Increase File Size in KB Online — Free Browser Tool
This free tool increases a file to any size you need — 20KB, 100KB, 2MB or a figure you type — by padding it with invisible data that leaves the image untouched. Everything runs in your browser, so nothing is uploaded.
Increase JPG, PNG or PDF file size
Runs entirely in this browser tab. Your file is never uploaded.
Drag a JPG, PNG or PDF file here, or
Nothing is uploaded when you pick a file.
How it works
- 1
Choose your file
Drag a file onto the tool above or click to browse. It accepts JPG, PNG and PDF files, and the file is read directly by your browser rather than sent anywhere.
- 2
Set your target size
Pick a preset from the dropdown or type an exact figure in KB or MB. The output will match that number byte for byte.
- 3
Choose how the size is added
The default pads the file with metadata areas that the file format reserves for data decoders ignore, so the image is untouched. Switch to "increase resolution" if you want more pixels as well as more bytes.
- 4
Download the result
Press the button and your browser saves the new file at exactly the size you asked for. Nothing was uploaded, so there is nothing stored anywhere for you to delete afterwards.
When you would need a bigger file
Plenty of upload forms set a minimum file size as well as a maximum, and reject anything under it. Government portals, visa and examination sites are the usual culprits. A perfectly clear scan that happens to compress well fails the check with no explanation of what is wrong.
The minimum exists to screen out unreadable scans, but it cannot tell an unreadable file from an efficiently compressed one. Padding the file to the size the form wants gets you past the validator without touching a single pixel of the image.
Frequently asked questions
Will this reduce my image’s quality?
No, and that is the point of doing it this way. Adding bytes to metadata areas that the file format reserves for data decoders ignore changes the file’s size without touching the part of it that describes the picture, so there is no mechanism by which the quality could drop.
Is my file uploaded to a server?
No. The entire process runs in your browser using the File and Canvas APIs and pdf-lib. Your file is read from your own disk, changed in memory and handed straight back to you. You can confirm it by opening your browser’s Network tab while you use the tool — there is no upload request, because there is no upload endpoint.
What file formats are supported?
JPG (including .jpeg), PNG and PDF. Each one is padded using the structure its own specification reserves for data readers can ignore, so the output is always a valid file of that type.
Why would I need to increase file size instead of decrease it?
It is rarely a want, usually a requirement. A portal has refused the file for being below its minimum, the scan itself is fine, and rescanning it at a higher DPI means finding the document and the scanner again. Padding gets the number where it needs to be in seconds.
Is this free to use?
Yes — free, with no account, no watermark, no email address and no limit on how many files you run through it. Because the work happens on your own device rather than on a server, there are no processing costs to pass on.