Compress Photo for CTET Application | MiniPx — Free, Fast & Private
CBSE prints the CTET upload rules in the information bulletin for each cycle, under Step 3: Upload Scanned Images of latest Photograph and Signature. Four lines, and all four are enforced:
- Photograph — JPG/JPEG, 10 KB to 100 KB, image dimension 3.5 cm wide × 4.5 cm high.
- Signature — JPG/JPEG, 3 KB to 30 KB, image dimension 3.5 cm long × 1.5 cm high.
- Both uploads are mandatory, and the photograph you submit is matched against you at the examination centre — so it has to be a recent likeness, not an old file that happens to be the right size.
CBSE gives centimetres. Your file is in pixels.
This is the part that confuses people, and it is worth being precise about: the bulletin specifies the photograph in centimetres, not pixels. A JPEG has no inherent physical size — centimetres only become pixels once you fix a resolution. So you choose the DPI, and the choice decides your pixel count:
- At 300 DPI: 3.5 × 4.5 cm becomes roughly 413 × 531 px — print quality, and a larger file.
- At 200 DPI: roughly 276 × 354 px — comfortably sharp on screen and much easier to fit under 100 KB.
- At 96 DPI: roughly 132 × 170 px — too small; the face goes soft when the examiner compares it to you.
Aim somewhere between 200 and 300 DPI. What actually matters to the portal is the 3.5 : 4.5 aspect ratio and the file size band; a photo at that ratio and a sane pixel count passes. Note that no pixel dimension appears anywhere in the bulletin — if a site tells you CTET requires 200 × 230 pixels, that number is not from CBSE.
The signature band is the tight one
A photograph has 90 KB of headroom between floor and ceiling. The signature has 27. And a flatbed scan of a signature on white paper, saved straight out of the scanner software, routinely lands at 150–400 KB — five to ten times over.
The reason is that scanners capture paper texture, and JPEG spends real bytes encoding that speckle. Crop tightly to the signature itself before compressing: whitespace is not free, and cropping is the single most effective move here. Then compress at JPEG with a small max width — around 350px is plenty for a 3.5 cm strip — and check the result against the 3 KB floor as well as the 30 KB ceiling.
Why your CTET upload was rejected
File too large. The usual cause, and the easiest to fix — drop the max width and re-compress.
File too small. Less obvious and just as fatal. Below 10 KB for a photo, or 3 KB for a signature, the portal refuses the file. Advice to “compress as much as possible” is actively wrong for CTET; both limits bind.
Wrong shape. A square crop, or a landscape phone photo, is not 3.5 : 4.5 however small the file. Crop to portrait proportions first.
Wrong format. PNG and HEIC are not JPG. An iPhone photo is HEIC by default — converting it is a required step, not an optional one.
MiniPx shows the exact output size before you download, so both bounds can be checked rather than guessed. Nothing leaves your device: your photograph and signature are processed entirely inside your browser.
The conversion above is standard print arithmetic — why DPI does nothing on screen but decides everything in print covers it in full.