Image Format Guide: When to Use JPEG, PNG, WebP, AVIF

You saved an image. But which format did you pick? JPEG, PNG, WebP, AVIF... they all store pictures, but they do it in very different ways.

The wrong format can bloat your file size, kill your page speed, or strip away details you needed to keep. The right format gives you small files that look great and load fast.

This guide covers everything you need to know. What each format does best, where it falls short, and how to pick the right one every time. No guessing required.

What Are the Main Image Formats and How Are They Different?

There are four formats that matter most today. Each one was built to solve a different problem.

JPEG has been around since the early 1990s. It uses lossy compression, which means it throws away some data to make files smaller. JPEG handles photos well because it was built for them. It supports millions of colors and produces small file sizes. But it has no support for transparency. And every time you re-save a JPEG, it loses a bit more quality.

PNG came along in the mid-1990s as a free replacement for GIF. It uses lossless compression, so no data is ever lost. PNG supports full transparency, which makes it perfect for logos, icons, and graphics that need to sit on top of other content. The trade-off is larger file sizes, often 3-5 times bigger than JPEG for the same photo.

WebP was created by Google in 2010. It supports both lossy and lossless compression in a single format. WebP also handles transparency and basic animation. Files are about 25-35% smaller than JPEG and up to 26% smaller than PNG at the same quality. All modern browsers support it.

AVIF is the newest option, based on the AV1 video codec. It offers the best compression of all four formats. AVIF files can be up to 50% smaller than JPEG with no visible difference. It supports transparency, HDR, and wide color ranges. Browser support has grown fast and now covers over 93% of users.

When Should You Use JPEG?

JPEG is the safe choice for photos. It works everywhere, on every device, in every browser, in every app. Nothing reads more formats than JPEG.

Use JPEG when you need maximum support. Email clients, social media platforms, and older systems all handle JPEG without issues. If you're sending photos to someone and you're not sure what they'll open them with, JPEG is your safest bet.

JPEG also works well for print. Many print shops prefer JPEG files. Design software and photo editors all read and write JPEG natively.

Here's where JPEG falls short:

• No transparency. Any transparent areas get filled with a solid color (usually white).
• Quality loss on re-saves. Each time you edit and save a JPEG, it recompresses. Quality drops a little each time. After several rounds of editing, you'll see blocky patterns and color banding.
• Larger files than WebP or AVIF. At the same visual quality, JPEG files are 25-50% bigger than modern formats.

The bottom line: use JPEG when you need every device and platform to open your file. It's not the smallest or the best, but it works everywhere.

When Is PNG the Right Choice?

PNG shines in three situations: transparency, sharp edges, and graphics.

Transparency is the biggest reason people choose PNG. If your image needs to float on top of a colored background, or blend into a web page design, you need a format that supports alpha channels. PNG handles both full transparency and partial transparency perfectly.

Sharp edges and text stay crisp in PNG. Because PNG uses lossless compression, it never smudges edges or blurs details. Screenshots, diagrams, charts, and images with readable text all look better as PNG. JPEG would blur the text and create fuzzy artifacts around sharp lines.

Graphics with few colors compress very well as PNG. A logo with five colors might be only 5-10 KB as PNG. The compression algorithm finds repeating color patterns and stores them very tightly. Simple graphics often end up smaller as PNG than as JPEG, because JPEG struggles with flat colors and hard edges.

Where PNG is a poor choice:

• Photos. A photo saved as PNG can be 5-10 times larger than the same photo as JPEG. All that lossless precision is wasted on photos where your eye wouldn't notice the difference anyway.
• Large images for the web. PNG file sizes add up fast. A page with five large PNGs can easily top 5 MB.

Use PNG for logos, icons, screenshots, UI graphics, and anything with transparency or text. Don't use it for photographs.

Why Should You Switch to WebP?

WebP gives you the best of both worlds. It compresses photos better than JPEG and handles transparency better than PNG. All in one format.

The file size savings are real. A photo that's 200 KB as JPEG drops to about 140 KB as WebP at the same quality. That 30% savings adds up across a whole website. A site with 50 images saves over 3 MB just by switching to WebP. That means faster page loads and lower hosting costs.

