Photo for documents under 100 KB: pixels and kilobytes explained
Many portals ask for a photo of a certain size in pixels and a file of no more than a given number of kilobytes, often 100 KB or less. These are two separate requirements, and mixing them up is a common reason for a rejected upload.
Pixels and kilobytes are different things
Pixels describe the dimensions of the picture, for example width by height. Kilobytes describe how much space the file takes. You can have a small picture with a large file, or a large picture with a small file, depending on the compression. The official requirements of the service you apply to always come first, because they differ between countries and organisations.
What decides the file size
- Dimensions: more pixels mean more data.
- JPG quality: lower quality means a smaller file, but too low gives visible blocks.
- Detail and noise: a plain background and even light compress much better than a busy scene or a dark, grainy photo.
Take a good source photo
- Stand in front of a plain, light wall in soft daylight, without harsh shadows on the face.
- Keep the camera at eye level and look straight into it.
- Do not use filters, beauty modes or heavy retouching.
- Take the picture at a reasonable distance rather than zooming in digitally.
How to fit the limit
- Open Photo size in KB and add your picture.
- Choose the required size in pixels.
- Set the maximum size in KB.
- Move and zoom the crop so the face sits as the requirements describe.
- Download the JPG and check that it still looks sharp.
Common mistakes
- Renaming a PNG file to .jpg does not convert it. Use a real converter.
- Taking a screenshot of a photo lowers its quality.
- Squeezing the picture to a different proportion makes faces look stretched.
- Compressing the same JPG again and again keeps degrading it. Always start from the original.
If your photo is a HEIC file from an iPhone, convert it first with HEIC to JPG. Everything is done in your browser, so your face photo is not sent anywhere.