How to Resize the Thumb Impression for RBI Grade B / Assistant
RBI Grade B (Officer) and RBI Assistant both currently require this left thumb impression at 240×240 pixels, 20-50KB, JPG. Take the impression on plain white paper, photograph it clearly, upload it here, keep the default dimensions, and download the processed JPG — the tool targets 35KB by default, the midpoint of RBI's range, leaving margin for portal checks while keeping ridge detail visible.
Because RBI Grade B and RBI Assistant are separate recruitment cycles with their own application calendars, even though the thumb impression specification is identical, take a fresh impression for each application rather than reusing one file across both.
RBI Grade B vs RBI Assistant — Same Spec, Different Recruitment
The thumb impression specification is identical for both RBI tracks — 240×240px, 20-50KB, left thumb only. What differs is the role and exam structure: RBI Grade B is an officer-entry post with a prelims/mains/interview structure and postings across RBI's regional offices, while RBI Assistant is a clerical-entry post with its own separate prelims/mains cycle. Confirm which application screen you're using, since the document upload fields are separate even when the spec matches.
How to Take a Clear Thumb Impression
Buy a small black stamp pad from a stationery shop — no special biometric product needed. Press the thumb on the pad once or twice with moderate pressure, checking ink coverage before placing it on paper. Use plain white paper with no ruled lines. Press the left thumb firmly, lift straight up without dragging, and let it dry for about 30 seconds.
Photograph the sheet on a flat surface in even light, holding the camera roughly 20cm directly above the paper. Avoid shadows and keep the shot square rather than distorted by a tilted angle. Too much ink creates a dark blob; too little hides ridge detail — test once on scrap paper first if unsure.
Why RBI Requires a Thumb Impression
RBI Grade B and Assistant recruitment, like other banking exams, uses the thumb impression as a backup identity marker — during document verification or joining formalities, RBI can compare the uploaded impression against a fresh one taken from the candidate in person. It's a standardized, paper-based identity document rather than a biometric scan, which is why it can be prepared at home with just an inkpad and plain paper.
Final Upload Checklist for RBI
Before uploading, confirm the file is JPG, 240×240 pixels, and between 20KB and 50KB. Open the final file once — the impression should be centered, dark enough to show ridge lines, and set against a clean white background with no hand, table surface, or shadows visible. Keep the original photo and processed JPG in a separate folder per RBI application (Grade B vs Assistant) if you're applying to both in the same cycle, to avoid mixing up files between them.
FAQ
240x240 pixels, 20KB to 50KB, JPG format — the same specification applies to both RBI Grade B and RBI Assistant.
Use the left thumb only. Banking application portals normally ask for left thumb impression. Uploading the right thumb can cause rejection unless the official notification gives a special alternative instruction.
Use black stamp pad ink on plain white paper. A small stationery-shop inkpad is enough. Do not rub pen ink directly on the thumb because it spreads unevenly and often smudges.
Use a fresher inkpad or apply slightly more pressure on the pad. Press the left thumb firmly on paper and retake the photo in better light.
Yes. Use the rear camera, bright light, direct top-down angle and a steady hand. Keep the paper flat and avoid shadows on the impression.
Upload it here, keep the default 240x240 dimensions and 35KB target, then download the JPG. The output stays within the banking 20KB to 50KB range.
Yes, if it has clean black ink and gives a sharp print. Old or dry pads create faint ridges, so test once on rough paper before the final attempt.
Use plain white unlined paper only. Lines, printed marks and colored paper can confuse verification and make the final image look unprofessional.
Yes. Always retake a smudged impression. Compression cannot restore ridge detail when the source print is dragged or blurred.
The specification is the same, but taking a fresh impression for each application is safer since each is tracked and verified independently.
Yes. The common minimum is 20KB. A file below that may be rejected by the portal or may become too compressed for visual checking.
It is simply the clean white background around the impression. Keep it free from stray ink marks so the thumb pattern stands out clearly.
They are not recommended. Press the thumb directly on the stamp pad because it gives natural and even ink distribution across the ridges.
Use one clear final impression. If the first attempt is poor, use a fresh area or fresh paper instead of placing multiple impressions together.
Retake the impression with better ink, white paper, good light and direct camera angle. Then process it again to 240x240 pixels and 20KB to 50KB.