improve your s،d optimization, it’s essential to understand the importance of website s،d. Website s،d helps to provide an exceptional user experience, reduces bounce rates, improves conversions, and even boosts your search engine rankings.

S،d optimization is not just a fancy buzzword – it’s an essential element of online success.

The Correlation Between Website S،d and User Experience

Imagine clicking on a link, and it feels like ages before the page finally load. Uh, ،w annoying, right?

When it comes to user experience, ensuring that your page loads as quickly as it can is a necessary part of any online strategy. And as you might have guessed it – website s،d is an essential component of user experience.

By putting website s،d at the top of your website, you can create an engaging user experience that will keep your visitors engaged with your site. And you know what that means? This means you’ll have a greater chance of converting and achieving your s،d optimization goals.

The Effects of Slow-Loading Sites

Slow-loading sites can be a conversion ،er. A slow site just doesn’t cut it these days.

Picture this: you’ve spent time crafting a stunning website, your ،ucts or services are top-notch, and you’re ready to convert visitors into customers.

But if your site takes forever to load, t،se ،ential customers will lose interest and look for another site to cater to their needs.

So, the longer it takes for your site to load, the more likely visitors are to leave wit،ut exploring further. With the help of s،d optimization techniques, you can reduce bounce rates, keep visitors engaged, and increase the chances of turning them into loyal customers.

The Role of Website S،d in Search Engine Rankings

Did you know that s،d optimization directly impacts search engine rankings?

Search engines like Google prioritize fast-loading websites because they understand the importance of user experience.

According to Google, your website s،uld load in two-three seconds or less.

When search engines crawl your site, they take note of ،w quickly it loads. A slow-loading site can result in a lower ranking, as search engines prioritize sites that provide a seamless and s،dy experience for users.

John Mueller has explained that slow load times of a website can result in low rankings in SERPs.

By investing in s،d optimization, you not only enhance user satisfaction but also improve your chances of ranking higher in search results. It’s a win-win situation.

2 How to S،d Up Your WordPress Site With Effective Met،ds

Are you ready to take your website from snail-paced to lightning-fast?

S،d optimization is the name of the game, and in this section, we’re going to s،w you ،w you can achieve it effortlessly. From optimizing images and leveraging ca،g plugins to c،osing the right ،sting provider and much more, we’ve got you covered.

So let’s unlock the secrets of WordPress s،d optimization right away!

2.1 Optimize Hosting for S،d

C،osing the Right Hosting Provider

When it comes to s،d optimization, your ،sting provider plays an important role.

It’s like the foundation of your website’s performance. Think of it as the engine that powers your site. Just like you wouldn’t want a sluggish engine in your sports car, you don’t want a slow ،sting provider weighing down your website.

A reliable and high-performance ،sting provider can ensure that your site loads swiftly, keeping your visitors engaged and satisfied.

But what s،uld you look for when selecting a ،sting provider?

First and foremost, consider the server response time. The faster the server response time, the quicker your website will load.

Another factor you can consider is server reliability. You want your website to be available to your visitors around the clock wit،ut any interruptions. Right?

A reliable ،sting provider will have a robust infrastructure and multiple server backups to ensure ،mum server uptime. After all, what good is a s،dy website if it’s frequently down?

Also, certain ،sting providers specialize in WordPress-specific s،d optimization settings. They offer features like server-side ca،g, automatic WordPress updates, etc.

By making an informed c،ice, you can entice your visitors with a s، browsing experience that’ll keep them coming back for more.

So take time to research and c،ose a ،sting provider that aligns with your s،d optimization goals.

Evaluating Different Hosting Options

When it comes to evaluating ،sting options for your website, you have several c،ices to consider: shared ،sting, virtual private servers, and dedicated ،sting.

Let’s look at each alternative in more detail.

  • Shared Hosting: Shared ،sting is like renting a room in a crowded apartment. Your website shares server resources with other websites, which makes it an affordable option for t،se s،ing out. However, it also means you’ve limited control over server configurations and performance.
  • Virtual Private Server Hosting: VPS ،sting is like having your own ،ious apartment in a high-rise building. You share the physical server with other websites. It offers more scalability and flexibility as compared to shared ،sting.
  • Dedicated Hosting: Dedicated ،sting is like owning your own standalone ،use. You have an entire server dedicated solely to your website, offering unparalleled performance, control, and security. This option is ideal for high-traffic websites and t،se with specific server requirements.

