Increase PNG File Quality and Size Free
This free tool re-renders a PNG at a higher pixel resolution and sets it to the exact file size you need. Detail that was thrown away by an earlier compression cannot be recovered, but the file becomes larger and higher-resolution in your browser, with no upload.
Increase PNG file size
Runs entirely in this browser tab. Your file is never uploaded.
Drag a PNG file here, or
Nothing is uploaded when you pick a file.
How it works
- 1
Choose your PNG file
Drag a file onto the tool above or click to browse. It accepts .png 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
Pick padding or a real resolution increase
This page defaults to "increase resolution", which redraws the image at a larger pixel size. Switch to "pad file size" if you only need the byte count to change and want the pixels left exactly as they are.
- 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.
Why a form would reject a file for being too small
The form is not judging your image — it is judging its byte count. That rule was written to stop people uploading unreadable 5KB scans, and it has no way of telling those apart from a clean scan that simply compressed well.
Rescanning at a higher DPI would also clear the threshold, and if your scan really is hard to read that is the better fix. If it is fine and only the number is wrong, padding it is the honest shortcut: the bytes go into extra tEXt metadata chunks, an ancillary PNG block that decoders are required to ignore, and the person who opens the file sees exactly what you scanned.
Why PNG files behave differently
PNG is lossless, so it never throws detail away, but it is built for flat colour: screenshots, logos, diagrams and line art. A signature or a simple graphic can compress to a few kilobytes because a PNG can describe long runs of identical pixels almost for free. Photographs go the other way and stay large.
Padding a PNG adds ancillary tEXt chunks before the file’s IEND marker. Ancillary chunks are the part of the specification that says decoders may ignore what they do not recognise, so the IDAT pixel data is untouched and the image is identical.
Frequently asked questions
Will this reduce my image’s quality?
No. In "increase resolution" mode the image is redrawn at a larger pixel size, so it gains pixels rather than losing them — though enlarging cannot recover detail an earlier compression already discarded. In the default padding mode nothing about the image is altered at all.
Is my file uploaded to a server?
No, and you do not have to take that on trust. Load this page, disconnect from the internet, and use the tool — it still works, which it could not do if your file had to reach a server. Nothing is transmitted, so there is nothing stored and nothing to delete afterwards.
What file formats are supported?
This page is set up for PNG images. The tool also handles PDFs and the other image format — drop any supported file in and it will detect the type from the file itself rather than the extension.
Why would I need to increase file size instead of decrease it?
Because some upload forms enforce a minimum as well as a maximum. The minimum is meant to reject scans too low-quality to read, but it catches efficiently compressed files too. When your file is legible and simply small, making it bigger is the only thing standing between you and a successful submission.
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.