File size (KB) is not the same as dimensions (pixels)#

File size is how much storage the file takes; dimensions are the number of pixels across and down. A 300×400 photo can be 40 KB or 200 KB depending on the format and the quality it was saved at. On the other hand, a 4000×3000 phone photo can be squeezed to 100 KB, but only by lowering the quality or the dimensions. That is why many forms set both limits: "maximum 100 KB, 300×400 pixels".

In this tool, set the dimensions first and then the target size. The tool finds the highest quality that stays under that size. If quality alone is not enough and you did not ask for exact pixels, it also scales the image down a little, so the photo gets smaller instead of blocky.

How upload forms check the size#

Most sites read the file size in bytes and compare it with a number such as 100 KB. The catch: some count a kilobyte as 1024 bytes, others as 1000. This tool keeps the file just under the thousands figure (for 100 KB, under 100,000 bytes), so it passes either way. That is why Windows may show it as about 97 KB.

Some portals only accept the .jpg or .jpeg extension, and some check the pixel size exactly, so read the form's instructions carefully. If the form also has a minimum (for example between 50 and 100 KB), use the larger number as your target.

Which format should I choose?#

  • JPG: the safest choice for government, university and bank forms, and the best format for photos.
  • WebP: usually 25–35% smaller at the same quality and great for websites and messengers, but many forms still reject it.
  • Same format: keeps PNG as PNG. PNG is lossless and suits screenshots and logos, but its size only drops when you reduce the dimensions.

For ordinary photos, convert PNG to JPG. Transparent areas are filled with the background colour you pick; white works best for ID photos.

Privacy: your photo goes nowhere#

Everything runs inside your browser and no image is sent to a server — you can even go offline once the page has loaded. Phone photos usually carry EXIF data: the phone model, the time the photo was taken and often the exact GPS coordinates of where it was taken. The files this tool produces contain none of that, so they are safer to share. Rotation is applied before the data is dropped, so the photo does not end up sideways.

Tips for better results#

  • For an ID photo, tap the 300×400 ID photo button; extra edges are cropped from the centre and the face is never stretched.
  • If text in a scanned document becomes hard to read, lower the dimensions or raise the target instead of lowering the quality.
  • Most Windows and Android browsers cannot open iPhone HEIC photos; convert them to JPG first.
  • In Compare, drag the middle line and switch to Actual size to see fine detail.