How to use the Image Compressor
Add your images
Drop in one file or a batch. They are read by your browser directly and never transmitted.
Set dimensions and quality
Resize to the largest size the image will actually be displayed at, then adjust quality until the artefacts become visible and step back one notch.
Download the result
Save the compressed file, or convert to WebP on the way out for a further reduction at the same visual quality.
Resizing matters more than compressing
The biggest single win is almost always dimensions, not quality settings. A photograph straight from a phone is around 4000 pixels wide. Displayed in a 600-pixel column, more than 90% of that data is decoded and thrown away by the browser on every single page load.
Resize to roughly the largest size the image will ever be displayed at - double it if you are supporting high-density screens - and file size falls dramatically before you touch the quality slider at all.
Choosing a format
WebP is the sensible default for the web now. It is supported by every current browser and typically produces files 25 to 35% smaller than an equivalent JPEG, with transparency support that JPEG lacks entirely.
JPEG remains the safe choice for photographs going somewhere with unknown support, and for anything a recipient might open in older desktop software. PNG should be reserved for images that genuinely need lossless quality or sharp-edged transparency - screenshots, logos, diagrams. A photograph saved as PNG is usually several times larger than it needs to be, which is the most common avoidable mistake in this area.
Why in-browser compression is the private option
Most online image compressors upload your file to a server, process it there, and hand back a download. Whatever their policy says, the image was on someone else infrastructure - a poor arrangement for a passport scan, a medical document, an unreleased product photograph or a screenshot containing customer data.
This runs on the canvas and codecs already in your browser. The file is read locally, processed locally, and saved locally. It also means there is no upload wait and no file size cap imposed by a server.
Frequently asked questions
- Are my images uploaded to a server?
- No. Everything runs in your browser using its built-in image codecs. Files are never transmitted, which makes this safe for sensitive documents and unreleased material.
- Should I use WebP or JPEG?
- WebP for the web - it is universally supported now and typically 25 to 35% smaller at the same quality. JPEG when the file is going somewhere with unknown or older software support.
- What quality setting should I use?
- Around 75 to 85 for photographs is usually indistinguishable from the original. Reduce until artefacts become visible, then step back one notch.
- Will compressing damage my original file?
- No. Your original is untouched; a new compressed file is produced for you to download.
- Is there a file size limit?
- No server limit, because nothing is uploaded. Very large images are bounded only by your browser available memory.