Page speed is a critical factor that can either enhance or hinder the performance of your business website. Complying with essential web vitals such as page speed is pivotal for achieving higher search engine rankings. Conversely, slow-loading pages can result in a 4% reduction in website conversion rates for every additional second of loading time. Given that images significantly impact page load times, optimize WebP image file sizes can substantially improve the loading speed of your website, whether accessed via mobile or desktop devices.
This is where WebP images come into play. Since Safari, the primary web browser for iPhones, started providing full support for WebP in 2022, this modern image format has come closer than ever to becoming the standard photo format of the web.
In this guide, we will assist you in determining whether you should implement WebP images on your website.
What Is a WebP File?
In 2010, Google introduced the WebP file format with the aim of creating the fastest-loading image format on the internet. This innovative format combines the finest elements of three of the most popular image formats—JPG, PNG, and GIF—into a single, size-optimized file. WebP image files come equipped with a range of features, including:
- Lossless image compression*
- Lossy image compression**
- Metadata with XMP and EXIF
- Color Profile (ICC profile) *Lossy image compression significantly reduces file sizes by sacrificing image quality. During compression, an algorithm permanently removes data from the image, resulting in a decrease in image clarity and detail. JPGs are the most widely recognized lossy file format.
**Lossless image compression minimally reduces file size while preserving the original image quality. No image data is lost during compression (except for unnecessary camera metadata). PNGs are the most widely recognized lossless file format.
Pros of WebP Files
When and why should you consider leveraging the unique features and speed advantages of WebP? Here are several compelling reasons and optimal use cases for adopting WebP:
NATIVE TO THE WEB
WebP stands out as a file format designed exclusively for web graphics, distinguishing it from JPGs, initially created for compressing digital camera files.
Max Riffner, the Creative Director at Hurrdat Marketing, asserts, “Anything that’s native to the web is bound to outperform.” According to Riffner, “It’s just a matter of time before [WebP] becomes the default format, especially for web-based photography.”
OPTIMIZES PHOTO & SCREENSHOT COMPRESSION
WebP’s lossy compression method outshines JPGs by delivering better-optimized file sizes, particularly for simpler images with large color blocks or areas of similar contrast. An ideal scenario for replacing JPGs with WebPs is when showcasing a collection of smaller pictures on a page, such as product photos, location images, or other non-hero images.
EFFICIENT FOR LOSSLESS AND TRANSPARENT IMAGES
In some cases, WebP outperforms PNGs of the same quality when it comes to loading lossless and transparent graphics, logos, and icons. Google software engineers noted a 45% reduction in file size while maintaining similar image quality when converting a PNG to WebP. To achieve the best results for your specific needs, be sure to fine-tune the quality and effort settings.
REDUCES ANIMATION FILE SIZE
WebPs enable you to create smaller animations on your website compared to typical GIF files. A Google-conducted study revealed that animated GIFs converted to lossy WebPs were 64% smaller, while lossless WebPs were 19% smaller. Moreover, WebPs offer greater color depth and opacity levels than GIFs.
LOSSY TRANSPARENCY SUPPORT
WebP stands as the sole image format that supports transparent images with lossy compression. This capability allows transparent photos, graphics, GIFs, and more to be compressed to smaller file sizes compared to what PNGs and GIFs typically offer.
An additional study by Google demonstrated a 60-70% decrease in file size after replacing a transparent lossless PNG with a transparent lossy WebP.
COMPLIANCE WITH GOOGLE
It’s no secret that Google rewards webmasters who adhere to Google products and best practices. Notably, Google Chrome browsers have begun automatically saving image downloads as WebP files.
This transition, combined with the common recommendations from Google Page Speed Insights to “serve images in next-gen formats” like WebP, illustrates Google’s commitment to promoting and rewarding the widespread adoption of WebP.
Cons of WebP Files
WebP images are a great way to optimize your website speed, but in some instances, you may want to opt for a more common file format.
