To resize a JPEG image without losing quality, use software like Adobe Photoshop or GIMP, ensuring you select lossless resizing options. Opt for bicubic interpolation for better quality preservation and avoid upscaling the image. Resize gradually in small increments to minimize data loss.
Save the resized image in the same JPEG format to prevent further compression. Preview the image at 100% zoom before finalizing to ensure quality meets expectations. With these steps, you can maintain the image's quality throughout the resizing process.