Image Compressor

What image compression does

Image compression reduces a file's size by simplifying the data used to store it — either by allowing a small, usually imperceptible loss in quality (lossy compression, used by JPG and WebP) or by re-encoding the file more efficiently without discarding any visual information (lossless compression, closer to how PNG works). This tool is built to run that process locally in your browser using WebAssembly, so photos never need to be uploaded to a server just to get smaller.

A quality slider lets you control the trade-off directly: push it toward maximum compression for the smallest possible file, or keep it closer to the original for minimal visible difference. The right setting depends entirely on what the image is for — a quick web thumbnail can tolerate more compression than a print-quality photo.

Why smaller images matter

On the web, image weight is one of the biggest factors in page load speed, which directly affects both user experience and search rankings — Google's Core Web Vitals explicitly measure how quickly the largest visible element on a page loads, and that element is very often an image. Beyond the web, smaller image files upload faster to slow connections, take up less phone storage, and fit more easily under email attachment or form upload limits.

Common use cases

Website owners and bloggers compress images before uploading them to keep page load times fast. Online sellers compress product photos so listings load quickly on marketplaces with strict image size limits. People compress phone photos before emailing them or uploading them to a slow-loading form, and social media managers compress images to fit platform-specific size recommendations without a visible quality drop.

Tips for compressing without losing quality

For photos, a moderate compression setting (roughly 70–85% quality in JPG terms) is usually visually indistinguishable from the original while cutting file size substantially — pushing much lower starts to introduce visible blockiness, especially in areas with smooth gradients like skies. If the image contains text, logos, or sharp edges, compress conservatively or consider a lossless format, since compression artifacts are most noticeable around hard lines and fine detail.

How this compressor protects your privacy

Photos frequently carry more than just pixels — phone cameras often embed EXIF metadata that can include the date, time, camera model, and sometimes GPS coordinates of where a photo was taken. Because compression here runs locally using WebAssembly rather than on a remote server, your original image and any metadata attached to it never leave your device during the compression process, unlike many online compressors that require a full upload before they can do anything. That's a meaningful difference if you're compressing personal photos rather than stock or already-public images, and it means there's no waiting on an upload or download queue either — the compressed file is ready as soon as your device finishes processing it, typically within a second or two even for a large photo, with no upload progress bar to sit through first.