Resize an image when its pixel width or height is too large for the destination. Compress it when the dimensions are acceptable but the file’s byte size is too large. Some workflows need both steps, but changing one does not guarantee a particular result for the other.
Check what the upload actually limits
Look for a stated maximum pixel dimension, file size, file format or combination of requirements. If a service rejects an image because its dimensions exceed a limit, reducing quality alone may leave those dimensions unchanged. If only the byte limit is exceeded, resizing may help, but it may reduce detail more than necessary.
For a pixel limit, use the Bulk Image Resizer and choose whether the image should fit inside a box or fill it with a crop. For a file-size problem, use the Image Compressor to adjust compression or output format. Follow the destination’s own instructions; there is no universal upload limit.
When both dimensions and file size matter
First resize to a suitable maximum dimension, then compress the result if its file size still exceeds the stated limit. Save a copy of the original. After export, check the new width and height as well as the file size, then inspect the image at its expected display size for visible artifacts, softened text or lost transparency.
Compression behavior depends on the source image and format. A lower quality setting may reduce detail; converting formats can also change transparency or appearance. Keep an original copy so you can adjust the result without repeatedly recompressing an already compressed file.
Use the right tool for the next step
Choose the resizer for pixel geometry, the compressor for encoded file size, or both in sequence when the destination sets both limits. Then upload the exported copy and confirm that it meets the receiving service’s current requirements.
Explore related tools in Image Tools.