Short answer: Target 40–48 KB when the portal limit is 50 KB, and 18–19 KB when the limit is 20 KB. Always stay 2–3 KB under the stated maximum — portals use strict byte-level checks, and "50 KB" on an Indian government portal typically means 51,200 bytes, not 50,000 bytes. A file that your file manager shows as 50 KB can still fail.
The tool above lets you enter any exact KB target. Use it with the table below to find your portal's limit and compress accordingly.
Master Table — Every Major Exam Portal's Photo Size Limit
| Portal / Exam | Photo size | Signature size | Format |
|---|---|---|---|
| SSC CGL / CHSL / MTS / CPO | 20–100 KB | 10–20 KB | JPEG |
| IBPS PO / Clerk / SO / RRB | 20–50 KB | 10–20 KB | JPEG |
| SBI PO / Clerk | 20–50 KB | 10–20 KB | JPEG |
| NTA NEET / JEE Main / CUET | 10–200 KB | 4–30 KB | JPEG |
| UPSC Civil Services (IAS) | 40–300 KB | 3–300 KB | JPEG |
| RRB Group D / NTPC | 20–50 KB | 10–40 KB | JPEG |
| NSP Scholarship | 20–50 KB | — | JPEG |
| Passport Seva (online) | 20–50 KB | — | JPEG |
| DigiLocker (document images) | Up to 500 KB | — | JPEG / PNG |
| EPFO / UAN portal | 20–50 KB | 10–20 KB | JPEG |
When Should You Use 20 KB?
Use 20 KB (or the 10–20 KB range) for:
- Signature uploads on all exam portals — Almost every exam form has a separate signature slot with a 20 KB maximum. Never upload a 50 KB photo as your signature — it will be rejected.
- Older state scholarship portals — State-level portals (some state NIC portals) often have stricter limits of 10–30 KB that predate modern bandwidth assumptions.
- Some railway and RRB forms — A few RRB portals specify 20 KB for the photo even though the main spec allows 50 KB. Always check the current year's notification.
When Should You Use 50 KB?
Use 40–48 KB (safely under the 50 KB limit) for:
- IBPS, SBI, and all bank recruitment portals
- Passport Seva digital upload
- NSP and most central government scholarship portals
- EPFO and PF-related portals
The 2–3 KB Safety Rule — Why Not to Submit at Exactly the Limit
Indian government portals inconsistently define "kilobyte". Some use 1 KB = 1,000 bytes (decimal); others use 1 KB = 1,024 bytes (binary). A file your operating system reports as 50 KB might be 51,200 bytes — which is over the limit on a portal using the binary definition.
The practical rule: subtract 2–3 KB from the stated maximum and compress to that target. For a 50 KB portal, target 47 KB. For a 100 KB portal, target 96 KB. The quality difference is invisible to the human eye at these sizes.
Use the custom KB compressor above to enter any exact target — type "47" for a 50 KB portal, or "18" for a 20 KB portal.
What Happens If You Submit the Wrong Size?
The outcomes vary by portal:
- "File size exceeds the maximum limit" — The file is rejected immediately, and you must re-upload. This is the best outcome — it is obvious and fixable.
- "Invalid file format or dimensions" — Some portals throw this generic error when the file is too large, even though the format is correct. If your format is definitely JPEG, try compressing smaller.
- Session lock / timeout — A few portals lock the form for 30–60 minutes after repeated failed uploads. Prepare your files before starting the form to avoid this.
- Silent acceptance of wrong size — Rare, but some portals accept oversized files during upload but flag the application during document verification. This is the worst outcome because you only discover it months later.
Quick Reference — Which Tool to Use
- IBPS, SBI, Passport Seva, NSP: Compress to 50 KB
- SSC CGL / CHSL photo: Compress to 100 KB
- Signatures (all portals): Compress to 20 KB
- NEET / JEE / CUET photo: Use custom target of 150–180 KB
- Any other portal: Custom KB compressor — type your exact target
See also: SSC CGL photo upload errors and NEET 2025 photo upload guide with error codes.