What CAT asks for
CAT's rules for both uploads are one paragraph in section 1.3 of the Registration Guide. Both sizes are upper limits ("within the dimensions of"), so the table shows the photo as "up to" that size, with no minimum. The signature gets a box in millimetres and no pixel size. The 80KB and the minimum resolution of 150 px/inch cover both files.
| Upload | Pixels | File size | Format | Background |
|---|---|---|---|---|
| Photograph | up to 1200 × 1200 px | up to 80 KB | .jpg or .jpeg | White |
| Signature | Not set 8 × 3.5 cm at most | up to 80 KB | .jpg or .jpeg | Not stated |
Photograph: the notice's words
“Upload the scanned image of your passport size photo within the dimensions of 1200 pixels x 1200 pixels.”
“The documents file format should be a .jpg or .jpeg and the file size should not be more than 80KB each.”
“The image should be clear with a minimum resolution of 150px/inch.”
“The photo should not be more than 6 months old and should have a white background.”
Name and date on the photo: Not asked for: no CAT 2026 document mentions a name or date on the photo.
Signature: the notice's words
“Also, upload the scanned image of your signature within the dimensions of 80mm X 35mm.”
“The documents file format should be a .jpg or .jpeg and the file size should not be more than 80KB each.”
What the tool makes: your crop's own pixels, up to 472 × 206 px (the most that fits 80 × 35 mm at 150 px/inch; worked out, not a CAT pixel size); 150 DPI written into the file, from the guide's 150 px/inch, which covers both images. These are worked out from the notice's numbers, not stated in it.
How to use the CAT photo and signature resizer
- Scan a recent photo (not more than 6 months old) and your signature with a scanner, as CAT's form asks, and choose the scans in cards 1 and 2. Keep Your photo's shape, or pick Square first.
- Zoom and drag the photo until your face is centred, and tap Make the background white if the background isn't white. Frame the signature; Whiten the paper clears a grey scan.
- When both checklists are green, download the photo and the signature, each up to 80 KB, and upload them. Keep prints of the same photo for test day.
Example: a phone photo through the CAT resizer
- Photograph: a 12-megapixel phone photo, 3,000 × 4,000 px, opens as a 1,800 × 2,400 px copy; with no shape set, the frame is the whole 1,800 × 2,400 px, drawn smaller, at 900 × 1,200 px. The JPEG is at most 80,000 bytes (up to 80 KB) with 150 DPI, named cat-photo-900x1200.jpg. Over the limit even at 60% quality, it would get fewer pixels, same shape.
The JPEG quality it lands on depends on the picture itself.
Why the photo keeps its shape, and a 472 × 206 signature
CAT gives limits, not sizes. For the photo the only stated limit is the 1200 × 1200 box, so the tool keeps your scan's own shape and pixels and only scales it down to fit inside the box; a small scan isn't blown up to fill it. If the file would be over 80 KB at 60% JPEG quality, the photo gets smaller instead of blurrier. The square choice frames the same photo as a square, for anyone who prefers it.
For the signature, 80 mm at 150 px/inch is 472.4 pixels and 35 mm is 206.7, so the largest signature that stays inside the box is 472 × 206 px, rounded down so it doesn't spill over 35 mm. The tool keeps your signature's own shape inside that, and writes 150 px/inch into both files, so each one measures inside its limit.
Scanner, test day and the edit window
The note in the guide's screenshot of the upload panel says to scan with a scanner only, never a mobile phone or mobile app. On test day, FAQ Q19 says admit cards, photo IDs, candidate pictures and biometric information are verified at the centre, and the guide asks you to affix a print of the photo you uploaded on your admit card for the test on 29 November 2026. CAT 2026 allowed photo and signature changes only in the edit window on 5 and 6 October 2026, so for CAT 2027 get both right before you submit.
Why CAT uploads get rejected
The CAT 2026 guide doesn't list rejection reasons for the photo or signature. These are the rules it sets, and what's checked on test day:
- The guide's limits for both files: .jpg or .jpeg, not more than 80KB each, and a minimum resolution of 150px/inch; the photo within 1200 × 1200 px and the signature within 80mm X 35mm.
- A photo more than 6 months old, or without a white background, goes against the guide.
- On test day, admit cards, photo IDs, candidate pictures and biometric information are verified at the centre (FAQ Q19), and a printed copy of the photo you uploaded is affixed to your admit card.
How the tool reaches the KB range
Each file is drawn at its own pixels, scaled down to fit its box, and saved as a JPEG at the highest quality that stays under 80 KB, found by halving the gap between a too-big and a small-enough quality about seven times. If even 60% quality is too big, the pixel size goes down, keeping the shape, and the search runs again. There's no minimum file size, so nothing is added to the file. The checklist is read from the finished file.
Check before you apply
- The guide's sizes are limits ("within the dimensions of"), not exact sizes or shapes. A smaller photo or signature of any shape inside them is also within the rule.
- The form links to "Photo Specification and Sample Photos" inside the logged-in application; it couldn't be opened for this page and may add a shape or face-size rule. Look at it when you apply.
- No official CAT 2026 document gives the photo a size in mm or cm; sizes quoted elsewhere aren't from IIM sources.
- CAT 2026 registration closed on 22 September 2026, and the photo and signature edit window closed on 6 October 2026. The CAT 2025 and 2026 guides use the same wording; check the CAT 2027 Registration Guide when it's out (usually late July).
- Category and PwBD certificates are PDF uploads in the same form; they're not part of this tool.
Sources
Rules on this page and in the tool are as per the CAT 2026 Registration Guide dated 29 July 2026; check the latest notice before you apply. We read the official sources below on 8 October 2026 (CAT 2026: registration 3 August to 22 September 2026, photo and signature edit window 5–6 October 2026, test on 29 November 2026) and will check them again by 1 August 2027.
- CAT 2026 Registration Guide ↗, dated 29 July 2026
- CAT 2026 Information Bulletin (V2) ↗, dated 26 July 2026
- CAT 2026 FAQs ↗, read on 8 October 2026
- CAT 2026 media release: limited edit window ↗, dated 29 September 2026
- CAT 2025 Registration Guide (same wording, for comparison) ↗, read on 8 October 2026