BLURRING OF HIGH-DETAIL IMAGES
In specific cases, the compression algorithms used in JPG images may preserve complex details and a wider range of colors more effectively than WebPs. As a result, JPGs are often better suited for large, intricate hero photos or prominently featured images.
To address this limitation, a workaround is available. You can apply a single-color or black-and-white filter over a WebP image using software like Photoshop to standardize pixel colors and enhance contrast, mitigating potential blurriness.
VARIABILITY IN FILE SIZE
When working with compression, it’s crucial to strike a balance between image quality and file size, as they tend to be inversely related. Occasionally, WebP files may exhibit lower quality compared to a JPG or PNG of similar file size. In such instances, enhancing the image quality could result in a larger file size than what was initially compressed.
When faced with this issue, you have a couple of options:
- Opt for Lossy Compression: Choosing lossy compression can reduce the file size at the expense of image quality. This approach is suitable when maintaining a smaller file size is more critical than preserving the highest image quality.
- Explore Alternative File Types: Alternatively, you can consider selecting a different file format that better suits the specific image or graphic in question. Different formats may be more appropriate for maintaining quality while optimizing file size, depending on the content and its intended use.
REQUIREMENT FOR ADDITIONAL CODE FOR FULL COMPATIBILITY
Browser support for WebP has become nearly ubiquitous, but, as Max Riffner points out, many users in our base have yet to upgrade their browsers and may not do so until they acquire new computers. Consequently, these users may be unable to view WebP images. Therefore, it is considered a best practice to implement WebP fallback code for browsers and devices that do not support this file format.
Fallback codes involve utilizing various HTML tag variations, offering browsers multiple methods to interpret and load images. For WebP images, the recommended approach is to include an image source URL for a JPG or PNG version of the file. If you are using a WebP optimization plugin, the fallback codes should be automatically integrated and may resemble the example provided above. However, it’s essential to exercise caution, as the presence of multiple fallback codes could potentially negate the page speed benefits that WebP images are designed to offer.
LIMITATIONS IN EDITING SOFTWARE SUPPORT
As of February 2022, Adobe Photoshop has the capability to open, edit, and export WebP files. However, it’s worth noting that Photoshop does not have the functionality to convert non-WebP photos into the WebP format.
Several other widely-used software programs, such as GIMP, Picasa, and Blender, have also incorporated support for WebP. However, it’s important to be aware that certain less common or specialized software applications may not offer native support for importing or exporting WebP files. In such cases, users may need to explore alternative solutions or consider converting their images to WebP using other software that supports this format.
WebP vs. Other Image File Types
Choosing the best image format for the web depends on many factors. This table compares WebP features vs. other popular file types.
WebP JPG/JPEG PNG GIF Compression Type Lossy & Lossless Lossy Lossless Lossless Supports Transparency Yes (Lossy & Lossless) No Yes No Supports Animation Yes No No Yes Browser Support 98% of browsers 100% of browsers 99% of browsers 100% of browsers Best Use Cases Photos, graphics, animations Photos Graphics Animations
While Google has previously compared WebP file sizes to JPG and PNG, our team undertook its own assessment to gauge WebP’s proficiency in efficiently compressing image files. Here’s the methodology we employed to ensure the utmost precision and utility in our findings:
- Selection of Use Cases: We meticulously handpicked four quintessential use cases encompassing the two primary image file types: a JPG graphic, a JPG photograph, a PNG illustration, and a transparent PNG logo.
- Initial File Size Measurement: In pursuit of consistency and alignment with web standards, we meticulously measured the file size of the original image for each distinct use case. Furthermore, we ensured that all images adhered to the web’s standard resolution of 72 dpi (dots per inch).
- Compression and Conversion Process: Utilizing the Sqoosh tool, we embarked on the compression and conversion of each original image into either lossy or lossless WebP formats. The choice between lossy and lossless conversion was determined by our quest for the ideal equilibrium between image quality and file size. Our ultimate objective was to attain final file sizes below the 100KB threshold, a criterion in accordance with Google’s maximum image size standard. Additionally, we adhered to the highest “effort” settings, which allowed for the slowest compression setting to achieve the most favorable outcomes.
