JPG vs PNG vs WebP: Ultimate Guide for WordPress Image Optimization

Your website might look stunning, but unoptimized images could secretly slow down your website. So, you need to choose the image file format correctly.

There are 3 popular image file formats, JPG vs PNG vs WebP. And it’s important to understand how each format impacts loading speed, image clarity, and storage. Otherwise, this can make or break your site’s performance. 

Each format brings unique strengths and ideal use cases. As a blogger, designer, or online store owner, you must understand when to use each image format. 

In this guide, we’ll explain each format’s strengths and ideal use cases. This will help you optimize your WordPress site like a pro.

Now, let’s get started!

Summary of JPG vs PNG vs WebP Comparison

First, here’s a quick comparison of the JPG vs PNG vs WebP file formats.  

Overview of JPG vs PNG vs WebP

When you add pictures to your WordPress website, you can choose different types of image files. The most common ones are JPG, PNG, and WebP. Each one is good for different things. Some make your website faster, and some show more detail.

So, how are they different, and which one is best for your website? Let’s take a quick look!

What is JPG?

JPG (Joint Photographic Experts Group) is a widely used image format that was first introduced in 1992. It’s the standard photo format on many devices, including digital cameras, smartphones, and computers. 

You might see both JPG and JPEG when discussing images, they’re the same thing. We only have “.jpg” because older computers used to allow only three-letter file names, so “.jpeg” was shortened. 

These days, both work the same way, and you can use either one. In our JPG vs PNG vs WebP guide, we use “JPG” because it’s more common and easier to remember, especially for WordPress users.

Most web browsers, website builders like WordPress, and image gallery plugins fully support JPEG/JPG files. It displays rich, colorful images and supports millions of colors. And this is ideal for photographs and detailed visuals. 

Besides, JPEG images typically have smaller file sizes, which helps websites load faster without sacrificing too much visual quality. According to a record, 74.2% of websites use the JPG file format.

For instance, a photo of your dog at the park. If you use JPG, then the file is small and has many colors and details, which aren’t as noticeable in other image formats.

This image format provides a good balance between image quality and file size. However, compressing JPEGs can result in some quality loss, particularly in images with less color data.

JPG uses lossy compression, which means it reduces file size by permanently removing some image data. This helps make photos load faster and take up less space, but it can slightly lower image quality, especially if the image is saved multiple times. 

Another benefit is that JPEG files are easily convertible. You can quickly change them into formats like PNG or WebP if needed.

What is PNG?

PNG, short for Portable Network Graphics, is another widely used image format on the web and is known for its high quality and versatility. It supports millions of colors, so your images will appear sharp and lifelike. According to a record, 79.2% of websites use the PNG file format.

The best part of PNG is its lossless compression. This means that when a PNG image is compressed, it keeps all of its original data and quality. So, it’s an excellent choice when you need high-quality visuals with smaller file sizes, especially for websites like WordPress.

Another major advantage of PNG is its support for transparent backgrounds. This makes it ideal for logos, icons, and other web design elements where transparency is essential.

For example, a logo like the one on our website, SiteSaga, with no white box around it. And it just floats over your website. That’s a PNG! If you saved it as a JPG, then that white box would appear.

What is WebP?

WebP is a modern image format developed by Google. It’s designed to create high-quality visuals with smaller file sizes. Also, it offers advanced lossy and lossless compression, making it more efficient than traditional formats like JPEG and PNG. 

With WebP, your websites can load faster and consume less bandwidth without sacrificing image quality. According to a record, only 16.7% of websites use the WebP image file format.

Also, 

• 96% of modern browsers fully support WebP. 
• WebP lossless files are around 26% smaller than PNG.
• Also, WebP lossless files are 25–34% smaller than JPEG.

Moreover, lossless compression in WebP ensures that no image data is lost during compression. Lossy compression reduces file size by removing some data permanently, which can slightly affect quality but results in significantly lighter images.

A key advantage of WebP is its support for animated images, a feature not available in JPEG or PNG. This makes WebP a strong alternative to the GIF format. Additionally, like PNG, WebP supports transparency, allowing for smooth, high-quality visuals with transparent backgrounds.

Additionally, since WordPress version 5.8, WebP images are natively supported. It removes the need for plugins to use this format on WordPress websites. 

