Compress image to
40KB online.
Compress a photo to a 40KB JPG — a common small-file limit on exam, admission and job forms. It is tight, but with a quick crop your photo still stays clear. Runs privately in your browser, no signup.
Need a different limit? Try 20KB JPG, 30KB JPG, or 50KB JPG. Uploading to a Pakistan board form? See the FBISE 40KB compressor. Need iPhone HEIC photos as JPG first? Use the HEIC to JPG converter.
Kodotools Team · Last updated: October 2026 · Files stay on your device
About this tool
Use this 40KB image compressor when a form caps the photo at 40KB — common on Indian exam, admission and recruitment portals, and the size Pakistan's FBISE boards use too. 40KB sits between a cramped 30KB and a roomier 50KB: small enough to clear a strict limit, but enough to keep a face recognisable after a tight crop.
Who needs this tool?
- Applicants on exam or admission forms with a 40KB photo limit
- Candidates uploading a small JPG to a job or recruitment portal
- FBISE and board-form users who need a 40KB photo
Drop your images here
or click to browse · select multiple
0 images ready
Total: —
Target size
Where 40KB is the ceiling
Forms with a 40KB limit
RRB uses 40KB as the top of both its photo and signature ranges, and FBISE caps board-form photos at 40KB. Usual specs below; check the notification you are applying to.
| Upload | Spec | What to do |
|---|---|---|
| RRB photo (NTPC, Group D) | 200×230 px, 15–40KB | Aim for 30–38KB |
| RRB signature | 140×60 px, 10–40KB | Aim for 20–30KB; signatures need less |
| FBISE photo (Pakistan) | Under 40KB | FBISE page has the board rules |
| SSC, IBPS photo | 20–50KB | 40KB passes; 45KB gives a bit more detail |
| Thumb impression | 240×240 px, 20–50KB | Thumb impression resizer |
Doing the photo and signature together? The photo and signature merger has an RRB preset.
"20KB to 40KB": hitting a range
Many forms give a range, not just a maximum. A file outside it on either side is rejected.
Aim for the middle
For a 20–40KB range, type 35 in the custom box. It is safely inside both ends and still sharp.
Came out under 20KB?
The image is too small to fill the range. Start from the original photo, not a WhatsApp copy, or use a slightly larger pixel size.
Still over 40KB?
Crop tighter and resize to the form's pixels (often 200×230) in the image resizer, then compress again.
FAQ
Common questions
How do I compress an image to 40KB JPG?
Upload your image, keep the 40KB preset selected, click Compress, then download the JPG. For a form photo, crop to head-and-shoulders first so 40KB has less to work with and the face stays clear.
How do I convert a photo to between 20KB and 40KB?
Type 35 in the custom KB box and compress. 35KB sits inside the 20–40KB range with room on both sides. If the result is under 20KB, start from a larger original photo.
What is the RRB photo size in KB?
RRB (NTPC, Group D) usually asks for a 200×230 px photo between 15KB and 40KB, and a 140×60 px signature between 10KB and 40KB. Always confirm in your notification.
Is 40KB enough for a signature?
Yes, easily. A 140×60 px signature is usually far below 40KB. If your form's signature limit is 10–20KB instead, use the 20KB page.
Is my image uploaded to a server?
No. All compression happens in your browser using JavaScript. Your image never leaves your device — not even for a millisecond.
Should the 40KB output be JPG or PNG?
JPG/JPEG is the only realistic choice at 40KB — a photo fits into 40KB far more cleanly as a JPG, while a PNG of the same photo is usually much larger. Use PNG only if your form specifically demands it.
Should I resize before compressing to 40KB?
At 40KB, yes — it makes a big difference. Crop to a tight head-and-shoulders portrait and bring it down to about 500px on the long edge first; that reaches 40KB with a usable face, whereas compressing a full phone photo to 40KB tends to look muddy.
Why is my compressed image still larger than 40KB?
At 40KB this usually means the image is still too large in pixels or very detailed. Crop out background and resize the dimensions smaller, then run the 40KB preset again.
Can I use this for passport, admission, or job form photos?
Yes — 40KB is a common photo limit on exam, admission and job forms, and on Pakistan's FBISE boards. Just confirm your form allows 40KB and check whether it also fixes an exact pixel size before uploading.
Guides
Real use-cases, step by step
Practical walk-throughs for the most common forms with strict size limits.