Compress an image to 30 KB

What fits in 30 KB

A comfortable size for a signature, and workable for a small ID photo of roughly 200 x 230 px. A signature at 300 x 100 px will usually come out well under the limit, which leaves headroom if the form also sets a minimum. For a photo, grain starts to show once the background has any texture to it: a patterned wall or a curtain behind the subject costs a surprising share of the budget, because the encoder has to spend bytes describing detail nobody is going to look at.

Forms that cap uploads at 30 KB

These are real application forms whose own notice sets 30 KB as the maximum, read from the document linked below each figure. Specs change with every notification cycle, so check your own notice before you submit.

Read the CTET September 2026 Information Bulletin, STEP 3 notice

Getting the best result at this size

Shoot or scan against a plain light wall. A flat background compresses to almost nothing and leaves the whole budget for the face. If you are stuck with a busy background, crop tighter rather than compressing harder - removing pixels costs you nothing visually, while a lower quality setting degrades the face too. For a scanned signature, check it is genuinely black on white and not dark grey on cream; raising the contrast before you compress often halves the file on its own.

How the target is reached

The image is saved as a JPG at the highest quality that still fits in 30 KB (counted as 30,000 bytes), found by trying successive quality levels. Only if quality alone cannot get there is the image scaled down, in steps, keeping its proportions. The exact final size and dimensions are shown when it finishes.