Where the 50 KB limit appears
Job portals, college admission sites and bank or government forms often allow photos and small scans up to 50 KB. That is enough for a clear passport-style photo, but a normal phone photo is still many times larger.
What happens when you resize
Each picture is saved as a JPG with the highest quality that still fits under 50 KB. If the website asks for exact dimensions, type the width and height in pixels; otherwise the original shape is kept and the pixel size is reduced only if needed. You can resize several pictures at once, and each is fitted under 50 KB separately.
What changes and what does not
The picture is not cropped — only its file size and, when necessary, its pixel size change. Transparent PNG pictures get a white background, because JPG does not support transparency. The result is a JPG, which almost every portal accepts.
Common problems and how to fix them
The portal says the dimensions are wrong: enter the exact width and height from the instructions. The photo looks soft: crop to the head and shoulders first so fewer pixels are needed. The portal wants under 20 KB instead: use Resize Image to 20KB.
Good habits
Use a recent photo with a plain light background, crop before resizing, and keep the full-size original for future applications.