What RRB asks for
CEN 06/2026 (NTPC Graduate) sets the signature rule in para 14.5.1 and the live photo in para 14.4, and CEN No. 04/2026 JE/DMS/CMA, CEN No. 01/2026 Assistant Loco Pilot and CEN No. 09/2025 Level-1 (Group D) say the same. The table has the one upload RRB takes; the CEN's own words follow. The 140 × 60 px is a minimum, and the 3.5 × 2 cm is the scan box on the form.
| Upload | Pixels | File size | Format | Background |
|---|---|---|---|---|
| Signature | at least 140 × 60 px 3.5 × 2 cm the tool makes 140 × 80 px, worked out | 30–49 KB | JPG/JPEG | White paper, black ink pen |
Signature: the notice's words
“Scan the signed paper using a minimum resolution of 100 DPI.”
“Image file format: JPG/JPEG only.”
“File size: Between 30 KB and 49 KB.”
“Image dimensions: Minimum 140 pixels (width) x 60 pixels (height).”
“Box size: 35 mm (width) x 20 mm (height).”
“NOT in BLOCK, CAPITAL, or DISJOINTED letters”
What the tool makes: 140 × 80 px (the 35 × 20 mm box's shape at over 100 DPI, and at least the CEN's 140 × 60 px). These are worked out from the notice's numbers, not stated in it.
How to use the RRB signature resizer
- Sign in black ink on white paper, in your usual joined-up handwriting, inside a 35 mm × 20 mm box (draw one with a ruler if your form doesn't give you one).
- Scan it at 100 DPI or more, or take a straight phone photo in daylight. Choose it, drag or zoom until the 35 × 20 mm box fills the frame, with the signature centred in it, and tap Whiten the paper.
- When the checklist is green, download the 140 × 80 px file (30–49 KB) and upload it in the signature step of the form.
Example: a phone photo through the RRB resizer
- Signature: a 12-megapixel phone picture of the paper, 4,000 × 3,000 px, opens as a 2,400 × 1,800 px copy; the frame at the worked-out 140 × 80 px (the 35 × 20 mm box's shape at over 100 DPI, and at least the CEN's 140 × 60 px) covers 2,400 × 1,371 px, drawn smaller, at 140 × 80 px. The JPEG is 30,720 to 49,000 bytes (30–49 KB), named rrb-signature-140x80.jpg. Under 30,720 bytes at full quality, an invisible comment makes up the rest.
The JPEG quality it lands on depends on the picture itself.
Why the tool makes 140 × 80 px
The CEN's one pixel figure is a minimum: “Image dimensions: Minimum 140 pixels (width) x 60 pixels (height).” It states no maximum, and it hasn't been confirmed whether rrbapply.gov.in checks one. What the CEN does fix is the box: “Box size: 35 mm (width) x 20 mm (height).”, scanned at 100 DPI or more. A file of exactly 140 × 60 px is 2.33 times as wide as it is high, so it can't hold the whole 35 × 20 mm box, and 60 px across 20 mm is only about 76 dots per inch. So the tool frames the file at the box's own shape (35:20) and makes it 140 × 80 px: the CEN's minimum width, at least 140 × 60 px, and 101 dots per inch across the box. That pixel size is our choice, worked out from the CEN's numbers, not an RRB figure. A signature that small is always well under 30 KB, even at full JPEG quality, so the tool adds an invisible comment to the file to bring it just over 30 KB; the picture is exactly what you framed.
Signing the way RRB checks it
Write your signature in running (joined) handwriting, “NOT in BLOCK, CAPITAL, or DISJOINTED letters”, with a black ink pen on white paper. Sign it the same way every time: your signature is matched at the computer-based test, document verification, medical exam and joining. At the test centre you also write a self-declaration paragraph in front of the invigilator, sign it and put your left thumb impression on it; writing it in advance or signing in capitals leads to rejection. Persons with Benchmark Disabilities who can't sign may upload a scanned fingerprint in the signature slot instead, in this order: left thumb, right thumb, any finger of the hands, any toe.
The live photo in the RRB form
RRB doesn't take a photo file. The application captures a live photo with your computer's webcam or your phone's front camera, and you can preview and retake it until you submit. CEN 06/2026 asks for a pure plain white background, your head filling at least half of the photo and nothing below your chest showing. Wear non-white, preferably plain dark clothes that cover your shoulders and chest, take off any cap, mask or spectacles, and keep your eyes fully open, or the photo won't be captured.