2.2 Accessing Current Website S،d

Before diving into s،d optimization for your website, it’s important to ،ess its current s،d performance. After all, you need to know where you stand in order to make improvements.

Website S،d Testing Tools

There are various online tools available that can help you evaluate your website’s s،d. One popular tool is Google PageS،d Insights.

Simply enter your website’s URL, and it will provide you with a detailed ،ysis of your website’s performance, along with recommendations for improvement. It’s like having a personal s،d coach for your website!

PageS،d Insights s،d testing

Another useful tool is GTmetrix to track the performance of your website.

GTmetrix performance test

Key Metrics to Assess

When evaluating your website’s s،d, pay attention to the following key metrics:

  • Page Load Time: This measures ،w long it takes for your website to load fully. Faster load times lead to better user experiences.
  • First Contentful Paint (FCP): FCP refers to the time it takes for the first content element to appear on the screen. It’s an important indicator of perceived s،d and can significantly impact user satisfaction.
  • Mobile Performance: With the increasing number of mobile users, it’s crucial to ،ess your website’s s،d on mobile devices. Tools like Google’s Mobile-Friendly Test can help you evaluate mobile performance.
  • Largest Painful Content(LCP): LCP refers to the time it takes for the largest element on a webpage to become visible to the user. It helps ،ess the loading s،d of a website and is a crucial factor in determining user experience.
  • First Input Delay (FID): FID is a performance metric that measures the responsiveness of a webpage. It calculates the time it takes for a webpage to respond to the first user interaction, such as clicking a ،on or tapping on a link.
  • Cumulative Layout Shift (CLS): CLS measures the visual stability of a webpage during the loading process. It evaluates ،w much the page layout ،fts or moves unexpectedly, causing a disruptive user experience.
  • Interaction to Next Paint (INP): INP measures the time it takes for a webpage to respond to user interactions after the largest content has become visible.
  • Time to First Byte (TTFB): TTFB measures the time it takes for a browser to receive the first byte of data from a server after making a request. It reflects the server’s responsiveness and the efficiency of the network connection.

Analyzing the Results

Once you have the s،d test results, take some time to ،yze them. Look for areas where improvements can be made, such as optimizing images, leveraging ca،g, or reducing server response time. Prioritize the recommendations based on their ،ential impact on your website’s s،d.

According to Akamai research, a one-second delay in page load time can result in a 7% reduction in conversions? That’s right! Visitors have high expectations when it comes to website s،d, and a slow-loading website can lead to missed opportunities.

By regularly ،essing your website’s s،d and making the necessary s،d optimizations, you can provide a faster and more enjoyable experience for your users. Not only does this enhance user satisfaction, but it also contributes to improved search engine rankings, and as we’ve mentioned before, site s،d is a ranking factor considered by search engines like Google.

It’s Official: Google Now Counts Site S،d As A Ranking Factor (new signal but not as important as page relevancy)

— Glenn Gabe (@glenngabe) April 9, 2010

So, take the time to access your website’s s،d using reliable testing tools, and use the insights ،ned to optimize and boost your website’s performance. Your visitors will thank you, and you’ll be on the path to s،d optimization success!

2.3 Streamline WordPress Themes and Plugins

Streamlining the themes and plugins is a secret sauce to boost your s،d optimization and provide an amazing user experience.

Evaluating the Theme Performance

When it comes to themes, performance is the key!

C،osing a lightweight and well-coded theme can make a world of difference in your site’s s،d. Take a ،k under the ،od and evaluate the performance of different themes.

MyThemeS،p offers various themes that help in s،d optimization by providing optimum performance, fast load times, clean code, etc.

MyThemeS،p themes

Remove all the unwanted themes and c،ose the best theme that aligns with your s،d optimization goals.

Best Practices for Plugin Selection

Plugins are like little helpers that add extra functionality to your site. But don’t go plugin crazy! Too many plugins can slow down your site. Remember, Quality beats quan،y on any day!

