Almost every Indian application form, whether it is an SSC, IBPS or UPSC exam form, a scholarship portal, a PAN request or a passport-related upload, describes the photo it wants using some mix of three numbers: pixel dimensions, DPI and file size in KB. Candidates often treat these as one setting, which is why the same photo can be "too big" on one form and "too small" on another. This short guide explains what each number means, which ones a portal can actually measure, and the order in which to fix them so your upload goes through the first time.
Pixel dimensions are the width and height of the image, for example 200 × 230 pixels. A portal reads these directly from the file, so this is a hard check. Many bank and SSC-style forms list a fixed or near-fixed size, while UPSC-style forms usually give a range. If the number of pixels is wrong, the server usually shows a message like "invalid dimensions" or "image width should be between…".
Two things matter here. First, the ratio: a photo meant to be 3.5 cm × 4.5 cm is taller than it is wide, so a square selfie must be cropped, not squashed. Stretching a square image into a portrait shape distorts the face and can get the photo rejected later at document verification, even if the upload itself succeeded. Second, the amount of detail: blowing a tiny image up to a larger pixel size does not add detail, it only adds blur. If you are seeing this error, the PhotoFix page on fixing an invalid photo dimensions error walks through cropping to the right ratio before resizing.
DPI (dots per inch) only describes how large an image should print. A 600 × 600 pixel photo is the same image whether its file says 72 DPI or 300 DPI; only the printed size changes. That is why most online portals cannot really "see" quality through DPI. Some forms still mention a DPI value because their instructions were written for scanned paper photos, and a few upload checkers read the DPI field stored inside the JPEG.
If a form complains about DPI, the fix is usually to change the DPI tag in the file without touching the pixels, or to rescan at the requested setting if you are working from a printed photo. PhotoFix has a short explainer on what to do when a portal rejects your photo over DPI. What you should not do is upscale a small image just to reach a "300 DPI" number; that makes the file heavier and the face softer.
File size is how much space the JPEG takes, measured in kilobytes. It depends on pixel dimensions and on how strongly the JPEG is compressed. Indian portals commonly set both a minimum and a maximum, for example a photo between 20 KB and 50 KB and a signature between 10 KB and 20 KB on many SSC and banking forms, or a much wider band on other portals. Always read the current notification for your exam, because these limits change between cycles.
The minimum surprises people. A photo that is too small in KB often looks fine on a phone, but the server treats it as low quality and refuses it. The maximum is the usual problem with phone photos, which are often 2 to 5 MB straight from the camera. Getting a phone photo under 50 KB, or exactly into a 20 to 50 KB window, means reducing pixels first and then adjusting compression, not compressing a 4000-pixel image until it falls apart. If you prefer instructions in Hindi, there is a step-by-step guide on photo 20 KB kaise banaye.
Doing these steps out of order is the most common cause of blurry uploads. Compressing first and then resizing means the image is compressed twice, and each pass removes detail.
A signature image is checked for pixels and KB exactly like a photo, but it is much wider than it is tall and the KB limit is usually lower. Because a signature is mostly white space, it compresses very well, so many candidates hit the minimum KB limit rather than the maximum. Writing with a black pen on plain white paper, scanning or photographing in good light, and cropping tightly around the signature usually gives a clean result. Some exams also ask for more than one signature on the same sheet; the PhotoFix guide to the UPSC triple signature upload covers that format in detail.
| Error message you see | Which number is wrong | What to change |
|---|---|---|
| "Invalid dimensions" / "width should be…" | Pixels | Crop to the right ratio, then resize |
| "File size should be between X and Y KB" | KB | Adjust compression after resizing |
| "Image resolution / DPI not valid" | DPI tag | Change the DPI value, not the pixels |
| "File type not supported" | Format | Convert HEIC or PNG to JPG |
| Upload succeeds but photo is rejected later | Content | Check background, face size, glasses, lighting |
If the upload passes but your application is later flagged for an unclear signature, the problem is usually contrast or cropping rather than KB. Very light ink, a grey shadow from the phone, or a signature squeezed into too few pixels all make it hard to read. The article on what to try when a signature is rejected multiple times lists the fixes in order of how often they help.
You can do all of this with any photo editor, but it is easy to lose track of which step changes which number. PhotoFix is a free browser tool built for Indian forms: you pick the portal or enter the pixel and KB limits, and it crops, resizes, whitens the background and compresses in the right order, with processing done in your browser.