Edited by Tejas Telkar · Published · Updated
Short answer
NotchPop's Files tool can convert an image at its original size or cap its longest dimension at 1024, 2048 or 4096 pixels. Choose the output format separately. Smaller dimensions and lower lossy quality can change file size, but no exact upload-size target is guaranteed.
Read the destination's actual constraint
A site asking for an image under a certain number of megabytes is imposing a file-size limit. A site asking for a maximum width is imposing a dimension limit. They are related but different: two pictures with identical dimensions can have very different file sizes because their detail, format and quality settings differ.
Keep a full-size original before preparing an upload copy. A small thumbnail cannot later supply the detail of the original. If you need an exact crop, aspect ratio or print layout, prepare that in an image editor; a maximum-dimension setting is not a crop tool.
Choose dimensions and format independently
- Open Files in NotchPop and select the source image.
- Choose JPEG, PNG, HEIC or PDF for the destination's format requirement.
- Open Image size and choose Original or an available maximum: 1024, 2048 or 4096 px.
- For JPEG or HEIC, choose the desired quality. Convert and open the newly created file.
The converter preserves the original and creates a separate output. PNG and PDF use their own lossless-labelled output path; JPEG and HEIC expose a quality control. Use a lower quality only when the resulting appearance still suits the task. A white background is used when transparent pixels are flattened into JPEG.
Check both detail and file size
Inspect text, diagrams and faces at the size the recipient will see. Then check the file's size in Finder and try the destination. If the file is still too large, make one controlled change and compare again. Avoid repeatedly re-encoding an already reduced copy when you can return to the original.
For transparent artwork, the WebP-to-PNG guide explains what to inspect at the edges. For photos rejected because of format alone, HEIC-to-JPG may solve the task without reducing dimensions. Use the file shelf to stage the checked version while leaving the original clearly named in its folder.
Sources and editorial notes
Published by NotchPop, the maker of the app. macOS instructions and third-party claims are linked to the sources below. Settings and offers can change between versions. Read our editorial approach or send a correction.
