The speed at which the site is loaded is one of the core factors influencing the user experience and the ranking of the search engine. The data show that the conversion rate may drop by 7 per cent for each second of the time the page is loaded, and google will use load speed as an important indicator for ranking algorithms. The following are the five key directions and practical ways to optimize the speed at which the site is loaded to help you solve the performance problem from the source of the construction:
I. Optimizing resource loading: reducing requests and volume
Photo / video light quantification
Format selection: prefer to the webp/ avif format (30-50% smaller than jpeg/png volume), which can be converted by squosh or imagemagick batch。
Compression corresponds to size:
Shortpixel or tinypng to compress images to avoid uploading original camera photos (e. G. Original 3mb+ map)。
Sets the size of the picture based on the display area (e. G., the width of the banner 1920 px, automatically scaled to 750 px) and avoids the use of " big maps " 。
Lazy loating: adds a loading = "razy" attribute to long-page non-screen pictures / videos to reduce the pressure on front-screen rendering。
2. Code streamlining and consolidation
Merge css/js documents: merge decentralized css/js into single files through building tools such as webpack/vite, reducing the number of http requests (e. G. From 10 to 3)。
Remove redundancy code:
Deletes unused css classes (purgecss scans), comments and debug codes。
Avoid misuse of the framework (e. G. Simple rotation of primary js instead of introducing fullpage. Js library)。
Step on non-critical scripts: add async or defer properties to advertising, statistical codes to avoid blocking rendering。
Cache mechanisms: reducing duplication of requests
1. Browser cache policy
Configure the cache-controll response header at the server end, setting up long-term caches (e. G. 1 year) of static resources (e. G., pictures, css, js) and solving the problem of cache updates through documents such as main. Abc123. Js。
Http
Cache-control: max-age=31536,000, public, immutable
Sets short-term caches (e. G. 1 hour) for HTML files to ensure that the content is updated in a timely manner。
2. Cdn acceleration (content distribution network)
Deployment of static resources to cloudflare/akamai/ariyun cdn, near transmission using global nodes, and reduction of delays (particularly for transnational users)。
Example: independent image domain names (e. G. Img. Example. Com) are used to break the browser domain name and request limits (usually 6-8)。
Optimizing rendering performance: increasing the speed of the first screen
1. Prioritizing the loading of critical resources
Inline screen css: write the first visible css directly to HTML labels and avoid blocking external css requests for rendering。
Preload critical resources: add tags to the fonts necessary for the front screen, js files, and pull resources in advance。
HTML
Website development
2. Avoid rendering obstruction
Mark non-critical jss asymmetric or delayed (defer):
HTML
Against the front screen, javasCript uses dynamic import (e. G. React. Lace) to achieve as-needed loading。
Iv. Server and network optimization: improving response efficiency
Enable http/2 and https
Http/2 advantages: support multi-routing (individual connection for multiple requests), head compression (reduced data transfer), 50% faster than http/1. 1。
Https necessity: google uses https as a ranking signal and https connection can enable tls 1. 3 to accelerate handshake。
2. Compressed transmission content
Open the gzip/brotli compression: enabled in the nginx/apache server configuration, the css/js/HTML backlog can be reduced by 60-80%。
Nginx configuration example:
Nginx
Gzip on;gzip types text/css application/javasCript text/HTML; gzip comp level 6;
Website development
3. Optimizing database queries
For dynamic websites (e. G. Wordpress/ electrician platforms):
Clear redundant data (delete unused plugins, comment trash)。
Use the cache plugin (e. G. Wp rocket) cache page HTML to avoid each request triggering a database query。
V. Performance monitoring and continuous optimization
1. Tool detection and bottlenecks positioning
Google pagespeed insights: provides a mobile / desktop end rating, indicating specific optimisation items (e. G. "page uncompressed" "stock-up rendering")。
Lighthouse audit: run through chrome devtools to generate detailed reports containing performance, seo, accessibility。
Webvitals indicators: focus on lcp (maximum content mapping) ≤2. 5 seconds, fid (initial input delay) ≤100 ms, cls (accumulative layout deviation) ≤0. 1。
2. Phased optimization strategy
Emergency optimization item (completed within 1 week): compress pictures, enable https, merge js/css。
Progress optimization item (completed within 1 month): introduction of cdn, implementation of lazy loading, optimization font loading。
Long-term optimization: regular comparison of the effects of different optimisation programmes with webpagetest, with special adjustments for slow pages (e. G., commodity details pages)。
Field cases: optimization of comparison
Optimization
Before optimizing
Optimised
Increase effect
First page loading time 4. 8 seconds 1. 9 seconds down 60%
Picture volume total 2. 3 mb total 820kb reduction 65%
Http requests 78 32 reduction 59%
Lcp indicator 3. 9 seconds (overtime) 1. 6 seconds (green compliance) up 60%
Summary of key principles
Priority user perspective: ensure first screen content “short and flat”, delayed loading of non-essential resources。
Data-driven decision-making: quantifying bottlenecks with tools to avoid blind optimization with experience。
Technical stacks fit: selection of options according to the type of website (e. G. Static site using jamstack structure, dynamic site optimising database)。
Through system optimization of the above 5 dimensions, most websites can increase load speed by 40 to 70 per cent, while improving seo ranking and user retention rates. Remember that performance optimization is a continuous iterative process that needs to be adjusted to take into account business growth dynamics。
