Compress PNG, JPEG and WebP in bulk. Every result is checked against the original, so you get the smallest file that still looks the same. Runs in your browser.
Drop PNG, JPEG or WebP images
Batch friendly. Each image is checked against the original, so you get the smallest file that still looks the same. Nothing is uploaded.
How it decides
For each image the compressor tries lossless PNG optimisation, a 256-colour palette with error-diffusion dithering, and, for opaque images, MozJPEG. With WebP selected it tries WebP too. It decodes each result again, compares it with the original, and keeps the smallest one that passes your quality guard. The fidelity column shows the score in decibels: 40 dB or more can't be told apart by eye, and around 36 dB only shows when zoomed in.
Good to know for app assets
Smaller files speed up downloads and shrink your app bundle, but RAM use depends on pixel dimensions. Ship @2x/@3x or xhdpi–xxxhdpi sizes instead of one huge image.
Android's build can crunch PNGs again. If your compressed files grow during the build, set isCrunchPngs = false for release builds.
Images inside a Lottie file? Use the Lottie Compressor. It does this for every embedded image and leaves the animation alone.
Questions
Is this lossless?
In Lossless mode, yes: pixels stay identical and only the PNG encoding is optimised. Smart mode can reduce colours or switch to JPEG, but only when the result passes the quality guard compared with the original.
Is it like TinyPNG?
Similar idea: palette reduction with dithering. The difference is that every result is measured against the original and rejected if it falls below your quality guard. Files never leave your browser, and there are no daily limits.
Which format should I use for apps?
PNG for UI art with transparency, JPEG for opaque photos, WebP when every target supports it (Android 4.2.1+, iOS 14+, all modern browsers). "Best for each image" picks the smallest that passes the guard.
Is there a file size limit?
No fixed limit, since it runs on your device. Very large images (over about 40 megapixels) can run out of browser memory on phones.
Does it strip metadata?
Yes. Re-encoded files drop EXIF and other metadata, including GPS location in photos.