You've filled in the whole form. Name, address, qualifications, everything. Then the upload page says your signature must be 140 x 60 pixels and between 10 and 20 KB, and suddenly the easy part isn't easy anymore. Sound familiar? It happens to almost everyone applying online.
Bank exams like IBPS and SBI ask for this, and so do SSC and a lot of state government recruitment forms. Some passport and visa portals want a signature image too, along with university admissions, scholarship applications and even certain bank KYC updates. Each one has its own size rules, so always read the notice first. A signature resize done wrong usually means a rejected upload, or worse, a blurry signature on an application you can't edit later.
Start with a clean original
Most quality problems start here, not during resizing. Sign on plain white paper with a black or dark blue pen, a gel pen works nicely. Then scan it, or take a photo in daylight with the phone held flat above the page. No shadows. No lined paper. Crop tight around the signature so there's only a little white space left on each side.
Resizing it properly
Now the actual signature resize tool required here. Keep the aspect ratio locked so your signature doesn't get squashed or stretched, since most tools have a small lock icon or a "maintain proportions" box for this. Go from big to small, never the other way. Blowing up a tiny image always turns it fuzzy, no matter what software you use.
File size is a separate thing from pixel size, by the way, and people mix them up constantly. If the dimensions are right but the file is 45 KB and the limit is 20 KB, lower the JPEG quality slightly instead of shrinking the image further. Converting to black and white helps too. A signature doesn't need colour, and dropping it cuts the file size a lot.
Before you hit upload
Open the final file and zoom in to 100%. Can you read it clearly? Are the edges smooth, not blocky? Check the format as well, because most portals want JPG or JPEG and will reject PNG straight away. And keep your original scan saved somewhere safe. Next form will probably want a different size, and starting again from a high-quality copy beats resizing an already-resized file.
A proper signature resize takes five minutes once you know the steps. Much better than finding out after the deadline.