AFCAT Photo and Signature Size
The photo and signature specification for the Air Force Common Admission Test application form, with a tool preset to match it.
Finding the best quality that fits…
- Original
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- Result
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- Reduction
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- Dimensions
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This tool is preset to bring your photograph under 100 KB, the AFCAT limit.
How to use this tool
- Choose your image, drag it onto the box, or paste it from the clipboard. JPG, PNG, WebP and HEIC all go in; JPEG comes out.
- There is nothing to set. This page is already fixed at under 100.0 KB, JPEG.
- It scales the image down first — on our reference file, to 1131 × 1508 px — then searches the encoder quality. That run took 7 encodes.
- Download from the panel, which shows the original size, the final size and the output dimensions. Nothing was uploaded at any point.
AFCAT also requires a thumb impression upload in most cycles.
AFCAT Photo and Signature Size — the specification
| Photograph | JPEG |
|---|---|
| Signature | JPEG |
| Format | JPG / JPEG |
| Official source | afcat.cdac.in |
AFCAT Photo and Signature Size: why uploads get rejected
Landing under 100 KB is necessary but not sufficient. These are the reasons a file that meets the size still gets sent back:
- The upload is a PNG. The AFCAT portal reads the file header, not the extension, so renaming photo.png to photo.jpg changes nothing — it is refused before the 100 KB limit is even considered. Re-encode it as real JPEG.
- The photograph is over 100 KB. Compress to just under the limit rather than as small as possible — an over-compressed face can be refused as unclear.
- The signature does not meet JPEG. It is a separate upload from the photograph with its own limit, and it is the one most often overlooked.
- The signature was photographed rather than scanned, so white paper came out grey and the 30 KB limit forced the quality down further. Sign in black or dark blue on plain white paper, shoot in daylight with no shadow across the page, and crop tightly to the strokes before resizing — a signature floating in half a sheet of paper ends up a few pixels tall once it is fitted to the box.
How it works
Hitting a size limit exactly is a search problem, not a setting. There is no quality value that means “100.0 KB” — how many bytes a given quality produces depends entirely on the picture. So this tool encodes, measures the real file, and adjusts.
It starts by capping the pixel count, because quality alone cannot rescue an image that is simply too large. On the reference file measured below that meant going from 3024 × 4032 to 1131 × 1508 before the first encode. That ordering is what keeps the search cheap: the six or seven encodes that follow all work on the smaller image.
It then binary-searches the quality parameter: encode, measure, halve the remaining range, repeat. The run below took 7 encodes to land at 99.3 KB. A tool that picks one fixed quality instead either overshoots the limit or comes in far under it and throws away detail you did not need to lose.
Every one of those encodes ran on your own device through the browser’s canvas API — including the intermediate attempts the search threw away. None of them was uploaded.
A measured run of this exact preset
Not an estimate: this page’s own code, run against a 12.2 MP photograph and an A4 scan at 200 dpi, with every encode recorded. The files and the method are published here.
| Input | Result | Change | Outcome |
|---|---|---|---|
| 12.2 MP photograph 3024 × 4032 px · 2.94 MB | 99.3 KB 1131 × 1508 px | 97% smaller | Under the 100 KB limit |
| A4 scan at 200 dpi 1654 × 2339 px · 996.0 KB | 99.8 KB 1099 × 1554 px | 90% smaller | Under the 100 KB limit |
Step by step
Before touching quality at all, the tool worked out how many pixels 100.0 KB can realistically describe, and scaled the image from 3024 × 4032 down to 1131 × 1508 — 86% fewer pixels. Doing this first is what keeps the run quick: every attempt after it encodes the smaller image rather than the original.
The first probe at quality 0.96 came out at 522.2 KB, about 5.2× the 100.0 KB limit, so the search began.
It then narrowed the quality setting 6 times — quality 0.51 gave 91.4 KB, quality 0.73 gave 152.8 KB, quality 0.62 gave 113.6 KB, quality 0.57 gave 103.7 KB, and so on — settling on quality 0.55.
Final file: 99.3 KB, using 99.3% of the allowance, with 768 B to spare.
Who needs AFCAT Photo and Signature Size
Candidates filling the Air Force Common Admission Test form, usually close to the deadline when the afcat.cdac.in portal is slowest. Having the photograph and signature ready in the right format and inside the 100 KB limit removes the most common reason a submission fails at the final step.
AFCAT Photo and Signature Size — frequently asked questions
What photo size does AFCAT require?
The photograph must be JPEG. The tool on this page is preset to that specification.
What signature size does AFCAT require?
The signature must be JPEG. Sign on white paper in dark ink, scan or photograph it in good light, then crop tightly before resizing.
My AFCAT upload is under the maximum but still rejected. Why?
Check the format and the dimensions before the size. AFCAT caps the photograph at 100 KB, but a file that meets that and is still refused is usually a PNG renamed to .jpg, or the wrong shape. Portals read the real file header, so renaming an extension changes nothing.
Can I use the same photo for other exams?
Usually yes, provided the photograph is recent and the other exam’s dimension and size rules are met. Requirements differ between commissions, so check each specification rather than assuming.
Are these specifications current?
We could not verify every figure here against a current official notification, which is why the warning appears at the top of this page. Confirm before you upload. Commissions do revise requirements between cycles, so always confirm against the official notification for the exam you are applying to.
How do I resize my photo for the AFCAT form online?
Upload it to the tool at the top of this page. It is already set to the AFCAT specification, so there is nothing to configure — select your photo and download the result. Everything happens on your device, so it works even on a slow connection near the application deadline.
Related tools
From other categories
Background reading: Photo and Signature Sizes for Every Major Indian Exam
Your photograph is never uploaded. That matters near a deadline: the work happens on your device, so it does not slow down when the portal does, and it works on a weak connection — how that works.
Disclaimer. The AFCAT Photo and Signature Size specification above is taken from afcat.cdac.in and was last checked on 2026-08-30. Requirements change between cycles — confirm against the official notification before you submit. Full disclaimer.