Compress image to 30 KB:
for online forms

Where a 30 KB limit comes from

Upload limits are chosen by whoever built the form, usually to keep a database of thousands of applicants small. The FPSC guidelines, for example, ask for a recent passport-size picture in JPG or JPEG under 30 KB; our FPSC photo size page covers that form on its own.

If your form gives a range such as 10 to 30 KB, the minimum rarely matters for a photo: the result usually lands close to the top of the range. It is mostly scanned signatures on white paper that come out too small.

What 30 KB buys over 20 KB

• On a cropped portrait, the tool can usually keep more of the pixels and a higher JPEG quality than at 20 KB, so the face looks less blocky.
• On an uncropped phone photo the gain is smaller in proportion: the picture is still scaled down a great deal, just slightly less than at 20 KB.
• On a signature, both sizes are plenty once the paper has been cleaned to white.

Getting a sharp result at 30 KB

1. Take the photo against a plain, light wall. Patterned walls, shelves and plants all cost bytes.
2. Crop to head and shoulders with Passport size photo maker or Crop image before compressing. Fewer pixels to store means more quality for each one.
3. Add the cropped picture here. The tool tries a high JPEG quality first and lowers it only as far as needed.
4. If the form gives exact pixel dimensions as well, use Resize image instead and set its File size limit to Under 20 KB, the closest of its choices below 30 KB.

How the tool reaches 30 KB

The JPEG is first saved at 92% quality. If that is over 30,000 bytes, the tool searches between 92% and 40% for the highest quality that fits. When even 40% is too big, it scales the picture down a step and searches again. The result is the largest, cleanest version it finds that stays at or below the limit.

Because 1 KB is counted here as 1,000 bytes, a 30 KB result is a little smaller than a form that counts 1,024 bytes per kilobyte would allow. That small margin is deliberate.

When the portal still refuses it

• Check you picked the new file: it is the one whose name ends in .jpg in your Downloads folder.
• Read the error. “Invalid format” usually means the form wants JPG, which this is, or PDF, which it is not.
• “Dimensions not allowed” means the form also checks pixels. Set those with Resize image.
• If the picture is rejected after review for being unclear, retake it in daylight rather than lowering the size further.