Resize a passport photo
Set physical size in millimetres and DPI — Image KB Reducer converts to pixels and embeds the DPI in the file.
Questions
Why does DPI matter if the pixel size is already correct?
Printers and photo kiosks read the DPI value embedded in the file, not just the pixel count — Image KB Reducer patches it in so a 413×531 px file also declares itself as 300 DPI, not the ~96 DPI a browser canvas defaults to.
Does this crop my photo?
Yes, centred, and only as much as the aspect ratio requires. A 4:3 phone photo is taller-per-width than 35×45 mm, so Image KB Reducer trims the sides evenly rather than squashing your face to fit. Nothing is ever stretched.
Does it remove the background or check the pose?
No. Image KB Reducer crops, resizes, sets the DPI, and compresses. Background colour, head position, and expression are still yours to get right before uploading.