Pixels or kilobytes?
Know what to change.

Separate the requirements

A form might ask for a JPEG that is 300 × 400 pixels and below 200 KB. That is three requirements: format, dimensions and file size. Meeting one does not guarantee the other two.

Pixels describe the image grid: width first, then height. KB and MB describe how many bytes the file occupies. A photo with fine texture can take more bytes than a plain graphic with the same dimensions, because their pixels encode differently.

Crop for shape, resize for dimensions

Cropping removes part of the scene. Resizing scales the part you kept. If a landscape photograph needs to become a 3:4 portrait, start by cropping to the 3:4 ratio. Then resize it to the required pixel dimensions with the aspect ratio locked.

In this example both sides are halved, so the pixel count becomes one quarter. The file’s KB size does not necessarily become one quarter, because format, quality and image content also affect it.

Forcing unrelated width and height values stretches the subject. If the required ratio differs from the source, crop first instead. Enlarging a small image creates more pixels, but does not recover details that were missing from the original.

Choose the format for the job

JPEG / JPG

Useful for photographs when accepted. It uses lossy compression and does not support transparency; transparent areas are filled with a background colour.

PNG

Useful for transparent marks and crisp graphics. It preserves the encoded pixels losslessly, but can be large for photographs.

WebP

Supports compact images and transparency. Check the receiving website’s accepted formats before using it.

Renaming a file extension is not conversion. Export through the format selector so the file’s contents match its extension. Converting an already blurred JPEG to PNG cannot restore the missing detail.

A practical order for a photo upload

1. Read the required format, aspect ratio, dimensions and byte limit.
2. Use Crop image to keep the subject and any required margin.
3. Use Resize image to set the final dimensions without stretching.
4. Use Compress image to choose the accepted format and a maximum file size.
5. Prepare and download the result. Check its dimensions, size and visible detail before submitting it.

You can also do these adjustments together in Image Studio. For the example requirement of 300 × 400 pixels and under 200 KB, a 3:4 crop followed by a locked resize gives the dimensions. A JPEG export with a 200 KB maximum addresses the byte limit separately. These are example values, not official photo rules.

If the portal still rejects it

Check the file you actually downloaded, rather than the original you opened. Confirm that you selected an accepted format and did not submit a ZIP when the portal expects an image. Check any filename restrictions and whether both width and height meet the requirement.

A maximum is a ceiling rather than an exact target. A result may be smaller, and some targets cannot be met at the current dimensions. Docifer’s image limit uses 1,024 bytes per KB; a website may count differently. Leave some room below a strict limit if needed.

Keep a transparent signature as PNG unless the recipient explicitly requires something else. If a document needs preparation rather than an image upload, the document editor may be the more appropriate starting point.