Compress JPG, PNG, and WebP Images Online — Free & Private

Large images slow down websites, eat up storage, and make email attachments bounce. The fastest way to fix it is to compress images before you use them. ResizeLab compresses JPG, PNG, and WebP images directly in your browser. Nothing uploads to a server. Nothing leaves your device. You pick your files, set a quality level, and download smaller versions in seconds.

This is a browser-based image compressor. That means your photos stay on your computer or phone the entire time. There is no signup, no watermark, and no limit on how many files you process. You can compress one image or batch up to twenty at once, choose to keep the original format or convert to JPG, PNG, or WebP, and control the exact quality level with a slider.

How to compress an image

If you have never compressed an image before, the process is simple. The tool above handles everything after you drop a file in.

1. Upload. Drag and drop your images onto the box or click to browse. You can add up to twenty at once. The tool accepts JPG, PNG, and WebP.
2. Choose quality and format. Use the slider to set quality. Lower numbers make smaller files. Higher numbers keep more detail. You can also switch the output format to JPG, PNG, or WebP, or leave it on Keep Original.
3. Compress. Click the Compress button. Each image is processed locally in your browser. You will see file size before and after for every image.
4. Download. Click the download arrow on any finished row, or use Download All as ZIP to get everything at once.

The entire process happens on your device. There is no queue, no cloud server, and no waiting for an upload to finish. A hundred-megabyte batch compresses just as fast as a single small file because nothing travels over the internet.

Why compress images?

Most people do not think about image compression until something breaks. A page loads slowly. An email bounces back. A social upload fails. Compressing images early prevents all of that.

Here are the most common reasons to compress:

• Faster websites. Large images are the single biggest cause of slow page loads. Compressing before you upload to WordPress, Shopify, or any CMS makes your site feel faster and scores better on Core Web Vitals.
• Email attachment limits. Most email services cap attachments at 10–25 MB. A few uncompressed photos can blow past that limit. Compressed images send without issues.
• Social media uploads. Platforms like Instagram, LinkedIn, and X compress your images automatically, often with worse quality than you would choose yourself. Compressing first gives you control.
• Reducing storage usage. If you keep a media library, photo archive, or backup folder, compression can cut storage needs by 50–80% with no visible quality loss.
• Improving Core Web Vitals. Google measures how fast your pages load. Large images hurt Largest Contentful Paint (LCP), one of the three Core Web Vitals. Smaller images mean better scores and better search rankings.
• Mobile loading speed. Phones often have slower connections than desktops. A compressed image loads in half the time on 4G or 3G, which keeps visitors from bouncing.

Supported formats

ResizeLab supports the three most common web image formats:

• JPG compression — the most common photo format. JPG uses lossy compression, which means you can shrink file size aggressively. Good for photographs and complex images where perfect precision is not needed.
• PNG compression — best for graphics, screenshots, and images with text or sharp edges. PNG supports transparency. Compress PNG files when you need a smaller file but still want crisp edges.
• WebP compression — the modern web format that beats both JPG and PNG for file size while keeping similar quality. WebP is supported by every major browser and is the default recommendation for new websites.

If you need to convert formats while you compress, use one of our format-specific converters:

• JPG to WebP — smaller files, same quality
• PNG to WebP — keeps transparency, shrinks size
• WebP to JPG — for universal compatibility
• WebP to PNG — when you need lossless output

Image compression vs resizing

Compression and resizing are related but different. Compression changes how much data an image uses without changing its pixel dimensions. Resizing changes the width and height. You can do both, or just one.

Compression reduces the file size of an image by removing redundant or less important data. A 4000×3000 JPG compressed at 80% quality might drop from 8 MB to 2 MB. The image is still 4000×3000 pixels. It just uses less storage space per pixel.

Resizing changes the pixel dimensions. A 4000×3000 image resized to 1200×900 becomes physically smaller on screen and much smaller in file size. But if the image is already the right size for your use, resizing would make it blurry or too small.

Use compression when the image is already the right dimensions but the file is too large. Use resizing when the image is too big in pixels and you need a smaller version. If you need both, use our Image Resizer to resize first, then compress. Or use the Image Converter to do both in one step.

Does compression reduce image quality?

It depends on the format and the quality setting you choose.

Lossy compression (JPG, WebP) removes some data permanently. At high quality settings like 80–90%, the difference is usually invisible to the human eye. At lower settings like 30–50%, you will start to see artifacts, blockiness, or color banding. The trade-off is smaller files for a small quality loss.

Lossless compression (PNG) keeps every pixel exactly the same. A PNG compressed at quality 100% is identical to the original. The downside is that PNG files stay larger than JPG or WebP even at maximum compression.

Our recommendation:

• For photos and complex images: use JPG at 75–85% quality or WebP at 80% quality. The file size drops by 50–70% and most viewers cannot tell the difference.
• For graphics with text, logos, or transparency: use PNG. The quality stays perfect, and the file is still smaller than the original uncompressed source.
• For the best of both worlds: use WebP. It compresses better than JPG for photos and supports transparency like PNG, all in a smaller file.

Privacy and security

Most online image tools upload your files to a remote server, process them in the cloud, and send them back. That means a copy of your image sits on someone else’s computer, even if only for a few seconds.

ResizeLab does not work that way. This tool is browser-based. Your images are processed locally using your device’s own CPU and memory. Nothing uploads. Nothing stores. Nothing transmits. Your files never leave your device, which means:

• No server can see your images
• No data breach can expose your files
• No terms of service govern your content
• No internet connection is needed after the page loads

This is especially useful for sensitive images: client work, product photography, ID documents, medical scans, or anything you would not normally trust to a third-party cloud service.

Frequently asked questions

Is image compression free?

Yes. ResizeLab is free to use. There is no signup, no credit card, and no premium tier. You can compress as many images as you want.

Can I compress images on mobile?

Yes. The tool works on any modern browser, including Safari on iPhone and Chrome on Android. Just open the page, tap browse files, and select photos from your camera roll.

Does image compression reduce quality?

Only if you choose a low quality setting on a lossy format like JPG or WebP. At 75–85% quality, the visual difference is usually invisible. PNG compression is lossless, so quality stays perfect.

What is the best image format for web use?

WebP is the best all-around choice for most websites. It compresses better than JPG for photos, supports transparency like PNG, and is supported by every major browser. For maximum compatibility with older systems, JPG is still the safest fallback.

Can I compress PNG without losing transparency?

Yes. PNG compression is lossless. Transparency is preserved exactly. If you want a smaller transparent file, you can also convert PNG to WebP, which supports transparency and compresses much smaller.

How much can image compression reduce file size?

It depends on the original format and content. Photos in JPG typically shrink by 50–80% at 80% quality. WebP often beats that by another 20–30%. PNG compression reduces file size by 20–50% without any quality loss. Graphics with flat colors compress more than photos with fine detail.

What is the difference between this compressor and the image converter?

The Image Converter lets you convert between formats, resize, and adjust quality all at once. The compressor focuses purely on shrinking file size while keeping the same dimensions. Use the converter when you need format conversion or resizing. Use the compressor when the dimensions are already right and you just need a smaller file.

Related tools

• Image Resizer — change dimensions while keeping quality
• Image Cropper — crop to exact dimensions or aspect ratios
• Image Converter — convert between JPG, PNG, WebP, AVIF, GIF, and BMP
• JPG to WebP — convert and compress in one step
• PNG to WebP — keep transparency, shrink file size