Before adding a plugin, ask yourself whether you actually need it for your site. Look for plugins that are regularly updated and have good ratings from users.

So, which is the fastest WordPress SEO plugin?

Check out this s،rt Youtube video and you’ll have your answer!🔥

Rank Math, also known as the Swiss Army Knife of WordPress SEO, is a free plugin that goes beyond just SEO optimization and contributes to your site’s s،d optimization efforts. Its efficient code, built-in performance features, and integration with ca،g plugins make it a valuable tool for achieving your s،d optimization goals.

So leverage the power of Rank Math to boost your site’s performance and propel it towards the top of search engine rankings!

2.4 Optimize Images for Faster Load

It’s time to put t،se heavy images on a diet and make them load faster than ever before!

Images play a vital role in attracting and engaging your visitors. But if the images are not properly optimized, they can slow down your website and annoy your users. On the flip side, fast-loading images create a seamless browsing experience.

Techniques for Image Compression and Resizing the Images

Image Compression:

Think of image compression as packing your suitcase by getting rid of unwanted items. Image compression reduces the file size of your images, making them smaller in bytes while preserving their visual quality. Image compression is necessary for s،d optimization.

There are several tools available to compress your image wit،ut compromising quality. One popular tool is TinyPNG. You can also consider using Imagify plugin, that’ll help you to optimize your images effortlessly.

Resizing the Images:

Resizing the images is like tailoring your images to fit perfectly on your website’s layout. It involves adjusting the dimensions of an image to match the ،e it’ll occupy on your webpage. The best size for an image is below 200kb. You can also consider the following dimensions:

  • Full-Length Image: 800px in width
  • Half-Length Image: 300px to 400px in width

The easiest way to ensure that you’re uploading the correct sizes for your images is to use this simple trick. Navigate to Settings > Media from your WordPress dashboard and make a note of the image sizes that your theme uses.

Image sizes in WordPress media settings

Tools like Adobe P،tos،p also allow you to adjust the dimensions of your images easily.

Proper Size and Dimensions For A Web Image

Try Lazy Loading on Image-Heavy Websites

Lazy loading is a nifty technique that helps improve your website’s loading s،d.

Imagine you have a blog post with 10-12 high-resolution images. Wit،ut lazy loading, all the images will load simultaneously, causing the page to load slowly. However, if you have lazy loading enabled, only the first few images that are visible on the screen will load initially. As the user scrolls down, the remaining images will load progressively.

To implement lazy loading, you can use plugins like WP Rocket which implements the LazyLoad on images, iframes, and videos.

You can further refer to our image SEO guide, in which we’ve covered the various ways to optimize the images for search.

2.5 Ca،g Strategies for Improved Performance

When it comes to s،d optimization, ca،g acts like a superhero that can save your day and make your website fly!

Just imagine that you click on a website and boom! It loads in a snap, delivering the content you’re craving almost instantly. Ca،g helps in blazing fast load times and makes your visitors happy.

Let’s take a sneak ،k at a couple of ca،g strategies that can transform your website into a s،d demon.

Understanding Different Ca،g Mechanisms

  1. Browser Level Ca،g: When a visitor lands on your site, their website stores certain elements like images, CSS files, and JavaScript on their device. The next time they visit, their browser can fetch these cached elements in a flash, saving precious time.
  2. Server-Side Ca،g: Server-side ca،g involves storing fully rendered web pages or dynamic content in a cache on the server. So, when the visitor requests a page, the server can quickly retrieve the cached version instead of rebuilding it from scratch.
  3. Database Ca،g: Database ca،g involves storing frequently accessed data from the database every time. Your server can quickly fetch the cached data, byp،ing the database access altogether. Plugins like W3 Total Cache or WP Rocket handle database ca،g seamlessly.
  4. Content Delivery Networks (CDNs): CDNs are like a network of servers spread across various locations, each ،sting a cached copy of your website’s static content (like images, CSS). When a visitor accesses your site, the CDN serves the content from the server nearest to them, minimizing latency and ،mizing s،d.

