If your website is loading slowly and you don't know how to fix it, this guide will teach you step by step how to troubleshoot the reasons for slow website loading and optimization techniques.
Global Ping Test
Website: Recommended 10 Global Free Website Speed Test Tools
Local Ping Test
Use the local ping command to check the connection time to the server and packet loss situation. A good speed data center should have a packet loss rate of no more than 1%, a low ping value, and a consistent ping value.
Troubleshooting the Reasons for Slow Website Loading:#
1. Insufficient Server Performance#
The speed of the server space is the hardware foundation for fast website loading and a prerequisite. Otherwise, even if your website pages are designed to be very "slim," the loading speed will still be compromised.
Solution: Contact your hosting provider for assistance or switch providers.
Upgrade to a more efficient host, such as VPS or dedicated servers, to avoid resource competition.
2. Bottleneck Issues between Telecom and Unicom#
- If the loading speed of the space is inconsistent, sometimes fast and sometimes slow, or even sometimes inaccessible, that indicates instability in the space. You need to contact your hosting provider for assistance or switch providers.
- If the loading speed is fast in some locations and slow in others, it may be a network line issue.
Telecom users accessing websites hosted on Unicom servers and Unicom users accessing websites hosted on Telecom servers will generally experience slower loading speeds.
Solution: If purchasing space, it is recommended to buy dual-line or multi-line space. This is not a new concept; most virtual hosting providers offer dual-line or multi-line space, which may be slightly more expensive but is worth it from a user experience perspective.
3. Server Location#
The farther the server is from the user’s physical location, the longer the data transmission time.
For example, servers located in the United States have slower access speeds for users in Japan.
Use a CDN (Content Delivery Network): A CDN can provide services based on the user's location, speeding up data transmission and reducing latency.
Enable CDN caching.
Enable browser caching and compression: Configure the server to enable browser caching and Gzip compression to reduce data transmission volume and improve loading speed.
4. Website Security Issues#
Poor website security may lead to attacks or encounters with malicious crawlers, which can affect normal user access and increase loading times.
5. Identify Issues from the Website Itself#
Website issues include website program design, webpage design structure, and webpage content.
-
Website Program Design:
You can consult professionals in program design to check if the program's design structure is reasonable.
-
Webpage Design Structure:
-
If there are statistical codes, online customer service, or other JS codes in the website, check if they are placed at the end of the webpage code. Solution: It is best to place them at the end of the webpage code so that these codes execute only after the website code has finished loading.
-
There may be erroneous code.
Erroneous code that keeps loading or blocking can affect website speed.
Another situation is when special effect JavaScript code is copied from other websites, which may be incomplete and contain many webpage errors, causing slow website loading.- Try to minimize JavaScript effects.
-
-
Webpage Content:
-
Check if there are many large images on the webpage. You can use graphic software like Photoshop or Fireworks to reduce the image size, slightly lowering the image quality, and find the best ratio between image quality and size.
-
Check if there are large Flash files on the webpage.
-
Some users like to add music to the webpage, so that background music plays as soon as the user opens the website. It is best to avoid such practices.
-
Excessive quoting of content from other websites. For example, if you quote images or other content from other websites, if that website is slow or the page no longer exists, the loading speed of the webpage will be even slower.
-
Methods to Optimize Loading Speed:#
1. Optimize Images#
Optimizing images includes reducing the number of images, lowering image quality, and using appropriate formats.
- Reduce the number of images: Remove unnecessary images.
- Lower image quality: If not very necessary, try lowering the image quality, especially for JPG format. Reducing by 5% may not show much change visually, but the file size reduction can be significant.
- Use script files instead of effects: Use JavaScript code to achieve effects, which only adds a few bytes.
2. Choose Image Formats#
Use WebP format for images, as it has good compression effects.
3. Optimize CSS#
Sometimes when writing CSS, we may use verbose statements, such as:
Code:
margin-top: 10px;
margin-right: 20px;
margin-bottom: 10px;
margin-left: 20px;
You can simplify it to:
margin: 10px 20px 10px 20px;
Or this:
<p class="decorated"> A paragraph of decorated text</p>
<p class="decorated">Second paragraph</p>
<p class="decorated">Third paragraph</p>
<p class="decorated">Fourth paragraph</p>
Can be contained in a div:
<div class="decorated">
<p>A paragraph of decorated text</p>
<p>Second paragraph</p>
<p>Third paragraph</p>
<p>Fourth paragraph</p>
</div>
4. Add a Slash at the End of URLs#
For some URLs, such as http://www.baidu.com/512, when the server receives a request for such an address, it needs to spend time determining the file type of this address.
If 512 is a directory, it is better to add a slash at the end of the URL to make it http://www.baidu.com/512/, so the server can immediately know to access the index or default file in that directory, thus saving loading time.
5. Specify Height and Width#
When you add images or tables to a webpage, you should specify their height and width parameters.
If the browser does not find these two parameters, it needs to download the image while calculating its size. If there are many images, the browser needs to continuously adjust the page. This affects both speed and user experience.
When the browser knows the height and width parameters, even if the image cannot be displayed temporarily, there will be space reserved for the image on the page, allowing the rest of the content to continue loading. This makes the website loading speed faster and improves the browsing experience.
6. Reduce HTTP Requests#
When a user opens a webpage, the browser sends many object requests (images, scripts, etc.). Depending on network latency, each object's loading may be delayed. If there are many objects on the webpage, it can take a lot of time.
Therefore, reduce the burden of HTTP requests. How to reduce the burden?#
-
Remove unnecessary objects.
-
Combine two adjacent images into one.
-
Merge CSS files.
7. Other Small Tips#
- Remove unnecessary loading items.
- If you have embedded widgets from other websites, choose fast ones if possible.
- Try to use images instead of Flash, which is also beneficial for SEO.
- Static content can be made static to reduce server load.
- Place statistical codes at the bottom of the page (or use lazy loading).