About PicBrewery
PicBrewery is a free, open tool that compresses and converts images entirely inside your browser. Your images are never uploaded — they stay on your device.
What it is
PicBrewery is a one-page web application for optimizing photos and graphics. Drop in JPG, PNG, WebP, AVIF or BMP files and get compressed variants in all four modern formats side-by-side — so you can pick the smallest one that still looks right. Batch size is up to 20 files at 20 MB each, with two concurrent encodes to keep your laptop responsive.
Why optimize images?
Images are usually the single largest payload on any web page — often more than HTML, CSS and JavaScript combined. Compressing and converting them into modern formats is the fastest, lowest-risk way to speed up a site, cut bandwidth bills and improve search rankings, without rewriting a line of code.
- Faster page loads and better SEO. Image weight is the main driver of Largest Contentful Paint (LCP) and a major input to Google's Core Web Vitals. Shaving 40–60% off hero images can move LCP from the "poor" into the "good" bucket, which directly affects mobile search ranking and ad Quality Score.
- Lower bounce on mobile and slow networks. On 3G/4G or spotty Wi-Fi, multi-megabyte JPEGs delay the first meaningful paint. Visitors abandon pages that take more than ~3 seconds to render. A smaller AVIF or WebP fallback keeps your site usable on the devices where most of the traffic actually lives.
- Cheaper hosting and CDN egress. Bandwidth is the biggest variable cost for most static sites, e-commerce stores and SaaS marketing pages. Halving image weight halves image egress — often the majority of total transfer — and saves real money every month at scale.
- PWA install size and offline cache. Service-worker caches and app shells are capped in size on many devices. Smaller images mean richer offline experiences, snappier re-opens and more headroom for other assets inside the install budget.
- Smoother UX in apps and animations. Decoding giant bitmaps blocks the main thread and causes jank during scroll, route transitions and gallery swipes. Lighter files decode faster, keeping animations at 60 fps and interactions crisp on low-end hardware.
How it works
PicBrewery runs production-grade image codecs compiled to WebAssembly, executed inside Web Workers so the UI stays responsive. The same libraries that power native desktop tools are doing the heavy lifting — only the glue is JavaScript.
- JPEG — MozJPEG, the reference high-quality JPEG encoder.
- PNG — oxipng (Rust), a lossless PNG optimizer.
- WebP — libwebp from Google, both lossy and lossless.
- AVIF — libavif with the AOM AV1 encoder — the current state of the art for photo compression.
When you drop files, decoding and re-encoding happens entirely on your
device. The OffscreenCanvas API and typed arrays move pixel data
around with minimal copying. The finished blobs go straight into a download
link or a ZIP archive built in the browser with
fflate.
Privacy
Image processing is 100% client-side. Your files are decoded, re-encoded and zipped entirely inside your browser — they are never uploaded to any server, and the codec binaries are static assets. Once loaded, PicBrewery works offline.
The website itself uses privacy-respecting analytics (Google Analytics 4 and Yandex.Metrika) and may show ads (Google AdSense and the Yandex Advertising Network) to keep the project free. None of these are loaded until you opt in via the cookie banner — you can accept, reject or adjust your choice any time from the Privacy Policy page or the "Cookie settings" link in the footer.
Your preferences (theme, advanced codec settings) are saved to
localStorage on your device so they survive reloads.
Browser support
Requires a modern browser with WebAssembly, Web Workers and
OffscreenCanvas — Chrome 90+, Firefox 90+ and Safari 15+.
Older browsers see an explicit incompatibility screen.
Learn more
If you want to go deeper into image formats, start with our Image formats comparison — a practical guide to JPEG, PNG, WebP and AVIF — or open PicBrewery.
Chrome Extension
Free Chrome extension that scans any webpage, scores image weight, and shows how much faster the page would load with lighter images — then optimize in PicBrewery.
Contact us
Have questions, suggestions, or found a bug? We always welcome your feedback.
Ready to optimize?
Drop your images into PicBrewery. Everything stays on your device.