Read the form carefully
Forms usually ask for two things: dimensions in pixels (for example 600 × 600 or 413 × 531) and a maximum file size in KB. You must meet both.
Step 1: set the pixel size
Open the resize tool and type the exact width and height. Common sizes: 413×531 (35×45 mm photo), 600×600 (square photo), 1000×1000 and 1280×720.
Step 2: reduce the KB
Then use the 50KB, 20KB or custom size tool to fit the file limit.
Step 3: check the format
Most forms want JPG. If you have a PNG or WebP, convert it with the image converter first.
Common mistakes
Stretching a picture to the wrong shape, compressing before resizing, and uploading a file that is slightly over the limit. Aim just under the limit.