- Analysis of Percentual File Size Alteration: To quantitatively gauge the page speed enhancements facilitated by WebP images across each unique use case, we conducted a comprehensive analysis of the percentage change in file size. This analysis offers a tangible perspective on the practical advantages of WebP within real-world scenarios.
By adhering to this thorough methodology, we have generated results that offer meaningful insights into the comparative advantages and trade-offs inherent to utilizing WebP images, all within the context of web performance and image quality.
How to Convert Images to WebP
Converting images to the WebP format is a versatile process, and you have several tools at your disposal to facilitate this conversion. Here are the methods you can use to convert images to and from WebP, as well as between other popular file types:
- Online Compression and Conversion Tools: You can employ free online tools such as Sqoosh, Cloud Convert, or Online Image Converter to seamlessly convert images to and from the WebP format. These user-friendly web-based platforms provide a convenient way to handle image format transformations.
- Utilize Your Computer’s Built-In Software: Many computer operating systems come equipped with built-in software for image conversion. Please refer to the following sections for specific instructions on how to utilize these tools effectively.
- File Converter Chrome Extension: If you’re a Google Chrome user, the File Converter Chrome extension offers a handy solution for converting images from WebP to JPG and PNG formats. This browser extension streamlines the conversion process, adding to the array of options at your disposal.
How to Upload WebP Files to WordPress
Uploading WebP images to your WordPress media library is a straightforward process, similar to adding any other image. Here’s a step-by-step guide to help you seamlessly integrate WebP files into your WordPress website:
- Access Your WordPress Media Library: Log in to your WordPress dashboard and navigate to the “Media” section.
- Choose the “Add New” Option: Click on the “Add New” button to initiate the image upload process.
- Select Your WebP Image: Choose the WebP image you wish to upload from your local storage. You can either drag and drop the file or use the file upload dialog.
- Provide Image Details: Once the image is uploaded, you can specify essential details for the WebP image, including the image title and alt text. This information enhances accessibility and SEO optimization for your website.
- Publish or Insert: After filling in the image details, click the “Publish” or “Insert” button, depending on whether you intend to publish the image in a post or simply add it to your media library.
To automate the process of converting existing WordPress JPG and PNG images to the WebP format, consider using a dedicated plugin. By utilizing a WebP plugin, you can set your preferred image quality settings, and the plugin will make intelligent decisions on which images to optimize based on file size. Additionally, the plugin will automatically incorporate a fallback code for browsers that do not support the WebP format.
This approach simplifies the integration of WebP images into your WordPress website, offering both enhanced performance and broad compatibility with varying browser capabilities.
Here are some of the top recommended WebP Conversion Plugins for WordPress:
How to Test Page Load Speed
To assess and enhance your website’s performance, consider utilizing PageSpeed Insights. This tool allows you to identify pages with slower loading times that could potentially benefit from WebP image optimizations. Furthermore, you can use PageSpeed Insights to evaluate the impact on page load speed after implementing WebP images, ensuring that your website offers an optimized and efficient user experience.
- Go to PageSpeed Insights and enter your URL into the search bar.
- Inspect the “Opportunities” Section for Specific Error Messages When using PageSpeed Insights to analyze your web page’s performance, pay particular attention to error messages related to images in the “Opportunities” section. Here are some key error messages to look out for and what they signify:
- “Serve Images in Next-Gen Formats”: This message indicates images that have the potential to be converted into modern image file formats like WebP. Doing so can significantly improve your page’s loading speed.
- “Properly Size Images”: This error message highlights images that could be resized to smaller dimensions in terms of width and height, optimizing them for a faster page load time.
- “Defer Offscreen Images”: This message suggests images that can be set to lazy load, which means they load only when they become visible on the screen. This approach contributes to an overall improvement in page speed.
- “Efficiently Encode Images”: This error pertains to images that can benefit from optimization through various encoding techniques, enhancing their loading efficiency.
By paying heed to these error messages and taking appropriate actions, you can effectively improve your website’s page load speed, providing a better experience for your visitors.