Compress images.
Faster websites. Greener web.
Drop in your JPG, PNG or WebP images and SW3 Images finds the smallest possible file with no visible quality loss — measured, not guessed. Compress, optimize and resize your images for the web before publishing them online.
The entire compression engine is written in Rust — the same craftsmanship we put into the websites we build.
Drag & drop your images here, or click to browse
JPG, PNG or WebP · up to 30 MB each
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✓ Thanks! You can now compress up to 50 files at a time.
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SubscribeFrequently asked questions
How do I optimize images for the web?
Drag and drop up to 10 JPG, PNG or WebP images into SW3 Images (50 with the free unlock), click Compress, and download the results one by one or as a zip. SW3 Images searches for the smallest file that still looks identical to your original — typically 40–90% smaller.
Does compressing images reduce their quality?
Not visibly. Every candidate file is measured against your original with DSSIM, a perceptual metric that models human vision, and judged at the size the image is actually viewed on a web page. If quality cannot be preserved, SW3 Images returns your original file instead — it never makes files bigger.
Can I resize images as well?
Yes. Choose "Resize to max width" and set a pixel width, for example 1024. Every image wider than that is scaled down with its aspect ratio preserved before compression; images are never upscaled.
Which image formats are supported?
JPEG, PNG and WebP, up to 30 MB per image. The format never changes — a PNG in is a PNG out. JPEGs are re-encoded with mozjpeg, PNGs with imagequant and oxipng, WebP with libwebp at maximum effort.
Is it free, and what happens to my images?
SW3 Images is free and requires no account. Uploads are private, reachable only through an unguessable link, and deleted automatically after 24 hours. Metadata such as EXIF and GPS location is stripped, which shrinks files and protects your privacy.
What makes the compression algorithm special?
Most tools apply a fixed quality setting. SW3 Images instead runs a perceptually-guided search, written in Rust: it measures structural similarity in Lab color space for every candidate and picks the smallest file below a visually-lossless threshold — quality is measured, not guessed.