All major modern browsers, including Chrome, Firefox, Safari, and Edge, support WebP.

Learn how to use WebP images on WordPress from our detailed guide. 

JPG vs PNG vs WebP: Head-to-Head Comparison

Let’s now compare JPG, PNG, and WebP side by side. 

1. File Size of JPG, PNG, and WebP

First, let’s see the file size!

File size is the amount of space a picture takes up on your computer or the Internet. Big files take longer to load, while small files open faster. 

Starting with JPG, it makes files small by removing tiny details you can barely see. For example, a photo that starts at 3 MB, saving it as a JPG might shrink it to about 300 KB. This is only one-tenth of the file size. This is why most online photos are JPGs.

For PNG, it keeps every detail, so the file stays large. If you save as PNG, then the same 3 MB photo might remain close to 2 MB. The good part is that extra weight keeps the image sharp, but makes your web page slower if you use many PNGs.

And then there is WebP. It uses newer tricks to get the best of both image formats. It removes unwanted data like JPG yet keeps edges crisp like PNG. So your 3 MB photo could drop to around 150 KB in WebP, which is half the size of a JPG, and still clear.

Final Note: If speed matters most, then WebP is usually the lightest. JPG is next. PNG is the heaviest.

2. Image Quality of JPG, PNG, and WebP

Image quality tells how clear and accurate the picture looks after you save it. If you zoom in and see fuzzy blocks, then that’s lower quality.

JPG uses “lossy compression.” That means it throws away small data forever. As you can see in the image below, at normal sizes, a photo still looks fine. But if you zoom in or save the picture repeatedly, the tiny details start to look smudged.

PNG uses “lossless compression.” No details get lost, edges stay smooth, and text stays sharp. This is perfect for graphics, screenshots, or charts where every pixel matters.

WebP mixes two modes, lossy (like JPG) and lossless (like PNG). A WebP photo often looks as crisp as a high-quality JPG but with fewer blurry bits around fine lines. For drawings or logos, WebP’s lossless mode can rival PNG clarity while trimming file size.

Bottom Line: Use JPG for regular photos, PNG for sharp graphics and text, and WebP for the best balance of quality and small file size, especially when you want clarity without the bulk.

3. Transparency and Animation Support

Transparency in images allows certain parts of the picture to be fully or partially see-through. This is especially useful when placing an image, such as a logo, on top of a background. 

For example, a transparent logo can blend into any website banner without showing an unwanted white or colored box around it.

• JPEG (JPG) does not support transparency. If you save an image with transparent areas in JPG format, then those areas will automatically be filled in with a solid color, usually white. 
• PNG was created to handle transparency. It supports complete transparency, which allows for smooth edges and varying levels of opacity. Also, it’s widely supported by all modern browsers and design tools.
• WebP also supports transparency and uses more efficient compression than PNG. This results in smaller file sizes without sacrificing visual quality. This means you get the same clean, transparent look as PNG, but your web pages load faster.

Similarly, animation refers to images that display motion, such as looping clips or moving stickers. These are commonly seen in GIFs or chat applications.

• JPEG does not support animation. It’s strictly for still, static images.
• PNG, in its standard form, also does not support animation. However, a variation called APNG (Animated PNG) can handle motion.
• You can create animated WebP files that work similarly to GIFs. They usually have smaller file sizes than GIFs and support smoother transitions, higher frame rates, and transparency. 

It’s great for lightweight animated graphics, stickers, and attention-grabbing web elements.

Bottom Line of this JPG vs PNG vs WebP Comparison:

• Use WebP whenever possible. It supports transparency and animation while keeping image sizes small and site speed high.
• Use JPEG only for standard photographs where transparency and animation aren’t needed, mainly if WebP isn’t supported in your setup.
• Choose PNG when you need precise image clarity and transparency, especially for static elements like logos, buttons, or overlays.

You can also check our article on how to optimize images without loosing quality.

Choosing the Right Format for WordPress

Picking the best picture type for every spot on your website is essential. Besides, JPG, PNG, and WebP each do a special job. When you match the image format to your website’s needs, your pages load faster, look sharper, and make visitors happy.

Below you will find three short guides, one for each format. Read them thoroughly!

1. When to Use JPG images?

Use JPG for everyday photographs and large, colourful scenes where no part of the image needs to be see-through.

