Compress an image to 40 KB

Photo sizes that fit 40 KB

Here is the quality the tool reached when we fitted two test photos into 40 KB:

A passport-shaped photo at 300 DPI fits 40 KB with room to spare when the background is plain or soft. A busy background is what costs quality, so stand in front of a plain wall.

Is 40 KB a real form limit?

As a minimum, yes: Arunachal Pradesh PSC asks for scanned documents of 40 to 300 KB in its one time registration, so a scan must be at least 40 KB. As a maximum it is rare in the official rules we checked, which mostly use 10, 20, 30, 50, 100 and 500 KB. For a range, type both numbers, or tap 40 to 300 KB, and the tool keeps the file between them.

If your form says 50 KB, you do not need to aim lower to be safe. The tool already keeps the file under 50,000 bytes, which passes whichever way the site counts. Aim for 40 KB when the form says 40, or when you will add something to the image afterwards, such as your name and the date.

Centimetres and DPI at 40 KB

Many forms describe the photo as 3.5 x 4.5 cm rather than in pixels; the SSC CHSL 2022 notice and J&K BOPEE both do. Choose Exact size, switch to cm and set the DPI. At 200 DPI that is 276 x 354 pixels, which our busy street photo filled at quality 89 within 40 KB. The cm and KB page lists more of these conversions.

Sources, checked 13 October 2026: Staff Selection Commission (KKR), CHSL 2022 notice on photographs and signatures (PDF); J&K BOPEE, guidelines for scanning photograph, signature and thumb impression; Arunachal Pradesh PSC, one time registration instructions.