Compress PNG Online

With PNG output, the default, the tool reduces each image to a palette of at most 256 colors using median-cut quantization, maps every pixel to its nearest palette color and writes an indexed PNG. Transparency is kept in the palette, so cutouts and soft edges survive. The new file is written from the pixels alone, so camera metadata is not carried over. On flat graphics such as logos the change is hard to see, while the file usually becomes much smaller. Everything runs in your browser, with nothing to install.

JPEG has no transparency, so logos, watermarks and cutouts saved as JPEG gain a solid background. PNG keeps the transparent areas and gives crisp edges on text and graphics, but a full-color PNG export can be very large. Compressing it to a color palette keeps the transparency and sharp edges in a much smaller file that will not slow down your portfolio website or client galleries. For ordinary photographs with no transparency, JPEG or WebP is usually the better choice, and this tool can produce those too from the Output Format buttons.

Drag several images onto the area labeled Drag & Drop or Click to Upload, or click it and select them together. You can keep adding files, and each appears in the list with its size and a Ready status. Choose PNG, JPG or WEBP under Output Format, set Image Quality with the slider and press Convert & Download. The files are processed one after another and each downloads on its own, named converted_ followed by the original name. There is no ZIP file. Clear All empties the list.

Lossless PNG compression rewrites the file's data more efficiently and keeps every pixel identical, but the saving is usually modest on photographic content. Lossy PNG compression, which this tool uses for PNG output, reduces the image to a limited palette of at most 256 colors and stores it as an indexed PNG. Similar colors are merged, so some subtle tonal steps are lost, but the file can shrink considerably. It works best on graphics with flat areas of color and is less suited to smooth photographic gradients.

The best time to compress your PNG files is at the very end of your editing workflow, right before you publish the images on a website, send them to a client or place them in a digital publication. Do all your heavy editing, color grading and retouching on your original files or working formats like PSD or TIFF. Once the image is finalized and exported as a high-resolution PNG, run it through the compression tool. Compressing at the final stage ensures you do not compound data loss by repeatedly editing and saving a compressed file.

Nothing is uploaded, so your internet connection plays no part. The work happens on your own device: the tool reads every pixel, builds a palette from the image's colors and matches each pixel to it before writing the new file. A very large, high-resolution image has many millions of pixels, so it takes longer, and a slower computer or phone adds time. Files in the list are processed one at a time, and each status shows Converting until its download is ready.

With PNG selected as the output format, no. The palette stores a transparency level for each color, so fully transparent backgrounds stay transparent and soft, partly transparent edges are kept as well. WEBP output also keeps transparency. Only JPG drops it, because the format has no alpha channel, so transparent areas are filled with white. For watermarks, logos and isolated subjects that need a clear background, leave the output on PNG, which is the default.

The pixel dimensions never change, so true pixelation is unlikely, but color banding can appear when a palette of at most 256 colors has to describe a smooth gradient such as a clear sky or soft studio light. Move the Image Quality slider higher, because the slider sets the palette size and 100 percent allows the full 256 colors. If banding remains and the image needs no transparency, choose JPG or WEBP instead, which handle smooth photographic tones better.

Your images are processed entirely within your web browser, on your own device, and only to produce the compressed copies you download. They never leave your device, so nothing can be shared with third parties or used to train machine learning models. The originals on your computer stay untouched, because the tool writes new files rather than changing the ones you selected. The tool is free and adds no watermark; you only need a free Imagen account, created once after confirming you are a photographer.

The tool sets no fixed limit on file size or on the number of images. The practical limit is your device's memory, because each image is decoded in full in the browser. Very large files or long lists may run slowly on an older computer or phone, and a browser may struggle with extremely large images. If that happens, process the files in smaller groups. Some browsers also ask for permission the first time a page downloads several files in a row, so allow it to receive every result.