Image Compressor

What this compressor does

It re-encodes your photos at a lower quality, and optionally at a smaller pixel width, so the files are lighter to email, upload or put on a web page. You choose the quality with a slider and see the new size next to the original for every image, then download the ones you want.

Private by design

Everything happens in your browser using the same image tools your browser uses to show pictures. The files are not sent to a server, so there is no upload wait, no file limit imposed by a service, and nothing for anyone else to see. Closing the tab discards the results.

Choosing quality, format and width

For photos, a quality of 70 to 80 usually looks the same as the original to the eye while cutting the file by half or more. Below about 50, blocky patches start to show. JPEG works everywhere. WebP is usually smaller at the same look and is supported by all current browsers. Reducing the width helps most: a phone photo is often 4000 pixels wide, while a web page rarely shows it wider than 1600.

PNG files are lossless, so the quality slider does not change them, and re-saving as PNG can make a photo larger. For photos, switch the output to JPEG or WebP. Transparent areas turn white in JPEG, so keep PNG or use WebP for logos with see-through backgrounds. To read a compressed image back as text, you can try the Base64 Studio.

Good to know

Compressing is a one-way trade, so keep your originals. Photo metadata such as camera details and location is removed in the process, which is also handy for privacy. If the result is not smaller than the original, the tool tells you, because an already optimized image cannot always be reduced further. Animated GIFs and SVG files are not supported here.

Frequently asked

Are my images uploaded to a server?

No. They are compressed by your browser on your own device. Nothing is sent to Curious Assistant or anywhere else.

What quality setting should I use?

For photos, 70 to 80 is a good starting point, as it usually looks identical while saving a lot of space. Try lower values for thumbnails and higher ones if you will print or edit the image later.

Why did my PNG get bigger?

PNG is lossless, so the quality slider has no effect on it, and re-encoding a photo as PNG can increase the size. Convert photos to JPEG or WebP instead. Keep PNG for graphics with sharp edges or transparency.

Is anything removed from the image?

Yes. Metadata such as camera model, date and GPS location is not kept, because the picture is redrawn and saved fresh. Colour profiles are also dropped, so colours may shift slightly in rare cases.

Can I compress many images at once?

Yes. Choose several files at once and each one is processed with the same settings. Download them one by one from the results list.