Smaller images.
Same picture.
Lightpress uses WebAssembly to compress whole folders of images directly in your browser. Studio-grade quality, perfectly preserved colors, no uploads, and no limits.
Drop images here, or browse
JPEG · PNG · WebP · AVIF — as many as you like
Studio-grade compression, done locally
Our tool compresses your images right in your browser — nothing ever uploads to our servers. Your privacy matters to us, and this client-side approach keeps your images 100% private while utilizing your device's own hardware for incredible speed.
Perfect for web developers, photographers, and anyone who needs next-gen image formats without quality loss. By bringing powerful WebAssembly encoders directly to the web, Lightpress ensures your colors stay vibrant and your images stay sharp.
Need lightning-fast AVIFs for your website? Want to save storage space? Our tool reduces file sizes by up to 80% while retaining Display P3 color gamuts and EXIF data.
What is Lightpress?
Lightpress is a free, incredibly powerful online tool that batch-compresses images right in your browser. It supports converting JPEG, PNG, WebP, and HEIC files into modern web standards. You can drastically reduce file sizes for your website, email, or cloud storage.
Unlike older browser-based tools, Lightpress runs industry-standard C++ image encoders via WebAssembly (WASM). It handles resizing through advanced Lanczos3 algorithms to prevent jagged edges, and it offloads the heavy processing to Web Workers so your screen never freezes.
There are no file count limits, no account requirements, and no watermarks. Drop in your images, pick your quality settings, and download the hyper-optimized results.
Why compress with Lightpress?
Privacy First
All compression happens natively in your browser. Your images are never uploaded to any remote server.
WASM Powered
Uses WebAssembly to run industry-standard C++ encoders directly on your device for unmatched compression.
Perfect Colors
Automatically extracts and preserves EXIF data and Display P3 color profiles so photos never look washed out.
Zero Lag
Heavy lifting is offloaded to Web Workers, keeping your browser fast and responsive even when crunching 100+ photos.
Next-Gen Formats
Future-proof your web assets with next-generation AVIF encoding for the highest possible quality-to-size ratio.
Studio Resampling
Uses Lanczos3 mathematical filters for downscaling, preventing the jagged edges caused by standard browser resizing.
How to compress your images
- 1
Upload your images
Drag and drop multiple files onto the upload area. We support JPEG, PNG, WebP, AVIF, and even massive HEIC files directly from your iPhone.
- 2
Customize compression settings
Adjust the quality slider to control compression strength, or set a hard maximum file size. AVIF is selected by default for maximum efficiency.
- 3
Compress and download
Click Compress Images to start. Because it runs on Web Workers in the background, you can watch the before-and-after results roll in instantly without your screen freezing.
- 4
Check the results
Compare your originals with the compressed versions. Thanks to our advanced encoders, you'll see file sizes drop by 50-80% with virtually zero loss in visual quality.
Common use cases
People use Lightpress for all kinds of situations. Here are some of the most common ones.
Website optimization
Serve next-gen AVIFs for lightning-fast page loads, perfect Lighthouse scores, and better SEO.
WebEmail attachments
Bypass strict 25MB email attachment limits without sacrificing photo quality.
EmailMobile development
Shrink massive app assets to reduce download times on the App Store or Google Play.
MobileE-commerce product photos
Keep store catalogs crisp and colorful while reducing massive bandwidth hosting costs.
E-commercePhotography portfolios
Preserve the exact Display P3 color gamut of your camera while making galleries load instantly.
PhotosSaving storage space
Free up gigabytes of space on your drive or cloud storage with high-efficiency batch processing.
StorageHow next-gen compression works
Image compression works by removing data that your eyes won't realistically notice. When you lower the quality setting, encoders run complex mathematical models to group similar colors together and simplify fine details. A modern format like AVIF at quality 70 looks completely identical to the original but can easily be 70% smaller.
To achieve this directly in your browser, Lightpress utilizes WebAssembly. Instead of relying on unpredictable native browser encoders, it loads pre-compiled binaries of the world's most powerful image encoders directly into your computer's RAM, giving you flawless, consistent results across any device.
Frequently asked questions
What image formats are supported?
Lightpress accepts JPEG, PNG, WebP, AVIF, and HEIC files. You can output to original formats, or convert everything to modern web standards like AVIF or WebP for massive space savings.
How is this different from standard browser compressors?
Most local image tools just draw your photo onto an HTML canvas and export it. That method destroys color profiles, causes jagged edges on resizes, and balloons file sizes on iOS devices. We use WebAssembly to port professional-grade encoders (like MozJPEG and libavif) directly into your browser, delivering studio-quality results.
Will compressed photos lose their vibrant colors?
No. Unlike basic compression tools that strip metadata, Lightpress automatically extracts your original EXIF data (including Display P3 wide color gamuts used by modern iPhones and cameras) and securely re-injects it into the compressed file. Your colors stay perfectly accurate.
What makes AVIF better than JPEG or WebP?
AVIF is a next-generation image format developed by the Alliance for Open Media. It offers significantly better compression than WebP and JPEG at identical visual quality. If you want the absolute smallest file sizes for your website without things looking blurry, use AVIF.
Is there a limit on how many images I can compress?
No. Since all the computation happens on your own device's CPU via Web Workers, there are no server costs, and therefore no limits. You can process hundreds of images in a single session for free.
Does the resizing feature reduce quality?
When you set a max width or height, Lightpress uses a highly advanced Lanczos3 resampling algorithm. Standard tools drop pixels abruptly, causing jagged edges (aliasing). Lanczos3 smoothly blends the pixels, resulting in incredibly sharp downscaled images.
Can I set a maximum file size for compressed images?
Yes. Enter a target in kB or MB under Maximum Size. Lightpress will intelligently run a binary search under the hood, testing different compression algorithms in milliseconds until it hits the exact maximum size you requested.
Is Lightpress safe to use for sensitive documents?
100% yes. Your network connection is only used to load the website itself. The actual image processing runs entirely inside your device's memory. Your files never leave your computer, making it completely secure for private or sensitive photos.