Images optimization is an essential element in speeding up a website while retaining the quality of the posted contents. Images are regarded as the most traffic-heavy resources apart from movie clips and rich multimedia. Our guide lists the essential tips and techniques to guarantee that your site will load fast, bug-free, and invite in even more visitors.
Tip #1: Compress Your Images
Choosing an appropriate format is not a very easy task. This will depend on the type of content website owners want to focus on. While most common formats are versatile and can be used for various purposes, many formats are actually designed for specific purposes.
Web compression will optimize the image size based on discrete operations that apply mathematical formulas and algorithms. As a result of this, the file size will be lowered. There are two main types, which are distinguished — lossy compression in which the smaller file size will result in a loss of the quality. On the other hand, there is also lossless compression, which does not show any evident loss of quality. Depending on the purpose and image type, different options may be considered.
For example, small objects and web elements are generally processed with lossy compression to load as fast as possible, while lossless is applied to high-resolution files.
Such files are generally compressed using graphics editors that support the given formats. Usually, this is done via the Save for Web option, which applies unique algorithms to optimize the file size further. In most cases, the users will have a visible image quality slider adjusted to match the target file size. A preview panel may be shown to check for severe degradation. The users can use it to optimize the files visually.
An alternative is to use a dedicated image optimizer — they are generally available as software tools or web services.
Tip #2: Pick A Contemporary File Format
When the Internet boom began, a lot of the sites using non-compressed BMP (bitmap) files, many visitors started to disable the files loading as they could not wait minutes to wait for a single page. It is better to optimize them by relying on the JPEG or GIF file formats, which were much more suitable for web content display.
Later on, the groups that administrate them created follow-up improvements that were geared specifically for web use. Some of the popular ones who are still used today are the following:
- PNG — This is a file format, shortened for Portable Network Graphics, which has both a lossy and lossless compression mode. It is widely supported in all browsers and, compared to GIF has a higher color depths palette. PNG files also support transparency and, as such, are often part of larger sites and portals. PNG images are also widely integrated into web applications, frameworks, and even computer games.
- JPEG –This is the most popular web format which uses lossy compression. JPEG images are small, load fast, and are compatible with most software. Photographers often use such files in high-resolution as most users may not distinguish the little details in images. As such, it is not the right choice for high-detail content like diagrams and charts where compression can be critical. While the older format has the extension of JPG or JPEG, there is a much more improved version called JPEG 2000, otherwise known as JP2. This new version can be used for motion graphics and gives website administrators the choice to use lossless or lossy compression and upgraded high-dynamic range. JPEG XR is another short upgrade for JPEG extended range and is a format mainly used for continuous tone photographic images.
- GIF — This file format, which is famous for its animation functionality, is short for Graphics Interchange Format. It was specially designed as an alternative to the older formats. It generates small file sizes using lossless compression. GIF has been widely used for producing short videos and “memes” which are also posted on popular social networks. They also support an option called interlacing, which is storing rows of pixels so that the rendered files are of lower quality. This mechanism is widely used when visitors have a slow connection. The smaller files are optimized for such purposes.
- SVG — This is one of the most popular vector graphics formats. It is based on an optimized XML code and specifies the image as a set of small points across the given coordinates. As this is a vector-based format and based on the optimized XML code that the browsers can interpret, they can be inserted using the “<svg>” tag or inserted as an image file. SVG files are very appropriate for displaying complex charts to devices with different screen sizes.
- TIFF — This is another popular raster graphics format which is short for “Tagged Image File Format” which is primarily used for uploading and shared documents and scanned photos. It is used to optimize files for archive purposes. For this reason, the file size will be significantly larger than ordinary files. It includes a different set of compression methods that can be set by the web developers. These files can also contain detailed metadata. As a result, most of the TIFF files are uncompressed.
- WebP — The WebP image is a new file format that is optimized for web usage. It is based on the VP8 video codec transmitting images with lossless compression. They are used for animations and motion graphics, and the lossy images are about 25% smaller than comparable quality JPEG files. They are now compatible with most desktop and mobile web browsers; however, older versions may not be able to view the files. The specification is open-source, which means that developers can easily add support for it.
Tip #3:Use the Right Dimensions
Website administrators should optimize place image files based on correct dimensions. Contemporary site-building guidelines specify that certain placeholders and logos use certain dimensions to provide the best visibility.
As a rule, higher resolution images will result in larger file sizes — very large files in the main elements and headers may result in significant loading disruptions. Many modern search engines determine the site’s score by the loading speed, as it is regarded as an important factor. A site with slow loading elements will decrease the search engine ranking.
When it comes to the dimensions, web graphics measure it in pixels. There are standard sizes, for example, the typical large-scale object may be displayed in a 640×480 image which can be scaled either up or down depending on the case.
Another rule which is generally used by website administrators is the fact that most computer monitors display only 72 or 92 dpi. This is a value showing the density (dots per inch) of the image files, in practice, anything higher than that may be overkill. Any modern photo editing software can be used to check and edit the resolution and optimize it for web usage. These tips which are recommended for web site usage:
- Color Profile and Mode — The files that are to be published with an RGB color mode, which is the opposite of the CMYK model, which is used for print media. Most desktop and mobile software will render it correctly. Also, set the sRGB color profile, which has the widest compatibility across all programs.
- File Size — To optimize images file size, they need to be less than 500 KB for general usage.
- Text on Images — Whenever text needs to be added on a given image, it is recommended that it is placed overlay. This will optimize the text to be searchable by machine methods and also makes it faster to load.
- Image Tags — Specifying image tags using the alt will not only optimize the images for greater SEO visibility, but also for better page integration. Most images optimized this way will also display the alt text when the mouse hovers over them, which makes them organically integrated into the pages.
More Essential Tips by Howtohosting.guide
To optimize a given site, the website owners should categorize it to find its main purpose. While the advice mentioned above is suitable for general-purpose sites, other methods can be undertaken.
For example, companies should add in a favicon that meets the recommended size of 300×300, which will be rendered by the browsers to 16×16 pixels. The favicon should be placed in a respective named file bearing the .ico or .png extensions to optimize it for the search engine bots.
Animated GIFs should also not exceed a certain pixel limit as this can significantly slow down the page loading speed. Website administrators should scale them down to the target size manually.
Check back on this article as we update it further with more tips on image optimization.