Trims your scan, frames it so the signature fills GATE's 70–80% — a range with a ceiling, not a minimum — and lands inside its 2.75–3.75 aspect, 250×80–580×180 pixel and 3–300 KB limits. Calibrated on GATE's own fourteen published sample signatures.
or browse your files
| Format | JPEG / JPG |
|---|---|
| File size | 3 KB – 300 KB |
| Resolution | minimum 250 × 80, maximum 580 × 180 pixels |
| Aspect ratio | height : width of 1 : R, R between 2.75 and 3.75 |
| Signature coverage | 70–80% of the image — a range, not a minimum |
| Ink | Black or dark blue only |
| Signed by | The applicant, and nobody else |
The signature you upload is checked against the one you write at the examination centre. GATE states that if they do not match, the applicant could be disqualified — so this is not only an upload formality.
It means the bounding box of your writing, not the ink.
The ink reading is arithmetically impossible. We measured GATE's four published acceptable signatures pixel by pixel: the strokes themselves cover 3.1%, 5.4%, 7.4% and 8.3% of their frames. A signature is a handful of thin lines; nothing written by hand approaches 70% ink. Read instead as the rectangle enclosing the writing, the rule is an ordinary margin instruction — at 75% coverage you leave roughly a tenth of the width and a tenth of the height as white space on every side.
Load GATE's four acceptable samples into any measuring tool and the writing covers 31% to 55% of the rectangle drawn around it. That looks like a direct contradiction of the 70–80% rule. It is not, and the reason matters for how you crop.
That rectangle is about 4.8 times wider than it is tall. GATE's own aspect limit is 3.75. The drawn box therefore cannot be a compliant upload under GATE's own specification — it is the signature box on the paper you sign, which is why two rejected samples are captioned as ink falling “outside the signature box area”. The 70–80% rule applies to the image you crop out of that box, not to the box itself.
Two rules have to hold at once. The frame must be 2.75–3.75× wider than tall, and your writing must fill 70–80% of it. Write the frame as W×H and the writing's bounding box as w×h. The writing has to fit, so W ≥ w and H ≥ h, and coverage is wh/WH. Working that through, coverage can only reach 70% if
1.93 ≤ w/h ≤ 5.36
— that is, your signature's own bounding box must itself be between roughly 1.9 and 5.4 times wider than it is tall. Outside that band no crop exists that satisfies both rules, and the tool will say so rather than hand you a file that fails at scrutiny.
This is not a theoretical case. GATE rejects one of its own samples for being signed at an angle: tilting the writing pushes its bounding box towards square, and at a bounding box below 1.9 the geometry closes. A signature stacked onto two lines does the same thing. A single very long, very flat flourish fails at the other end.
Measured automatically:
Not measurable, and yours to confirm:
Same application, different file. Each has its own limits — they are not interchangeable.
JPEG or JPG between 3 KB and 300 KB, with a resolution between 250 x 80 and 580 x 180 pixels. The aspect ratio is given as height to width of 1 to R, where R can be between 2.75 and 3.75, so the image is between 2.75 and 3.75 times wider than it is tall. The signature itself must cover 70 to 80 percent of that image, in black or dark blue ink only.
The area the signature occupies - its bounding box. It cannot mean ink pixels. We measured GATE's four published acceptable signatures and the ink itself covers only 3 to 9 percent of the frame by pixel count, because a signature is a few thin strokes. No signature on earth reaches 70 percent by ink. Read as the box that encloses the writing, 70 to 80 percent is an ordinary margin instruction: leave roughly a tenth of the width and a tenth of the height as white space on each side.
Because the rectangle drawn in those samples is the signature box on paper, not the image you upload. That box is about 4.8 times wider than it is tall, which is outside GATE's own permitted range of 2.75 to 3.75, so it cannot be a compliant upload. Measured against their drawn box, the four acceptable samples cover 31 to 55 percent. The 70 to 80 percent rule applies to the crop you produce from the box, not to the box.
Yes. Like GATE's 60 to 70 percent face rule for photographs, this is a range and not a minimum. A signature cropped hard against the edges exceeds 80 percent and is as wrong as one lost in white space. Two of GATE's rejected samples are rejected for ink running outside the signature box.
Because of its shape. The frame must be 2.75 to 3.75 times wider than it is tall, and the signature must fill 70 to 80 percent of it, and those two rules together only work if your signature's own bounding box is between about 1.9 and 5.4 times wider than it is tall. A signature written at a steep angle, stacked on two lines, or drawn as one very long thin stroke falls outside that and no crop can fix it. GATE rejects one of its own samples for exactly this - signed at an angle, so its bounding box is nearly square.
Black or dark blue only. GATE rejects two of its published samples for ink in other colours. The tool measures the colour of your strokes and tells you if they read as green, red or any other hue, and if they are too faint to be legible - another of GATE's rejections is a signature that is simply too washed out to see.
No, and neither can any other tool. GATE rejects signatures written in ALL CAPITALS and signatures reduced to initials, but those are judgements about handwriting, not measurements. The tool checks everything that can be measured - geometry, coverage, colour, contrast, background, file size - and lists the rest as a short checklist for you to confirm yourself.
No. The trim, the coverage measurement, the colour check and the compression all run in your browser on your own device. Your signature image is never transmitted.
Specifications on this page are taken from the Photograph and Signature page published by IIT Guwahati for GATE 2026, and are calibrated against the sixteen sample photographs and fourteen sample signatures published on that same page. GATE 2027 is organised by IIT Madras and carries the same figures on its own Photograph and Signature page.
GATE rotates organising institutes each year and its specifications have changed between cycles, so check the brochure for the year you are applying in. We are not affiliated with the GATE organising institute.