Image Compressor

Example Calculation

A phone photo is often 4 to 8 MB, and many forms and email services reject files over 2 to 5 MB. Choose the photo, leave quality on Balanced and the width on 2,000 px, and a typical 5 MB photo comes out near 0.5 MB with no visible difference on a screen. Use Smallest for a profile picture or a website thumbnail, and High if you plan to print.

Which settings to pick

How It Works

Press Choose files and select one or more pictures. Pick a quality, a largest width and an output format, then press Compress. Each picture gets a row that shows the size before and after, the percentage saved and a Download button.

Two things make a file smaller: lower quality and fewer pixels. Lowering quality removes detail your eye rarely notices, and reducing the width cuts the number of pixels, which has the bigger effect. A 4,000 pixel wide photo shown on a phone screen only needs about 1,200 pixels.

Keep the original format for most jobs. Choose WebP when the file will be used on a website or in a modern app, because it is usually smaller than JPG at the same quality. PNG files use lossless compression, so the quality setting does not change them, and reducing the width is what shrinks them.

Tips for better results

• Work on copies. The tool never changes your original files, but keeping the original means you can start again with different settings.
• Do a batch in one go. Select many pictures at once. Each one gets its own row and its own download button, so you can save only the ones you need.
• Check the result on the screen where it will be used. A picture that looks fine on a phone can look soft on a large monitor.
• Keep your device in mind. A very large batch of high-resolution photos can use a lot of memory on an older phone. If the page slows down, process the pictures in smaller groups.
• Private by design. The pictures are read and rewritten inside this page. That makes the tool suitable for ID photos, signed forms and other papers you would not want to send to a stranger's server.

Why compress a picture?

Many websites and email services limit attachments to a few megabytes, and a modern phone camera makes pictures that are larger than that. Smaller pictures upload faster, use less mobile data and load more quickly on a web page. Compressing with sensible settings keeps a picture that still looks the same at normal size.

Formula Explained

Each picture is drawn on a canvas at the new size and saved again with your browser’s encoder: JPEG and WebP use the quality value you choose (0.5 to 0.9), and PNG is lossless.

new width = min(original width, largest width) and percent saved = (1 − new size ÷ old size) × 100.

Assumptions and limits

• Everything runs on your device. The page makes no network request with your images.
• Your browser decodes and re-encodes the pictures, so results can differ a little between Chrome, Safari and Firefox.
• Transparent areas turn white when the result is a JPG. Photo metadata such as location is not copied to the new file.