JPG converter and compression
PNG, WebP and GIF are turned into JPG. A finished JPG can simply be compressed: choose the quality and the file gets lighter. The pixel size does not change. Everything happens in the browser, files are not uploaded anywhere.
JPEG, or JPG, is one of the most widespread raster image formats. The standard was developed by a joint group of photography experts and published in the early 1990s. The extensions jpg and jpeg denote the same format; the difference survives only because of limitations in old operating systems.
The format uses lossy compression based on the discrete cosine transform. The image is divided into blocks of 8 by 8 pixels, after which details that are less noticeable to the eye are simplified. The lower the chosen quality, the smaller the file and the more visible the typical artifacts along object edges.
JPG does not support transparency, so converting PNG, WebP or GIF files that contain transparent areas requires a background. On this page the background color is set manually, and white is used by default. Transparent pixels are replaced with the chosen color before the image is encoded.
The JPG converter suits photographs, screenshots with smooth gradients and any pictures that need to be sent or published quickly. The format is read by all browsers, viewers, messengers and websites. For graphics with sharp lines and text, it is better to save the image as PNG.
If the source file is already a JPG, the page works as a compressor: the image is re-encoded with a new quality value and the file size is compared with the original. Values from 60 to 80 usually give a noticeable saving with no visible distortion. The size in pixels stays the same.
All calculations are performed locally by the browser, and files are neither sent to a server nor stored. You can select several images at once and download the results one by one or with a single command. Names of finished files are generated randomly to avoid clashes when saving again.