RRB Signature Size: 30 to 49 KB, 140 x 60 Pixels

From the RRB FAQs for CEN 06/2025 (NTPC) and CEN 02/2025 (Technicians), published on official RRB websites (checked on 10 October 2026). Each CEN has its own notice, so check the one you are applying under.

• Signature written by the candidate only, with a black ink pen on white paper.
• Running handwriting (joined letters), not block, capital or disjointed letters.
• Scanned at a minimum of 100 DPI.
• JPG or JPEG only, between 30 KB and 49 KB.
• At least 140 pixels wide and 60 pixels high. This is a minimum, not a fixed size.
• On the form, the signature sits in a box 35 mm wide and 20 mm high, centred.
• SC/ST certificate (only for the free train travel pass): PDF, under 400 KB.

A signature is mostly white paper, and JPEG compresses white paper extremely well. A 140 x 60 pixel signature is only 2 or 3 KB, far under the 30 KB minimum, so the form rejects it. The fix is not to blow up a tiny image, which makes it blurry, but to start from a larger, sharper scan and save it at a higher quality.

A good target is the same shape as the 35 x 20 mm box at a higher resolution, for example 700 x 400 pixels. That is well above the 140 x 60 minimum and gives JPEG enough detail to land in the 30 to 49 KB window.

1. 1

   Sign inside a 35 x 20 mm box

   Draw a light box 35 mm wide and 20 mm high on white paper and sign inside it in running handwriting with a black pen, filling most of the box.

2. 2

   Scan or photograph it sharply

   Scan at 200 to 300 DPI, or photograph the paper flat in daylight with no shadow across it. A sharp source is what makes the file both legible and large enough.

3. 3

   Crop to the box

   Open Crop Image, choose Freeform and crop to the box edges so the signature is centred.

4. 4

   Resize to 700 x 400 pixels

   In Resize Image, click the padlock between width and height to unlock the aspect ratio and enter 700 x 400. The 35 x 20 box has the same 7 to 4 shape, so nothing is distorted.

5. 5

   Tune the quality into 30 to 49 KB

   Open Compress to 50 KB, change the maximum to 49, tick "The form also has a minimum size" and enter 30. The tool searches the JPG quality (and enlarges the image slightly if needed) until the file lands between 30 and 49 KB. Avoid quality 100 if you do it by hand: it overshoots to 100 KB or more.

If you are an SC/ST candidate requesting the free travel pass, scan the certificate, crop it, resize it to about 1400 pixels wide and compress it to around 200 to 300 KB, then convert it with JPG to PDF to get a PDF under 400 KB. The certificate must be valid as on the closing date of the application.

The application captures your photo live, so there is no photo file to prepare. The FAQs say you must not photograph a printed or on-screen picture, which leads to rejection. Wear dark, non-white clothes, sit in good light at eye level with the camera, and look straight ahead with a neutral expression.