WebP supports transparency too. A transparent logo that's 80 KB as PNG might be only 55 KB as WebP. You keep the transparency and still save 30% on file size.

Browser support is no longer an issue. Chrome, Firefox, Safari, Edge, and Opera all support WebP. That covers over 97% of web users. The only holdouts are very old browser versions that most sites no longer need to worry about.

WebP also supports animation, like GIF but with much better compression. An animated WebP is often 50-80% smaller than the same GIF.

So why doesn't everyone use WebP for everything? A few edge cases remain:

• Print workflows still expect JPEG or TIFF. Some print shops don't accept WebP files.
• Social media platforms may re-encode WebP uploads to JPEG.
• Photo editing software has varied WebP support. Photoshop and GIMP handle it fine. Some older tools don't.

For the web, WebP is the go-to format. It's smaller than JPEG, more versatile than PNG, and supported almost everywhere.

Is AVIF Worth Using Right Now?

AVIF delivers the smallest file sizes of any format available today. But is it ready for daily use?

The compression numbers are impressive. AVIF can produce files that are 50% smaller than JPEG and about 20% smaller than WebP at the same visual quality. A hero image that's 300 KB as JPEG might be just 150 KB as AVIF. On a media-heavy page, those savings are huge.

AVIF also supports features that JPEG and WebP can't match. HDR (High Dynamic Range) lets images show a wider range of brightness. Wide color gamut support means more vivid, accurate colors. These features matter for photography and high-end visual content.

Browser support is strong and growing. Chrome, Firefox, Edge, and Safari all support AVIF now. Over 93% of web users can view AVIF images without any issues.

There are a few trade-offs to know about:

• Slower encoding. Creating AVIF files takes longer than JPEG or WebP. A batch of 100 photos might take 2-3 times longer to convert to AVIF. This matters if you're processing thousands of images.
• Older device support. Some devices running outdated operating systems or browsers still can't display AVIF. If your audience includes many users on older hardware, you'll want a fallback.
• Software support. Some image editors and platforms don't read AVIF yet. You may need to keep a JPEG or PNG copy for editing.

For websites and apps targeting modern browsers, AVIF is worth using. Pair it with a WebP or JPEG fallback for older browsers. The HTML <picture> element makes this easy. Serve AVIF to browsers that support it and JPEG to those that don't.

How Do You Pick the Right Format for Your Project?

Choosing a format comes down to three questions. What does the image show? Where will it be used? Who will view it?

For photos on a website: Start with AVIF. It gives you the smallest file with the best quality. Add WebP as a fallback, and JPEG as the final safety net. Your server can deliver the right format to each browser.

For product photos in an online store: WebP is often the best single format. It's small, looks good, and works in every modern browser. If you serve thousands of product images, the file size savings from WebP or AVIF add up to real money in bandwidth costs.

For logos and icons: PNG or SVG. These graphics need sharp edges and often require transparency. If file size matters, convert to WebP. Avoid JPEG for logos since it blurs sharp edges and creates artifacts.

For screenshots and tutorials: PNG keeps text sharp and readable. If file size is a concern, try WebP with high quality (90%+). Never use JPEG for screenshots with text.

For email attachments: JPEG. Not every email client supports WebP or AVIF. JPEG works in all of them. Resize to a reasonable width (1200-1600 px) first, then save at 80% quality.

For social media: Check what the platform accepts. Most handle JPEG and PNG. Some now accept WebP. Few support AVIF. When in doubt, use JPEG for photos and PNG for graphics.

For print: JPEG or TIFF at full resolution. Print workflows rarely support WebP or AVIF. Keep your source files in PNG or TIFF and export to JPEG for the printer.

Here's a quick cheat sheet:

Use case	Best format	Why
Web photos	AVIF > WebP > JPEG	Smallest files, best quality
Logos, icons	PNG or SVG	Sharp edges, transparency
Screenshots	PNG	Lossless, text stays crisp
Email photos	JPEG	Works everywhere
Animations	WebP > GIF	Smaller files, better quality
Print	JPEG or TIFF	Industry standard

What Happens When You Convert Between Formats?

