Image Compressor
Compress, convert & resize — runs entirely in your browser, no uploads
Drag & drop image here
PNG · JPG · WebP · GIF supported
What is Image Compressor?
An image compressor is a tool that reduces the file size of digital images while preserving as much visual quality as possible. Every time you photograph something on your phone or download an image from the internet, the file can be several megabytes in size. These large files slow down websites, consume mobile data, fill up storage, and often exceed email attachment limits.
Image compression works by analysing pixel data and removing redundant or less-important information. There are two main types: lossy compression (used by JPEG and WebP) discards some image data that the human eye barely notices, achieving dramatic size reductions — often 70–90% smaller. Lossless compression (used by PNG) reorganises data more efficiently without losing any pixels, giving smaller files that are identical to the original.
Altairys's image compressor runs entirely in your browser. No files are uploaded to any server — your images stay private on your device. It supports JPEG, PNG, and WebP formats, and gives you a quality slider so you can find the perfect balance between file size and visual quality. Compressed images are ready to download in seconds, making this tool ideal for web developers optimising site performance, bloggers preparing images, designers sharing work, and anyone who regularly works with photos.
How to Use Image Compressor
- Upload your images
Drag and drop one or multiple images onto the upload area, or click to browse your files.
- Adjust compression settings
Set the output format (JPEG/PNG/WebP), quality level (1–100), and optional resize dimensions.
- Preview the results
Instantly see the compressed file size and compare before/after quality side by side.
- Download compressed images
Download individual files or all compressed images as a single ZIP.
Key Benefits
Smaller images load faster, improving page speed scores and user experience.
All compression runs in your browser — images are never uploaded to any server.
Smaller images use less bandwidth — perfect for mobile-first websites and apps.
Compress multiple images at once and download them all in a single ZIP file.
Supported Formats
Frequently Asked Questions
Lossy compression (JPEG/WebP) does reduce some quality, but at settings above 70% the difference is nearly invisible to the human eye. Lossless compression (PNG) preserves every pixel.
WebP offers the best compression ratio for web use — files are typically 25–35% smaller than JPEG with equivalent quality. JPEG is best for photos, PNG for graphics with transparency.
A typical JPEG photo can be reduced by 60–90% with minimal visible quality loss. Results vary by image content — simple images compress more than detailed ones.
Yes. All processing happens in your browser using JavaScript. Your images are never uploaded to Altairys servers or any third party.
Yes — you can upload multiple images at once and download all compressed results in a single ZIP file.
Since processing is local, the limit depends on your device's RAM. Most devices handle images up to 20–30 MB without issues.