How to reduce an image to a target file size for an online form

A practical explanation of dimensions, format and quality when a website asks for a photo under a particular file-size limit.

Start with the required dimensions

If a form specifies both pixel dimensions and a maximum file size, satisfy the dimensions first. Resizing an unnecessarily large image before compression usually makes the final file easier to control.

Choose the right format

JPEG is generally useful for photographs because it can achieve a much smaller file than an uncompressed image. PNG is useful for graphics and transparency, but a photographic PNG can be much larger.

Adjust quality gradually

Compression quality is a trade-off. Start with a reasonably high setting and reduce it until the file fits the requirement while remaining readable. Avoid repeatedly opening and re-saving JPEGs because each lossy save can remove additional detail.

Use the FormWise image tools

The Image Resizer can set exact pixel dimensions, while the Image Compressor can create a smaller JPEG directly in your browser.