Compress Signature for CTET 2026 — Free, Fast & Private
The CTET signature spec, as CBSE prints it
| Format | JPG / JPEG |
|---|---|
| File size | 3–30 KB |
| Pixels | not stated |
| Shape | no ratio stated |
| Print size | 3.5 cm × 1.5 cm (width × height) |
| DPI | not stated |
| Other rules |
|
The official wording
Size of scanned signature should be between 3 KB to 30 KB.
Source: CTET September 2026 — Information Bulletin (CBSE), p. 3 (May 2026) — checked 5 October 2026
Only need the signature under 30 KB, with no pixel rules? Compress image to 30 KB aims at that size alone; the tool on this page also checks the lower limit.
The rule sits in the CTET September 2026 — Information Bulletin (CBSE) (p. 3), and it is one sentence: Size of scanned signature should be between 3 KB to 30 KB.
The bulletin also gives the image dimension, 3.5 cm × 1.5 cm. That is the whole specification. The bulletin names no pixel count, no scanner resolution and no ink colour for this file, so what follows separates what CBSE states from what is only good practice.
A shape in centimetres, a limit in kilobytes
CBSE describes the signature the way a printed form does: a strip 3.5 cm × 1.5 cm in size. An upload box has no centimetres, only pixels, so the shape is a guide for the crop rather than something a portal can measure. The tool above checks the part that can be measured, the file size and the format. The shape is yours to get right when you crop.
A strip that wide and that short is a ratio of about 2.3 to one. Cropping a phone photo of a signature to that ratio before compressing keeps the file small for the right reason: you have removed blank paper rather than detail from the ink.
Where a CTET signature file goes wrong
The window runs from 3 KB up to 30 KB. The floor is low, so the common failure is a file that comes out of a scanner or a phone far above the ceiling: paper grain and shadow are expensive to encode, and a signature is mostly paper. The tool counts the ceiling the strict way, 30,000 bytes, and the floor the strict way, 3,072 bytes, so a file that passes both passes whichever reading the portal uses.
The opposite failure is rarer but real. Crop hard, shrink the picture and apply heavy compression, and a pale signature can fall under the floor; the tool reports which end it missed. Our advice, not a CBSE rule: sign with a dark pen on plain white paper, photograph it flat in daylight, and crop with a thin margin.
- Sign once on plain white paper, at your normal size.
- Photograph or scan it flat, then crop the strip to the shape above.
- Drop it into the tool and read the exact size it shows.
- Upload the JPEG in the signature field of the CTET application.
Common rejection reasons
The CTET September 2026 notice lists no separate rejection causes for the signature beyond the specification above. Every cause the exam bodies do state is collected, with its page, on the exam rejection reasons page.
The photograph is a separate file
The application asks for two images with different bands. The photograph has its own limits, 10–100 KB, set out on the CTET photo page; the two ranges overlap, but each upload is a different picture, so make each file against its own table. If all you need is a general file under 30 KB with no CTET checks, the 30 KB compressor aims at that size alone. Every exam MiniPx has checked against its notice is on the government exams hub.
The compression runs in your browser. The signature is not uploaded to MiniPx.