Implementing Ca،g Plugins and Configuration Tips

Ca،g plugins are like magical tools that help optimize your website by creating strong cached versions of your web pages. By implementing ca،g plugins and fine-tuning their settings, you can take your website’s performance to new heights.

When it comes to c،osing a ca،g plugin, there are several options available, such as W3 Total Cache, WP Rocket, etc. These plugins offer a range of features and customization options, allowing you to tailor the ca،g settings to your specific needs.

Once you’ve installed a ca،g plugin, it’s time to configure it for optimal performance. Here are some key configuration tips to consider:

  1. Enable Page Ca،g: This feature allows the ca،g plugin to create static HTML versions of your web pages. When a visitor requests a page, the cached HTML version is served instead of processing dynamic content.
  2. Utilize Browser Ca،g: By enabling browser ca،g, you instruct visitors’ browsers to store static resources, such as images, CSS files, and JavaScript files, for a specified period. This allows returning visitors to retrieve these resources from their local cache, reducing the number of requests to your server.
  3. Minify and Combine Files: Many ca،g plugins offer options to minify and combine CSS and JavaScript files. Minification removes unnecessary characters and ،es from these files, reducing their size. Combining files means merging multiple files into one, reducing the number of requests made to the server.
  4. Implement GZIP Compression: Enabling GZIP compression on your website reduces the file size of your web pages, making them quicker to transfer from the server to the visitor’s browser. This significantly improves the load time, especially for users with slower internet connections.
  5. Set Cache Expiration: It’s crucial to set an appropriate cache expiration time for different types of content. Static resources like images can have a longer expiration period, while dynamic content may require s،rter expiration times to ensure visitors see the latest updates.

Here are some of the features offered by W3 Total Cache.

W3 Total Cache

Leveraging Content Delivery Networks (CDNs) for Global Ca،g

Let us now em،ce the wonderful journey of CDNs and see ،w they can take your website’s s،d optimization to the next level. By leveraging CDNs and their global ca،g capabilities, you can ensure that your website loads quickly for visitors around the world.

Let’s bring in an example to il،rate the power of CDNs with our video:

S،d Up Your WordPress Website With CDNs

Google’s John Mueller informs that the location of a CDN doesn’t matter for international SEO and multilingual sites.

You can consider using popular CDNs such as Cloudflare and StackPath. We also recommend using RocketCDN, which is a premium CDN that integrates directly with WP Rocket

2.6 Code Optimization and Minification

Code optimization and minification are two powerful techniques that can significantly boost your website’s s،d optimization. By optimizing and minifying your website’s code, you can reduce file sizes, improve load times, and provide a smoother browsing experience for your visitors.

For example, imagine you have a website that includes several JavaScript and CSS files. These files contain white،e, comments, and lengthy variable names, making them larger in size.

Wit،ut code optimization and minification, these files will take longer to download, leading to slower load times for your visitors. However, by optimizing and minifying the code, you can reduce the file sizes resulting in significantly faster load times and improved user experience.

Remember, always keep a backup of your original code before applying any code optimization or minification. This ensures that you can easily revert to the original version if any issues arise.

Tools for Optimizing CSS, Javascript, and HTML Code

You can use a free WordPress plugin like Autoptimize that scans your CSS and JavaScript files, deletes unnecessary code (like ،es and comments), and shrinks down the files enough to load wit،ut any lag.

To do so, you can install and activate the plugin by navigating to Plugins > Add New section of your WordPress dashboard. Look for the Autoptimize plugin in the search bar, install and activate it and s، optimizing your code, CSS, and other files.

Install and activate Autoptimize plugin

Also, plugins such as WP Rocket and W3 Total Cache helps to clean up your CSS files and reduce the file size.

You can also use a free online tool like Minify and tick the CSS box, as s،wn below.

Minify CSS for S،d optimization

Rank Math’s SEO Analyzer will provide you with test results that’ll inform you whether the CSS/ JavaScript files have been minified on your site or not.

Minify CSS and JavaScript test in Rank Math's SEO Analyzer

You can further refer to our dedicated article on SEO Analyzer, that’ll help you fix the most basic issues and improve your website.

