About CompressLocal

CompressLocal is a free image compression tool that runs in your browser. No sign-up is needed, and the tool does not upload selected file bytes to a processing server. Pick a target size, select your images, and download the locally generated versions.

Why we built this

Most image compressors upload your files to a remote server. That means your photos, screenshots, and documents pass through someone else's infrastructure. We wanted a tool that gives you the same results without the privacy trade-off.

Whether you're compressing sensitive screenshots at work, preparing photos for a client, or optimizing images for your blog, reducing unnecessary file transfers matters. CompressLocal's tools do not upload selected image bytes to a processing server. The page still loads the separate services disclosed in the Privacy Policy.

How it works

Under the hood, CompressLocal uses the browser's built-in Canvas API and Web Workers to re-encode images at progressively lower quality levels until they fit under your target size. Two images process concurrently to balance speed and memory. The entire process runs in background threads so the UI stays responsive.

For PNG files, which are lossless and don't respond to quality-based compression, the tool internally converts them to WebP format to achieve meaningful size reduction. The output is visibly identified and saved with a .webp extension so its name, reported type, and encoded bytes agree.

Supported formats

• JPEG — Quality-based compression, great for photographs and complex images with gradients
• PNG — Internally converted to WebP for effective compression and saved with a truthful .webp extension
• WebP — Modern format with excellent compression ratios, supported by all major browsers since 2020

More than just compression

CompressLocal also includes free image tools whose selected-file processing runs in your browser:

• Format converter — Switch between JPG, PNG, and WebP with adjustable quality
• Image resizer — Resize by width, exact dimensions, or percentage with aspect ratio lock
• Image to PDF — Merge multiple images into a single PDF with reordering and page size options

Tech stack

Built with Next.js, Tailwind CSS, and the browser-image-compression library. Deployed as a fully static site on AWS CloudFront. There are zero API routes and zero server-side processing — the entire site is just HTML, CSS, and JavaScript served from a CDN.

Privacy by design

The production architecture is a static site served from a CDN. Tool workflows use browser APIs and have no CompressLocal processing API endpoint, so application code does not send selected file bytes to a processing server. Hosting, consent, analytics, and advertising requests remain separate and are disclosed in the Privacy Policy.

You can inspect this boundary in DevTools: filter the Network tab while processing and verify that disclosed page-service requests do not contain the selected image bytes.

Common use cases