Reduce Photo Size in KB on Your Phone (Android & iPhone)

A photo from a modern phone is usually 2–6 MB and 3000–4000 pixels wide. Most application forms want something like 20–50KB at a few hundred pixels. That is a 50–100× reduction, and how you do it decides whether the result looks sharp or blocky.

Why File Size Depends on Two Things

The KB size of a JPG depends mainly on:

1. Pixel dimensions — a 4000×3000 photo has 12 million pixels; a 200×230 photo has 46 thousand. Fewer pixels means far fewer bytes.
2. JPEG quality — lower quality throws away fine detail to save bytes.

The right order is: first set the exact pixel size the form asks for, then lower quality only as much as needed. Doing it the other way round — squeezing a full-size photo down with very low quality — produces the blotchy, smudged faces that portals and verifiers reject.

Step by Step

1. Take a fresh photo. Stand facing a plain light wall, about an arm's length from a window. Avoid night mode and zoom; both add noise that costs bytes.
2. Find the exact requirement in your notification: width × height in pixels and the minimum–maximum KB. If the form only gives a maximum (for example "under 50KB"), aim for 60–90% of it.
3. Open a resizer that works in your browser. On Resize Image in KB, pick the KB limit, enter the pixel size, and choose your photo. Nothing is uploaded, so it works for ID documents too.
4. Crop, don't stretch. Drag the frame so your face and the top of your shoulders fill it. Stretching a photo into a different shape makes faces look too wide or too thin.
5. Download and check the size and dimensions shown before you upload. A good result is inside the range with a small margin, not exactly on the limit.

For common targets there are pages with the size already selected: 20KB, 50KB, 100KB and 200KB.

Shortcuts That Usually Fail

• Sending the photo to yourself on WhatsApp. It shrinks the file but to an unpredictable size and shape, and often not below the limit.
• Screenshotting the photo. A screenshot adds your screen's resolution and status bar, and is usually a PNG — a different format.
• Renaming the file extension. Changing photo.png to photo.jpg does not convert it; many portals check the real format and reject it.
• Using the phone's "Small" camera setting. It lowers pixels but not to the exact size, and quality settings vary by phone.

iPhone Notes

iPhones save photos as HEIC by default. Many portals accept only JPG/JPEG. Either convert first with HEIC to JPG, or use a resizer that reads HEIC directly (the KbSnap tools do). To avoid HEIC in future: Settings → Camera → Formats → Most Compatible.

Android Notes

Some Android galleries show "Edit → Resize", but the result is a fixed percentage, not an exact pixel size, and it does not let you choose a KB limit. The camera app may also add a watermark ("Shot on…") — turn it off in camera settings before taking an exam photo.

If the Photo Still Won't Fit

• Too big at the lowest sensible quality? The pixel size is probably larger than required — check the notification again. A plain background also helps a lot.
• Too small (below the minimum KB)? Rare, but it happens with very small pixel sizes. Increase quality, or open your exam in the exam directory — exam pages aim for a size inside both the minimum and maximum.
• Portal still says "invalid"? Read Why Was My Exam Photo Rejected? for the other common causes.