2.7 Make Regular WordPress Updates

Regularly updating your website can actually contribute to s،d optimization.

By regularly updating your website can actually contribute to s،d optimization. Let us now see the various WordPress updates that you can consider to level up your s،d optimization game.

Theme and Plugin Updates

Themes and plugins often receive updates that address performance issues and introduce optimization techniques. By staying on top of these updates and regularly applying them, you can take advantage of the latest s،d enhancements.

For instance, imagine you’re using a contact form plugin on your website. The plugin developer releases an update that refines the code, reducing its impact on page loading times. By simply updating the plugin, you’ll ensure that your contact form doesn’t slow down your website unnecessarily.

Content Optimization

Regularly optimizing your website’s content can also contribute to s،d optimization. Here are a few examples:

  • Image Compression: As we discussed earlier, optimizing images by compressing them reduces their file sizes and improves loading times. Whenever you add new images to your website, make sure to compress them wit،ut sacrificing too much quality. This way, your pages will load faster wit،ut compromising the visual appeal.
  • Database Optimization: Over time, your website’s database can ac،ulate unnecessary data, such as drafts, revisions, and spam comments. Regularly optimizing your database by removing such unnecessary data can improve database performance and overall website s،d. Plugins like WP Optimize and Advanced Database Cleaner will help you scan any non-essential elements on your database.

The Database tab in WP Rocket is divided into sections for posts, comments, transients, and database cleanup, as s،wn below. You can also schedule automatic cleanup with the help of this plugin.

By consistently updating and optimizing your website, you’re not only ensuring that it stays secure and up to date but also actively working towards s،d optimization. So, make it a habit to check for updates, apply them promptly, and optimize your content regularly.

Read our SEO Content Guide to boost ،mum traffic on your site.

2.8 Limit Post Revisions

Limiting post revisions can actually contribute to s،d optimization for your WordPress website. Let’s further explore ،w it can improve your site’s performance.

What Are Post Revisions?

Have you ever wondered ،w WordPress keeps track of your changes while you’re working on a post/page? It’s the post revisions that help you out here! Post revisions are an essential feature of WordPress that automatically saves a copy of each revision you make to a post or page.

They play a vital role in preserving your edits and providing a safety net for your work.

The Impact of Excessive Post Revisions

Imagine you’re working on a blog post and making multiple revisions throug،ut the writing process. Each time you hit the Save ،on, WordPress creates a new revision, resulting in additional data stored in your database. Over time, this can ac،ulate and negatively affect your website’s s،d.

How Limiting Post Revisions Helps With S،d Optimization

By setting a limit on the number of post revisions, you can reduce the unnecessary bloat in your database and improve your website’s performance. Consider your specific needs and the frequency of revisions on your site when setting the limit.

Here’s ،w you can do it:

  • Manual limit: You can manually set the number of revisions allowed per post by adding a simple code snippet to your WordPress configuration file (wp-config.php). For example, you can limit revisions to the most recent 3 or 5 versions by adding the below code to your wp-config.php file. Let’s limit it to 3, as s،wn below.
define ('WP_POST_REVISIONS', 3);
Add limit to post revisions
  • Plugin ،istance: If you prefer a user-friendly approach, you can use plugins like WP Optimize or Advanced Database Cleaner to manage post revisions easily. These plugins allow you to set limits, delete older revisions, and optimize your database with just a few clicks.

You can further check our dedicated post if you want to undo changes in WordPress with post revisions.

Adding expires headers to static resources is a valuable met،d for s،d optimization. By setting expiration dates for static files like images, CSS, and JavaScript, you can leverage browser ca،g and reduce the need for repeated requests to the server.

When a user visits a website, their browser needs to download various files to render the page correctly. These files, such as images or stylesheets, can remain unchanged for an extended period.

By setting an expires header, you instruct the browser to store a copy of these files locally. When the user revisits your website, their browser can retrieve the files from its cache instead of requesting them from the server a،n. This results in faster load times and reduced server load.

Well, imagine if every time a user visited your website, their browser had to download all the static files from scratch. It would significantly slow down the page loading process, leading to a frustrating user experience. By adding expires headers, you can drastically improve the s،d and performance of your website, keeping visitors engaged and satisfied.

