How to optimize pictures when optimizing websites

Beijing website construction Shangpin China: SEO website optimization In fact, image optimization also accounts for a large part. It is an important part of SEO website optimization. A good image optimization can not only improve the loading speed of the page, but also speed up the retrieval speed of the search engine to include more Website production Pages, and through conscious optimization of images, can also bring a certain amount of traffic through images, which benefits many parties. I will talk about how to optimize the pictures based on my personal experience

1. Add alt tag and Images should be lossless compressed

We know that if there are many pictures in a page, the opening speed of the page will be slow, that is, the loading speed of the page will be slow, especially for some picture stations, the pictures should be properly compressed, so that the loading speed of the page will be much faster. Of course, the compression of pictures is best done without loss, Now there are many such lossless compression tools on the Internet. You can find them by checking Baidu. The compression we are talking about is carried out without affecting the whole. If some pages have high requirements for image quality, the compression rate should be as small as possible so as not to affect the user experience, so this is also a compromise problem. You can make necessary treatment according to the actual situation of the page.

The ALT tag must be added to some important images on the website, so that search engines can know what the theme of the image is, so that when searching for images, they can give you a certain ranking, and the ALT tag is also a good guide for users. When users place their mouse over the image, the content in ALT will be displayed to users, In particular, when there are some problems with the image and it cannot be accessed, the role of ALT becomes more apparent. The text content in ALT will be displayed directly where the image is displayed, which plays a good role in prompting and understanding the context.

2. Try to show some meaningful words around the picture

When a search engine judges the subject of an image, it will refer to the content around the image, so we should try to show some descriptive words around some important images to help the search engine understand the image, such as the top, bottom, left and right of the image, and try to show some content related to the subject of the image, This is relatively friendly to search engines.

3. Specify the height, width and Use CSS Sprites technology (image merging)

When a page loads an image, if the width and height of img are not set in the page code (regardless of the number of concurrent downloads from different browsers), the browser will continuously calculate the instant width and height of each image during the loading process until the image is completely displayed. When the width and height are set, the width and height of the image to be loaded can be reserved in advance in the information returned by the browser, so that the browser can free up time and download other images concurrently. This is why setting the width and height of the image can slightly improve the speed of page opening. Of course, the more the total number of pages is, the more obvious the change in loading will be for sites with a large number of page images or website images.

CSS Spreads is actually to integrate some background images in a web page into an image file, and then use the combination of CSS "background image", "background repeat", and "background position" to locate the background. The background position can accurately locate the position of the background image with numbers. This can reduce the number of images as much as possible, thus reducing the number of requests from images to the server, thus speeding up page loading.

This article is written by Beijing website production Company Shangpin China //ihucc.com/ release