Signature size should be at least 20 KB: how to fix it
The form thinks your signature file is too small. Pick your exam in the tool, drop the signature photo, and it comes out at that exam's size. If a clean JPG at that size is still under the minimum, the tool adds blank comment data inside the file until it clears the minimum. The signature itself does not change.
The tool runs in your browser and nothing is uploaded. Updated 24 October 2026.
1. Choose
- Pixels:
- about 350 × 350 px
- File size:
- 20–100 KB
- Format:
- JPG
- Background:
- white
Source: UPSC Civil Services (Preliminary) Examination, 2026 — Examination Notice No. 05/2026-CSE (4 Feb 2026), checked 3 Oct 2026
Change the output size
The notice gives an approximate size, so you can pick another one close to it.
2. Fix
JPG, PNG, WebP or HEIC (where the browser can open it). Large phone photos are fine.
Nothing is uploaded. Everything runs on this device.
What "Signature size should be at least 20 KB" means
A signature is black ink on white paper, and that compresses very well. At the small pixel sizes forms ask for, a clean signature often ends up between 5 and 15 KB, which is under a 20 KB floor.
In our exam data the UPSC forms (20 to 100 KB) and India Post GDS start their signature window at 20 KB. Compressing again only makes the file smaller. You need a bigger file: more pixels, a higher JPG quality, or padding.
Why it happens
- The file was made for another form, such as a bank form that caps the signature at 20 KB, and it ended up well under 20 KB.
- The signature was cropped tight and saved in black and white, so there is very little left to store.
- WhatsApp or a phone app shrank the image before you saved it.
- The form counts 1 KB as 1,024 bytes. A file your phone calls 20 KB may be 20,000 bytes, which is 480 bytes short.
Exams whose signature must be at least 20 KB
- India Post GDS · 300 × 120 px, 20 to 50 KB
- UPSC CAPF AC · 350 × 350 px, 20 to 100 KB
- UPSC CDS · 350 × 350 px, 20 to 100 KB
- UPSC CSE · 350 × 350 px, 20 to 100 KB
- UPSC ESE · 350 × 350 px, 20 to 100 KB
- UPSC Geo-Scientist · 350 × 350 px, 20 to 100 KB
- UPSC NDA · 350 × 350 px, 20 to 100 KB
From each exam's latest notification in our data. Each exam page shows its source and the date we checked it.
Tips
- Start from the original phone photo of the signature, not from a file you already compressed for another form.
- For UPSC, sign three times, one below the other, on plain white paper in black ink. The UPSC upload instructions ask for that triple signature.
- Aim for 21 or 22 KB rather than exactly 20. The tool already lands about 1 KB over the minimum.
- Check the maximum too. UPSC allows up to 100 KB, so there is plenty of room above 20.
Other upload errors
Rejected for something other than size? See photo rejected and signature rejected. Only need the file smaller? Use compress to KB.
Frequently asked questions
- Why does my signature keep coming out under 20 KB?
- Black ink on white paper has very little detail, so a JPG of it is small. The tool here keeps the exam's pixel size and, when the clean file is still under 20 KB, pads it to just over the minimum.
- Should I scan the signature in colour to make it bigger?
- Colour adds a little, but not reliably enough. Keep the ink black and the paper white as most notices ask, and let the tool take care of the size.
- Is it all right to pad the file to reach the minimum?
- The padding is a comment block inside the JPG. Image viewers skip it, so the picture is exactly the same; only the byte count goes up. If your notice tells you a different way to reach the minimum, such as a larger pixel size, do what the notice says.