“Candidates are not required to upload a pre-existing photograph while applying.”
What CEN 06/2026 asks of the live photo, para 14.4:
- “Live photo must be taken with pure plain white background without any scenery, plants/human or animal picture.” This line is new in CEN 06/2026; the earlier CENs only asked for non-white clothes, preferably dark, to contrast with the background.
- “the head portion should occupy at least 50% of the total area of the photo.” Your elbows and anything below your chest shouldn't show.
- Camera at eye level, looking straight ahead with a neutral expression, face centred in the on-screen frame, with no shade on it and no strong light behind you.
- No cap, mask, glasses or spectacles, and your face not hidden by hair or cloth. Keep your eyes fully open, or the photo won't be captured.
- You can preview and retake it until you submit the application.
Why RRB uploads get rejected
- Signature grounds for rejection: someone else's signature, a background that isn't white, ink that isn't black, block or capital letters, poor resolution, an incomplete signature, the wrong image, a blank image, or a thumb impression in place of the signature.
- Taking the live photo of a printed or digital photo, instead of your face, leads to summary rejection.
- At the computer-based test you write the self-declaration paragraph, sign it and put your left thumb impression on it in front of the invigilator. Writing the paragraph in advance or signing in capital letters leads to rejection.
- If your live photo doesn't match your photo ID, you have to upload an annexure signed by a Gazetted Officer (Annexure VIII in CEN 06/2026).
How the tool reaches the KB range
The signature is drawn at 140 × 60 px and saved as a JPEG at the highest quality under 49 KB, which at this size is full quality. That file is far below 30 KB, so an invisible comment is added after the JPEG header until the file passes 30 KB; the image data isn't changed. The checklist reads the pixels, size and format back from the finished file. For forms that take a photo file, use the Passport Size Photo Maker; for any other size in KB, Increase Image Size in KB.
Check before you apply
- The CEN gives 140 × 60 px as a minimum and no maximum, and puts the signature in a 35 × 20 mm box scanned at 100 DPI or more. The tool makes 140 × 80 px: the minimum width at the box's shape, which is more than 100 dots per inch across the box. That pixel size is the tool's choice, not an RRB figure. A picture that small is always far under 30 KB, even at full quality, so the tool adds an invisible comment to the file to reach 30 KB; the picture is unchanged.
- It isn't confirmed whether the signature step on rrbapply.gov.in enforces a maximum pixel size or a fixed shape. Until it is, the tool keeps to what the CEN states: at least 140 × 60 px, 30–49 KB, JPG/JPEG.
- The official FAQ for CEN 09/2025 (Q51) still says photo 40-70 KB and signature 30-70 KB. That is left over from when photos were uploaded; the detailed CENs say live photo and a 30-49 KB signature, and the CEN governs.
- Bring a colour passport photo not older than two months to the computer-based test, document verification and medical exam. The CEN gives no size for it, and none for the photo and signature scans you upload later at document verification.
- The NTPC Undergraduate 2026 CEN wasn't out on 8 October 2026: check its signature rule when it is.
Sources
Rules on this page and in the tool are as per the RRB CEN No. 06/2026 Non-Technical Popular Categories (Graduate) dated 7 October 2026; check the latest notice before you apply. We read the official sources below on 8 October 2026 (CEN 06/2026 NTPC (Graduate), applications 8 October to 6 November 2026; the same rules are in CEN 04/2026 JE/DMS/CMA, CEN 01/2026 ALP and CEN 09/2025 Level-1) and will check them again by 1 January 2027.
- RRB CEN No. 06/2026 Non-Technical Popular Categories (Graduate) ↗, dated 7 October 2026
- RRB CEN No. 04/2026 JE/DMS/CMA ↗, dated 13 August 2026
- RRB CEN No. 01/2026 Assistant Loco Pilot ↗, dated 14 May 2026
- RRB CEN No. 09/2025 Level-1 (Group D) ↗, dated 31 January 2026
- RRB FAQ for CEN 09/2025 Level-1 (Q51 has outdated photo and signature sizes) ↗, dated 4 February 2026
- RRB notice on pasting a photograph on the e-call letter, CEN 05/2025 ↗, dated 17 February 2026