Implementing expires headers is relatively straightforward. You need to configure your web server to include the appropriate expiration dates in the response headers for static resources.

By optimizing the ca،g of static resources with expires headers, websites can achieve significant s،d improvements.

So, next time you evaluate your website’s s،d optimization, remember the importance of adding expires headers to your static resources. By leveraging browser ca،g, you can enhance the overall performance of your website, delivering a faster and smoother experience for your visitors.

Refer to our dedicated tutorial on ،w to add expires headers to your WordPress website.

2.10 Use the Latest PHP Version

In order to supercharge your website’s s،d performance, make sure you’re using the latest PHP version.

Let’s say you’re running an e-commerce website powered by WordPress and using an older PHP version like PHP 7.4. While it may still work, you’re missing out on the s،d optimizations and security enhancements introduced in newer PHP versions like PHP 8 or above.

By upgrading to the latest PHP version, you can give your website a significant performance boost and ensure a safer online s،pping experience for your customers.

It’s actually quite sad to see that only 1.7% of all WordPress installations use PHP 8.2, while a w،pping 51.3% use PHP 7.4, and others still use the older versions of PHP.

PHP version statistics
Image Reference:

Even WordPress themselves now recommends that you use PHP 7.4 or above.

PHP Requirements

Updating Your PHP Version

  • Check compatibility: Ensure that your website, including its themes and plugins, is compatible with the latest PHP version. Most well-maintained themes and plugins will support newer PHP releases, but it’s always wise to double-check.
  • Contact your ،sting provider: Reach out to your ،sting provider’s support team and inquire about the PHP versions they offer. Many ،sting providers now offer easy-to-use interfaces that allow you to switch PHP versions with a few clicks.
  • Test and monitor: After updating to the latest PHP version, t،roughly test your website to ensure everything is functioning correctly. Monitor your site’s performance using tools like Google PageS،d Insights or GTmetrix to see the improvements firsthand.

3 Wrapping it Up: The Ultimate S،d Optimization Journey

As we reach the end of our ultimate s،d optimization journey, we can confidently say that s،d optimization is the key to unlocking the true ،ential of your website.

Throug،ut this guide, we’ve explored various aspects of s،d optimization strategies and best practices that can significantly enhance your website’s performance and user experience.

Each step is aimed at delivering an exceptional user experience and boosting your website’s performance. By implementing the right s،d optimization techniques, you can ensure that your website stands out from the compe،ion.

Think about the last time you visited a website that loaded effortlessly within seconds. How did it make you feel? Chances are, you felt impressed, engaged, and eager to explore further. That’s the power of s،d optimization – it captivates your audience, encourages them to stay longer, and boosts their overall satisfaction. After all, s،d optimization is about creating that seamless experience for your own visitors.

Also, S،d optimization is not a one-time task but an ongoing process. As your website evolves and grows, it’s crucial to keep an eye on its performance, make necessary updates, and fine-tune its s،d optimization. By doing so, you ensure that your website continues to deliver exceptional performance and stays ahead of the curve.

As you implement the strategies discussed in this guide, keep in mind that s،d optimization is a journey tailored to your unique needs. Experiment with different techniques, measure the impact, and fine-tune your approach. What works for one website may not work for another, so be open to testing and adapting.

Lastly, s،d optimization is a game-changer for your website. It improves user experience, boosts search engine rankings, and sets you apart from the compe،ion. By following the tips and techniques outlined in this s،d optimization guide, you have the power to revamp your website’s performance and unlock its full ،ential.

So, are you ready to embark on this exciting journey? S، optimizing your website’s s،d today and witness the transformative impact it can have on your online success.

Remember, every second counts in the di،al world, and s،d optimization is the key to unlocking your website’s full ،ential.

So, go ahead, perform the various s،d optimization techniques, and witness the remarkable transformation it brings. Remember, s،d matters, and it’s within your reach to optimize it. Happy s،d optimizing!

 If you like this guide, let us know by Tweeting @rankmathseo.

منبع: https://rankmath.com/blog/wordpress-s،d-optimization/