How to check an image's file size
- Add your images with Select files or drag and drop. Several at once is fine.
- Read each file's size in bytes, KB and MB, along with its pixel dimensions.
- Set the size limit from your upload form to see which files exceed it.
- Shrink oversized files with Compress Image to KB or the Image Compressor.
Why the numbers sometimes differ
Kilobytes are counted in two ways. In decimal units 1 KB is 1,000 bytes; in binary units, which Windows uses, 1 KB means 1,024 bytes. A 51,000-byte image is 51 KB by one convention and 49.8 KB by the other, which can decide whether an upload is accepted. The checker shows the exact byte count so you can compare against whichever rule a website uses.
Checking against an upload limit
Application portals, job sites and email services often cap attachments, for instance a 50 KB photo, a 20 KB signature or a 2 MB document image. Entering the limit highlights every file that is too large, so you can fix them before you start filling in the form. Checking every file first is especially useful for forms that ask for several images, such as a photo, a signature and a thumb impression.
What determines image file size
File size depends on the number of pixels, the format, the compression quality and how detailed the picture is. A busy photo compresses less than a plain background. Embedded metadata such as camera data and preview thumbnails can add tens of kilobytes, which Remove EXIF Data strips without touching the image itself.
Frequently asked questions
Is 1 KB equal to 1,000 or 1,024 bytes?
Both are used. Decimal KB is 1,000 bytes; Windows and many older systems use 1,024 bytes.
Why does my computer show a different size?
Your file manager may round values or use binary units. The exact byte count shown here is the precise size.
How can I make an image smaller?
Compress it, reduce its dimensions or convert it to a more efficient format such as JPG or WebP.
Are my files uploaded?
No. Sizes are read locally in your browser.