Increase image size in KB with a free online KB increaser
Enter a minimum file size and see how the result reaches it. More bytes can come from re-encoding, optional upscaling or JPEG comment padding.
Drag images in, paste, or click to choose
A whole folder works too · Ctrl/Cmd+V pastes · on phone this opens your file picker · up to 40 MB per file
How increasing an image's size in KB works
A decodable source already meeting the floor returns unchanged. For a smaller source, the tool searches JPEG quality, then tries optional upscaling, then adds JPEG comment padding if a shortfall remains. The output reports the achieved size and padded byte count. This is a floor, not an exact-size or upper-limit setting.
Where increasing an image's size in KB falls short
- Increasing file size does not reconstruct missing detail. Re-encoding can alter the picture, and padding changes bytes without improving pixels.
- The result can exceed a separate maximum; padding segment overhead can also add a few extra bytes. Check any full upload range yourself.
- Re-encoded output is JPEG. An unchanged source retains its original format and metadata.
Questions about increasing image size in KB
Why does a larger file not necessarily look better?
JPEG re-encoding, upscaling and comment padding can all increase bytes without capturing new detail. Inspect the result if readability or appearance matters.
Will the final size exactly match my target?
No. The tool aims to reach or exceed the floor. Check actual bytes against any separate upper limit.
What is the largest input I can use?
Each input may be up to 40MB, or 41,943,040 bytes, and must be decodable by your browser. Large images and batches can use substantial memory.
Are files sent away to increase their size?
No. The file is processed in your browser tab. Use Download to save the result; refreshing the page clears the loaded files.