Why does JPG work here?

• JPG files throw away tiny colour details your eyes can hardly notice. That makes the file light and helps pages load fast, even on slow phones.
• Every browser, old or new, understands JPG. You never have to fear that a visitor will see a broken picture.

Good spots for JPG on a WordPress site:

• A hero banner that shows a beach at sunset.
• A blog post full of family or travel photos.
• Product pictures are on a plain white page (no transparent background is needed).

When not to pick JPG?

Do not choose JPG for logos, icons, or any image that must blend into coloured backgrounds, JPG can’t keep empty, see-through spots.

2. When to Use PNG images?

Use PNG for graphics that need sharp edges, clear text, or transparent areas.

Why does PNG work here? 

• PNG keeps every pixel. Lines stay razor-straight and letters stay crisp, even after many edits.
• PNG supports full transparency, so a logo can float over any colour or pattern without showing a white box.

Good spots for PNG on a WordPress site:

• A site logo that must sit over photos, gradients, or videos.
• Tiny interface icons (shopping cart, search glass) that need perfect edges.
• Screenshots of app windows where text must remain sharp.

Because PNG files are heavy, try to keep their pixel size small. You can use an online PNG compressor like TinyPNG.

When not to pick PNG? Avoid PNG for large background photos or galleries. The file size will slow the page, so convert those images to JPG or WebP instead.

3. When to Use WebP images?

Use WebP whenever you can, especially if speed is your top goal, and fall back to JPG or PNG only when WebP is not available.

Why does WebP work here?

• WebP compresses pictures even smaller than JPG while keeping details as sharp as PNG. 
• From WordPress 5.8 onward, you can upload WebP files directly to the Media Library, just like any other image type. You no longer need special code to make them show up.
• All modern browsers, including Chrome, Firefox, Edge, Safari 14, etc., now display WebP, so most visitors will see the images without trouble.

Good spots for WebP on a WordPress site:

• Any blog post or landing page that mixes photos, graphics, or screenshots.
• Image-heavy sites (recipes, travel, fashion) where dozens of pictures appear on one page.
• Mobile-first themes where every kilobyte counts.

However, if some of your visitors use very old web browsers, like Internet Explorer 11, then they might not be able to see WebP images. 

In that case, it’s a good idea to also have a JPG or PNG version of the image as a backup. Most image optimization plugins can handle this for you automatically. They check the browser the visitor uses and show the correct image format. So everything works smoothly!

When might WebP not fit? Your hosting server lacks the Imagick or GD library to process WebP images. Ask your host to check. 

Some image editors or tools can’t open WebP files. If that happens, then it’s best to keep your original images saved as JPG or PNG so you can edit them easily. Then, when you’re ready to upload to your website, you can save a copy in WebP format just for web use.

Tips for Effective Image Optimization in WordPress

Image optimization means making your pictures smaller and faster without making them look bad. This helps your WordPress website load quickly, uses less storage, and gives visitors a better experience, especially on phones or slower internet.

If you’re new to WordPress or don’t know much about image formats, don’t worry. These tips are simple to follow and can make a big difference.

• Don’t upload huge images straight from your phone or camera. These pictures are often way bigger than you need.
• Picking the right type means your images will load faster without losing clarity.
• Compressing the image file makes it smaller without making it look bad. A compressed image loads faster and uses less space on your server.
• Use lazy loading to make images load only when someone scrolls down to see them.
• Upload WebP files directly to the Media Library (supported from WordPress 5.8).
• Use CDN (Content Delivery Network), which stores copies of your images in different places so visitors get them faster, no matter where they are.
• Don’t overload a single page with 30+ images unless you need them.
• Over time, you may upload unused or old images. They take up space and clutter your library, so declutter your image library regularly.

Frequently Asked Questions

Here are some answers to the most commonly asked questions about image file formats.

Conclusion

And that’s a wrap! So, in this article, we’ve covered a comparison between JPG vs PNG vs WebP. We hope you liked it!

If you have any more questions or suggestions about this article, then please don’t hesitate to let us know in the comments below. We’d be happy to help!

You can also check out our article on the best WordPress cache plugins to boost your site speed. Also, you might be interested in knowing the best Flickr WordPress plugins. 

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