Image Format Comparison: PNG vs JPG vs WEBP vs AVIF

When I started building websites, I thought image formats were simple - just save everything as JPG and call it a day. Boy, was I wrong. After years of dealing with slow-loading pages and blurry images, I learned that choosing the right format can make or break your website's performance.

Why Image Formats Matter

Here's the thing: the wrong image format can triple your page load time. I've seen beautiful websites become unusable because someone used PNG for every photo, or JPG for every logo. Each format has its sweet spot, and knowing when to use what can save you (and your visitors) a lot of frustration.

When to use JPG:

• Real photos (like from your camera or phone)
• Images with lots of colors and gradients
• When file size matters more than perfect quality

JPG has been around forever, and for good reason. It's great at compressing photographs while keeping them looking decent. The trade-off? It throws away some image data to make files smaller.

The catch: Never use JPG for logos, text, or simple graphics. They'll look fuzzy and unprofessional. I learned this the hard way when a client's logo looked terrible on their new website.

Real-world tip: For web photos, I usually set JPG quality to 85%. It's the sweet spot between quality and file size.

When to use PNG:

• Logos and graphics with sharp edges
• Images that need transparency (like icons)
• Screenshots with text
• When you need pixel-perfect quality

PNG is like the perfectionist of image formats. It doesn't throw away any data, so your images stay crisp. The downside? File sizes can get huge, especially for photos.

I use PNG for all logos and icons on websites. Yes, the files are bigger, but logos need to look sharp at any size.

Pro tip: If your PNG file is massive, try reducing the number of colors first before switching to JPG.

When to use WEBP:

• Modern websites where you control the hosting
• When you need smaller files without losing quality
• Mobile-first websites

WEBP is like getting the best of both worlds - JPG's small file sizes with PNG's quality. Google created it, and it's becoming the standard for modern web development.

The reality check: Some older browsers don't support it yet. I always keep JPG/PNG backups just in case.

Here's what I do: I convert all my images to WEBP for modern browsers, but my website automatically falls back to JPG/PNG for older ones.

When to use AVIF:

• Cutting-edge websites
• When file size is critical
• Progressive web apps

AVIF is even newer than WEBP and promises even smaller files. It's exciting, but I'm cautious about using it widely yet.

My honest take: Unless you're building something very modern and your audience uses the latest browsers, stick with WEBP for now.

Here's my simple process for choosing formats:

1. Is it a logo, icon, or screenshot? → PNG 2. Is it a photo for a modern website? → WEBP (with JPG fallback) 3. Is it a photo for email or older systems? → JPG 4. Do you need transparency? → PNG 5. Is file size critical and you're feeling adventurous? → Try AVIF

Mistake #1: Using PNG for everything I get it - PNG looks perfect. But a 5MB photo will make your website crawl. Use JPG for photos, PNG for graphics.

Mistake #2: Over-compressing JPGs Setting JPG quality to 10% might make tiny files, but they'll look terrible. Find the balance - usually around 70-85% works well.

Mistake #3: Ignoring mobile users Mobile users often have slower connections. Test your images on a phone with slow internet. If they take forever to load, they're too big.

Mistake #4: Forgetting about retina displays High-resolution screens need higher-resolution images, but that doesn't mean you need massive files. Use responsive images that serve the right size for each device.

For batch conversion: I use online tools for quick jobs, but for serious work, I prefer desktop software that gives me control over quality settings.

For automatic optimization: Many website platforms now automatically convert images to the best format. WordPress, for example, can handle WEBP conversion automatically.

For testing: Always check your images on different devices and internet speeds. What looks fine on your fast office internet might be painfully slow for visitors.

New formats keep appearing, each promising smaller files and better quality. While it's tempting to jump on every new format, I stick to what works reliably across most browsers and devices.

My advice? Master JPG, PNG, and WEBP first. They'll handle 95% of your needs. Once you're comfortable with those, then explore newer formats.

Recently, I optimized a client's photo gallery. The original version used PNG for everything - file sizes were huge and the page took 30 seconds to load.

After converting photos to WEBP and keeping only logos as PNG, the same page loaded in 3 seconds. Same visual quality, but 10x faster.

Don't overthink it. Start with these basics:

• Photos → JPG (or WEBP if your website supports it)
• Logos and graphics → PNG
• When in doubt, test both and see which works better

The "best" format is the one that gives you good quality at a reasonable file size for your specific use case.

Ready to optimize your images? Try our free image conversion tools to convert between formats effortlessly.