Jetpack Boost – Website Speed, Performance and Critical CSS

常見問題集

What does Jetpack Boost do to help speed up my WordPress site?

Jetpack Boost makes small changes to the way that data is sent from your WordPress site to your users’ browser, to enable the browser to display your site faster.

Jetpack Boost includes a growing number of separate features which can be turned on individually to improve your site’s performance. These include:

• Optimize CSS Loading: This feature determines the most important CSS that your site needs to display your site’s initial content as quickly as possible, and embeds it directly into your site header.
• Defer Non-Essential JavaScript: This feature forces all of the JavaScript which is not deemed essential to displaying your site to load after your site’s main content has been loaded.
• Lazy Image Loading: This feature delays loading images on your site until they are scrolled into view, allowing the browser to load the first content that the user will see first.
• Image CDN: This feature automatically resizes images to a more appropriate size for your visitors’ screens, converts them to modern image formats, and serves them from Jetpack’s worldwide network of servers.
• Concatenate JS: This feature reduces the size of your JavaScript resources, and automatically combines them into fewer files, allowing your site to load faster with fewer requests.
• Concatenate CSS: As with concatenating JavaScript, this feature shrinks your CSS files and allows them to load with fewer requests.

使用 Jetpack Boost 可以改進哪些網站項目的速度？

Website Performance is complicated and can be affected by a number of factors. As a result, it is difficult to accurately predict how much impact it will have on each site.

Generally, the lower your speed score is to begin with, the more Jetpack Boost may impact your performance. We have seen user reports of up to 25 Speed Score points improvement simply by installing and using Jetpack Boost.

However, as performance can be impacted by so many factors, it is also possible for Jetpack Boost to have a small negative performance impact in some rare cases.

We recommend that you install Jetpack Boost, and try it for yourself. It includes a tool for measuring your Speed Score, to check what impact it has on your site.

Jetpack Boost 是否也能延遲載入非必要 CSS？

Jetpack Boost automatically defers non-essential CSS if its “Optimize CSS Loading” feature is enabled.

The “Optimize CSS Loading” feature identifies the most important CSS rules your site needs to display your pages as quickly as possible (commonly called “Critical CSS”), and defers all other CSS rules from loading until your main content has loaded.

什麼是「網站使用體驗」？

「網站使用體驗」是 Google 讓使用者更容易了解網站使用者體驗的測量方式。要改善「網站使用體驗」，網站管理員也要改善網站的使用者體驗。

You can read more about Web Vitals on web.dev

Jetpack Boost 如何改善「網站使用體驗」？

Each Core Web Vital relates to an aspect of how quickly your site can load and appear on new visitors’ screens.

Jetpack Boost makes small changes to the way that data is sent from your WordPress site to your users’ browsers, to enable your content to load faster. As a result, it can improve your Core Web Vitals scores.

For example, our “Optimize CSS Loading” feature ensures the most important CSS rules are sent to users’ browsers as early as possible, improving both First Contentful Paint (FCP) and Cumulative Layout Shift (CLS) scores.

使用這個外掛需要搭配 Jetpack 使用嗎？

Jetpack Boost 是 Jetpack 品牌旗下的一項服務，但它不需要 Jetpack 外掛便可獨立執行。這是一個 Jetpack 品牌的獨立外掛，並且會以這種方式持續提供服務。

這個外掛是否能改進任何網站的效能？

This plugin includes a range of performance improvements, which can help almost any WordPress site perform better.

However, if your site is already extremely well optimized, Jetpack Boost may not have much room to improve it.

Jetpack Boost includes a tool for measuring your site’s Speed Score – we encourage users to try it out and see what impact it can have for them.

如何得知外掛是否發揮效果？

每個網站都有其不同之處，因此每一個效能模組對不同的網站能產生的效能改善也會因站而異，這也是我們建議逐一啟用效能模組並逐項測量效能改善的原因。現在已有多項免費工具可用於測量效能改善：

• WebPageTest.org
• web.dev/measure
• PageSpeed Insights
• GTMetrix

Jetpack Boost 控制台已內建 Google PageSpeed 測量方式。

Jetpack Boost 的速度最佳化功能是否安全？

Yes, it’s safe to try Jetpack Boost on any WordPress site.

Jetpack Boost does not alter your site’s content, it only modifies the way the content is sent to the user’s browser to allow it to display faster.

As a result, all of Jetpack Boost’s features can safely be turned off in the event of an incompatibility with your other plugins.

Jetpack Boost 與其他速度最佳化外掛比較起來如何？

Speed Optimization plugins for WordPress can be complicated and opaque for users. They often offer columns of checkboxes with little explanation, and don’t include tools to measure the impact of each change or choice users make.

Jetpack Boost aims to be as easy to use as possible, and includes a Speed Score indicator to help users immediately measure the impact of their choices.

這個外掛是否能與靜態頁面快取搭配使用？

當然可以！如果網站已安裝如 WP Super Cache 或 W3 Total Cache 等外掛，Jetpack Boost 僅會協助增加網站效能。請注意，必須在清除快取後，才會看到 Jetpack Boost 的效能改善。

如果網站資料庫龐大，Jetpack Boost 能讓網站較快載入嗎？

Jetpack Boost does not include any optimizations that target large databases at this time. However, watch this space – we are always looking for new ways to help our users perform better.

Jetpack Boost 是否能處理圖片最佳化？

Jetpack Boost can help sites with large images perform better through lazy-loading, preventing images from loading until they are scrolled into view.

Additionally, its Image CDN feature automatically converts your images to more modern web formats, resulting in smaller image file sizes without a loss in quality.

Jetpack Boost 是否相容於其他快取及速度最佳化外掛？

With few exceptions, Jetpack Boost has no problems running alongside most caching and speed optimization plugins. As a guideline, we don’t recommend enabling the same feature in multiple optimization plugins.

For example, if two plugins attempt to defer your non-essential JavaScripts, then they may end up conflicting with each other and cause display problems on your site.

If you run into compatibility issues, please do let us know. You can drop us a line on the Jetpack Boost Support Forums at any time.