Free online image compressor & resizer
This tool compresses, resizes and converts images directly in your browser using the HTML Canvas API. Unlike most online compressors that cap free usage at a handful of files or watermark your output, this one is genuinely unlimited and completely private — your photos are never uploaded to any server. Drop in a batch of JPGs, PNGs or WebP files, pick a quality level and an optional maximum size, and download smaller files in seconds. It is ideal for speeding up websites, shrinking email attachments, and meeting strict upload size limits without installing any software.
How to use it, step by step
Drag and drop one or more images onto the upload box, or click it to select files from your device. Choose an output format — WebP gives the best size, JPG is universally compatible, and PNG preserves transparency losslessly. Set a quality level, where lower means a smaller file; a value of 70–85% is usually invisible to the eye. Optionally set a maximum width or height to shrink large photos, with Keep aspect ratio on by default so nothing is stretched. Click Apply to All to re-encode every image with your latest settings, then download each result individually or grab the whole batch as a single ZIP archive.
Why compress images at all?
Images are usually the heaviest part of a web page, and oversized files slow everything down. Compressing hero images and thumbnails improves your Core Web Vitals — particularly Largest Contentful Paint — which in turn helps SEO rankings and keeps visitors from bouncing. Smaller files also fit inside email attachment limits and the upload caps used by government portals and job sites. Because everything is processed locally, you can compress sensitive documents, ID scans or private photos without ever trusting them to a third-party server.
Choosing the right format
WebP is the modern default: at 80% quality it is often 25–35% smaller than a JPG of comparable visual quality and it supports transparency. JPG remains the safest choice for photos when you need maximum compatibility with older software. Reach for PNG only when you need crisp, lossless transparency — logos, icons and screenshots with sharp edges — since photographic content compresses far better as JPG or WebP. Converting a heavy PNG screenshot to WebP or JPG frequently cuts its size dramatically with no perceptible loss.
Resizing for the web
Resolution matters as much as compression. Most screens never display an image wider than about 1920 pixels, so capping the max width at 1920 for full-width images — or smaller for thumbnails — removes data the viewer would never see. Combine a sensible max dimension with WebP at around 80% quality and you will routinely turn multi-megabyte camera photos into files small enough to load instantly. Resizing keeps the aspect ratio by default, scaling proportionally so your images never look squashed.
Private and offline by design
Every step here runs on your own machine. The files you drop in are read into the browser, drawn onto an off-screen canvas, re-encoded, and offered back to you for download — nothing is transmitted over the network. That means the tool keeps working even with no internet connection, large batches stay private, and there is no queue, no account, and no upload progress bar to wait on. Add your images, tune the settings, and your compressed results are ready almost instantly.