What Determines an Image's File Size?
When you take a photo on your phone or camera, the file size is determined by three main factors: pixel dimensions (width ร height), color depth, and the file format. Modern smartphone cameras capture at high resolutions (4000 ร 3000 px), creating heavy 5MB to 15MB files with millions of raw details.
For job applications, exam portals, and web pages, full-resolution files are unnecessary. Modern browser-based compression groups imperceptible color variations together, reducing file weight by 70% to 85% while keeping the picture sharp.
Exam portals (UPSC, SSC, NEET, JEE, and state boards) receive millions of applications. To guarantee server stability, they require candidate photos strictly between 20 KB and 50 KB, and signature scans under 20 KB.