How to get a photo under a file size limit

Government portals, job sites and exam forms love a size limit: “JPEG only, between 20 KB and 200 KB.” A modern phone photo is several megabytes, so the upload fails and the error message does not say how to fix it. Here is how to get under the limit without wrecking the photo.

Read the limit carefully

Check three things on the form before you touch the photo.

• The maximum size, such as 100 KB, 200 KB or 1 MB. Some forms also set a minimum, so do not shrink past it.
• The format. Many forms accept only JPEG.
• Any pixel rules. “600 × 800 pixels” is a different rule from the file size, and both have to be met.

KB: 1,000 or 1,024?

A kilobyte is 1,000 bytes in the metric sense, which is how phones and most storage makers count. Older software counts in 1,024s, a unit more properly called a kibibyte. So a 200 KB limit might mean 200,000 bytes or 204,800 bytes.

You do not need to find out which one the form uses. Aim for the smaller count, 1,000 bytes per KB. A file that fits that is also under the limit by the larger count. The photo compressor counts this way, so the file it gives you fits either. If the form is strict, ask for a little less than the limit, such as 180 KB for a 200 KB cap.

Why fewer pixels beats lower quality

A file gets smaller in two ways. You can keep all the pixels and store each with less care (lower quality), or you can keep the care and use fewer pixels.

Lower quality is cheap at first and ugly later. JPEG works in small blocks, and when quality gets very low the blocks become visible: smears around edges, flat patches in the sky, mush in faces. Fewer pixels are gentler. A 12-megapixel photo shown on a screen is almost always displayed far smaller than 12 megapixels. Taking it down to 2 or 3 megapixels loses detail that nobody can see on a form, then a moderate quality setting fits the size limit comfortably.

So the rule is: shrink the pixels until the picture is a sensible size for its use, then let quality do the last bit of work.

The order to work in

If the form has both pixel rules and a size rule, do it in this order.

1. Resize to the pixel size the form wants, using the image resizer. For exact dimensions it crops the middle of the photo to the new shape.
2. Compress to the size limit with the compressor. Type the limit, choose JPEG, and press Compress.
3. Check the result. Look at the file size on your phone or computer, and confirm the pixel size if the form cares.

Doing it the other way around can undo your work. A resize after compression writes a new file at a new size, so the file size you carefully hit is no longer true.

The compressor tries quality levels until it finds the highest one that fits. If quality alone cannot reach the target, and you leave its option on, it also reduces the pixel size a little. Untick that if you need the original dimensions. It can’t go below 10 KB, and a photo that must be tiny may need a resize first.

Check before you upload

• Look at the size of the exact file you will upload. Names can look alike, and the original is often sitting next to the compressed copy.
• Open the compressed photo and zoom in. Faces and text should still be readable. If they are not, ask for a larger target or use a smaller pixel size.
• If the form still refuses, check the format and any pixel or dimension rule. A correct size with the wrong format is rejected just the same.

A side benefit: a photo drawn fresh by the compressor carries no location or camera notes, so it is also tidier to share. The original stays unchanged on your device.

If the photo is an ID or passport page, see how to store ID and passport scans safely once the form is done.