What size are the photograph and signature fields usually capped at?

Photograph and signature fields commonly sit in the 20 to 50 KB band, and document or certificate fields in the 100 to 500 KB band. These are the bands the forms tend to fall in, not a rule — every body publishes its own figures and changes them between recruitment cycles, so the form in front of you is the authority.

The form says 20 KB but my file is 20.2 KB. Will it pass?

Almost certainly not. These checks are exact and unforgiving, and there is no rounding in your favour. Aim comfortably under the cap rather than at it: a 20 KB field is best met with a file in the high teens.

Why does the portal reject my file when the size is correct?

The commonest causes are a file whose extension does not match its actual contents, a picture whose pixel dimensions are outside the stated range, and a kilobyte counted as 1,000 bytes where the portal counts 1,024. Renaming a HEIC from an iPhone to .jpg does not make it a JPEG, and most validators check the bytes rather than the name.

Should I compress before or after cropping the picture?

After. Any change to the picture itself — a crop, a rotation, a change of dimensions — makes the file be written again, and the new file has a new size. Compression is always the last step before upload.

The form wants a JPG and my phone produced a HEIC. What now?

The picture has to be written out as a JPG by something before the form will take it. On an iPhone, Settings, Camera, Formats, Most Compatible makes the camera record JPG from then on; an existing photograph can be shared to Files and saved as a JPEG. Renaming the file is not enough.

Guide

Upload limits on Indian exam portals

A recruitment or university form does not ask you to make the picture look right. It asks for a file under a number of kilobytes, often inside a range of pixel dimensions, and it refuses anything else without explaining which rule you broke.

That is why the queries arrive with the number already in them. Nobody wants to compress an image in the abstract; they want a file that a form will accept, and the form has told them the figure it will accept it at. This page is about what those figures are measuring and how to satisfy two of them at once.

The three fields, and what each one measures

The photograph

A recent passport-style photograph, usually with a stated pixel range and a byte cap in the 20 to 50 KB band. The byte cap is the binding constraint: at those dimensions a photograph has plenty of detail to give up, and a quality setting in the middle of the scale will usually get there without the picture looking obviously degraded on a form.

The signature

A scan or a photograph of a signature on white paper, usually capped tighter than the photograph. It is also the easiest field to satisfy, because a signature is a few dark strokes on a flat background and there is very little information in it. Trim the scan down to the signature itself before anything else — most of the file is usually paper.

The document

Certificates, mark sheets and identity documents, usually in the 100 to 500 KB band. These are the ones where legibility matters and where compressing too far is a real risk: a mark sheet whose numbers cannot be read is a rejected application, and it will be rejected by a person rather than by a validator.

These bands are a starting point, not a specification.

No figure on this page was taken from a published rule that applies to every body. Caps differ per organisation and change between cycles, and a page that quoted exact numbers would be quietly wrong within a year. Read the form in front of you and treat the bands here as an indication of what to expect.

Why a form rejects a file that looks correct

The kilobyte is counted differently. A form checking against 1,024 bytes to the kilobyte will refuse a file you measured at 1,000. Aim under the cap rather than at it.
The extension does not match the bytes. A HEIC from an iPhone renamed to .jpg is still a HEIC, and validators generally read the first few bytes rather than the name.
The pixel dimensions are outside the stated range. Some forms state the range only in the instructions page, not beside the field.
The picture is rotated. A photograph taken on a phone carries an orientation flag, and a server that ignores it displays the picture on its side even though it looked upright on your computer.
The upload silently reused a cached file. Where a form shows a preview after upload, look at it; that is the only view of what the server actually received.

The order of operations, when both are capped

This is the part that goes wrong most often, and it is a matter of sequence rather than tools. Bytes are a property of the file. Dimensions are a property of the picture inside it. Change the picture and the file gets written again — with a new size, which is very often back over the cap you had just met.

1Write down both numbers before you touch the file. The pixel dimensions and the byte cap are usually in different places on the form — one in the instructions, one beside the field. Copy both out before you start, along with the file type the form asks for.
2Set the pixel dimensions first. Dimensions are a property of the picture; bytes are a property of the file that holds it. Changing the picture forces the file to be written again, which changes its size. Do the pixels first, in whatever tool you use for that, and do not come back to them.
3Bring the bytes down second. With the dimensions settled, put the file through a byte cap and let a search find the largest version that fits underneath it. Nothing at this stage should change the width or the height.
4Check the size on disk, not in a preview. The number the form checks is the size of the file in your folder. Right-click, look at the properties, and compare it with the cap you wrote down. If the form counts a kilobyte as 1,024 bytes and you counted 1,000, a file at 20.4 KB will be refused.
5Upload, then look at what the portal shows you. Most portals redisplay the photograph after upload. If what comes back is rotated, cropped or blank, the file reached the server but the server read it differently from your computer — re-export it as a plain baseline JPG and try again.

Done in that order, each step leaves the previous one intact. Done in the other order, the last step undoes the one before it, which is why so many people find themselves compressing the same photograph four times.

What this page cannot tell you

It cannot tell you the cap on your form. There is no central register of these figures, they are set per body and per cycle, and the only reliable source is the instruction sheet attached to the application you are filling in. What this page can do is explain what the figure is measuring, so that when the form says 50 KB you know exactly which number on your computer to compare it with.

Asked about upload fields

What size are the photograph and signature fields usually capped at?: Photograph and signature fields commonly sit in the 20 to 50 KB band, and document or certificate fields in the 100 to 500 KB band. These are the bands the forms tend to fall in, not a rule — every body publishes its own figures and changes them between recruitment cycles, so the form in front of you is the authority.
The form says 20 KB but my file is 20.2 KB. Will it pass?: Almost certainly not. These checks are exact and unforgiving, and there is no rounding in your favour. Aim comfortably under the cap rather than at it: a 20 KB field is best met with a file in the high teens.
Why does the portal reject my file when the size is correct?: The commonest causes are a file whose extension does not match its actual contents, a picture whose pixel dimensions are outside the stated range, and a kilobyte counted as 1,000 bytes where the portal counts 1,024. Renaming a HEIC from an iPhone to .jpg does not make it a JPEG, and most validators check the bytes rather than the name.
Should I compress before or after cropping the picture?: After. Any change to the picture itself — a crop, a rotation, a change of dimensions — makes the file be written again, and the new file has a new size. Compression is always the last step before upload.
The form wants a JPG and my phone produced a HEIC. What now?: The picture has to be written out as a JPG by something before the form will take it. On an iPhone, Settings, Camera, Formats, Most Compatible makes the camera record JPG from then on; an existing photograph can be shared to Files and saved as a JPEG. Renaming the file is not enough.

Related work

Compress to a size in KBType the cap from the form and let the search find the largest file that fits under it.
Why this JPEG will not get smallerWhat to do when the cap is still out of reach after the quality is at its floor.
Compress a JPEGThe quality scale itself, if you would rather set it than let a search find it.