Image Compressor

This tool uses lossy compression for JPG/JPEG images and a mix of lossy and lossless techniques for PNG and WEBP, depending on the source file. The core idea is that a raw image file stores far more color and detail information than the human eye can actually distinguish, so the compressor selectively discards the least visually important data first.

Why formats compress differently: JPG typically achieves the smallest file sizes because it's designed around lossy photographic compression from the start. PNG is a lossless format, so a PNG compressor can only shrink the file by optimizing how the existing pixel data is encoded (removing redundant metadata, choosing a more efficient color palette) — it can't discard detail the way JPG does, which is why PNG compression percentages are usually smaller than JPG's for the same photo. WEBP sits between the two: it supports both lossy and lossless modes and generally produces smaller files than JPG at equivalent visual quality, which is why you may notice WEBP output is smaller than the JPG version of the same upload.

Large, uncompressed images slow down page load times because every visitor's browser has to download the full file before it can render — and page speed is a measurable ranking factor in Google's search algorithm. Compressing images before upload is one of the few optimizations that improves both load time and visual outcome at the same time, rather than trading one for the other.

Blocky patches ("JPEG artifacts"): if you compress a JPG too aggressively, you'll start to see faint 8×8 pixel squares appear in smooth areas like skies or skin tones — a direct side effect of the block-based encoding JPG uses internally. This is usually the first visible sign a quality setting has gone too low.

Color banding: smooth gradients (sunsets, shadows) can start showing visible "steps" between colors instead of a smooth transition, once too much of the original color data has been discarded.

Re-compressing an already-compressed JPG tends to produce worse results than compressing a fresh, high-quality source once — each lossy compression pass discards more data, so artifacts compound. If you have access to the original, uncompressed version of a photo, compress from that rather than a version that's already been through a compressor once.