Converting images sounds simple, but there are a few things that can go wrong if you're not careful.

Lossy to lossy adds quality loss. Converting a JPEG to WebP (or the other way around) means the image goes through lossy compression twice. The second round removes more data. You won't always see the difference with one conversion, but it's best to start from the highest quality source you have.

Lossless to lossy is fine. Converting a PNG to JPEG or WebP works great because you're starting with full quality. The lossy compression only runs once, so you get clean results.

Lossy to lossless doesn't restore quality. Saving a JPEG as PNG doesn't bring back the data that JPEG already threw away. You just get a bigger file with the same quality. This is a common mistake.

Transparency can be lost. If you convert a transparent PNG to JPEG, the transparency disappears. The clear areas fill with a solid color (usually white or black). Make sure your target format supports transparency before converting.

Metadata may change. Some formats store metadata like camera settings, GPS location, and creation date. Converting between formats can strip or alter this metadata. If you need to keep EXIF data, check your converter's settings.

The safest approach: always convert from the highest quality source. If you have the original PNG or RAW file, use that as your starting point. Don't convert from a JPEG that was already compressed.

How Can You Serve Multiple Formats to Different Browsers?

Modern web development has a clean solution: the HTML <picture> element. It lets you list several versions of the same image. The browser picks the first format it supports.

Here's how it works. You provide AVIF first (smallest), then WebP (wide support), then JPEG (universal fallback). The browser reads the list from top to bottom and uses the first one it can display. Older browsers that don't understand <picture> fall back to the plain <img> tag with your JPEG.

This approach gives you the best of all worlds. Users with modern browsers get AVIF and save bandwidth. Users with slightly older browsers get WebP. And the few users on very old browsers still see your image as JPEG. Nobody gets left out.

If managing multiple file versions sounds like too much work, you have options. CDN services like Cloudflare and Cloudinary can auto-convert images on the fly. Content management systems often have plugins for automatic format conversion. And tools like ConvertIMG let you batch convert images to any format in seconds.

The key point: you don't have to pick just one format. Serve the best format each browser can handle, and everyone wins.

What Format Mistakes Slow Down Your Website?

Format choice has a bigger impact on page speed than most people realize. Here are the most common mistakes.

Using PNG for photos. This is the number one format mistake on the web. A photo saved as PNG can be 2 MB. The same photo as WebP at 80% quality is 200 KB. That's 10 times smaller with no visible difference. Swap your photo PNGs to WebP or AVIF and watch your page speed scores jump.

Using JPEG for logos and text. JPEG creates ugly artifacts around sharp edges. Your logo looks blurry. Text in images becomes hard to read. Use PNG or SVG for anything with sharp lines.

Not using modern formats at all. Many sites still serve only JPEG and PNG. Switching to WebP alone can cut total image weight by 25-35%. Adding AVIF saves even more. These are free performance wins.

Uploading huge originals. A 4000 px wide photo displayed at 800 px is wasting 80% of its pixels. Resize images to their display size before converting. A 1600 px WebP at 80% quality loads in a fraction of the time.

Skipping compression settings. Default export settings are often too high. A JPEG at 100% quality is barely better than 80% quality to the human eye, but it's 3-4 times larger. Find the quality sweet spot (usually 75-85% for lossy formats) and save real bandwidth.

Ignoring retina displays. Modern screens show 2x pixel density. An image displayed at 600 px needs a 1200 px source to look sharp. Size your images at 2x the display width, then compress. You get crisp visuals without huge files.

Ready to Convert Your Images?

Now you know which format to use and when. The next step is easy.

ConvertIMG converts your images between JPEG, PNG, WebP, and AVIF right in your browser. No uploads to external servers, no software to install. Drop your files in, pick your format, adjust the quality, and download. It takes seconds.

Whether you're switching a batch of product photos to WebP, converting PNGs to AVIF for your blog, or preparing images for email, ConvertIMG handles it all. Try it free and see how much faster your images can be.