Increase the size of an image in KB
Some upload forms reject a photo for being too small: "file must be at least 50 KB". Enter the minimum and this page brings your image up to it.
- Runs in your browser
- Nothing is uploaded
- No sign-up
- Batch up to 20 images
Drag & drop your image here
or tap to browse · you can also paste from the clipboard
JPG · PNG · WebP · GIF · BMP · AVIF · SVG · up to 50 MB each · up to 20 files
Choose imagesBefore
After
Processed image will appear here.
How to use the image size increaser
Add your image and type the minimum size the form asks for. The file is saved at the highest JPG quality that fits, enlarged only if that is not enough, and topped up with padding so it reaches the size you typed. The picture itself looks the same.
- Add your imageThe photo or signature the form refused.
- Enter the minimum sizeType the lower limit from the form, in KB or MB.
- DownloadThe file is at the minimum, with the quality, scale and padding listed.
About this tool
Application forms often give a range, such as 20 KB to 50 KB for a photograph or 10 KB to 20 KB for a signature. A small, tightly compressed image falls under the lower limit and is refused, even though nothing is wrong with the picture.
A file can be made larger in three ways, and this page uses them in order. First it saves the picture at a higher quality, which can make a JPG several times bigger. If maximum quality is not enough, it enlarges the pixel dimensions. Any gap that is left is filled with padding, which is spare data inside the file that does not show in the picture. The result panel says which steps were used. None of them adds detail: the photo looks the same, it just takes more bytes.
What you get
- Normally lands on the minimum you type, not somewhere above it
- Raises JPG quality first and enlarges only if needed
- Padding-only mode that leaves the picture untouched
- Reports exactly how the size was reached
- Batch up to 20 files against the same minimum
When to use the image size increaser
A photo under the form's lower limit
Exam and recruitment portals that accept a photograph of 20 KB to 50 KB refuse a neat 12 KB file. Raising it to 20 KB or a little more gets it through.
A signature scan that is too small
A signature is mostly blank paper and compresses to a few kilobytes, below the 10 KB floor many forms set.
A document image read as low quality
Some systems treat a very small file as an unreadable scan. Bringing it over their threshold avoids the automatic rejection.
A picture shrunk by a messaging app
Photos forwarded through chat apps come back heavily compressed. This will not restore them, but it will meet a size rule when the original is gone.
Which method to choose
| Situation | Method | What happens to the picture |
|---|---|---|
| JPG photo a little under the minimum | Raise quality | Saved again at a higher quality; pixel size unchanged |
| JPG photo far under the minimum | Raise quality, with enlarging on | Saved at maximum quality and enlarged |
| The pixel size is fixed by the form | Raise quality, with enlarging off | Pixel size unchanged; padding covers any gap |
| The picture must not be altered at all | Padding only | Copied byte for byte, with filler added |
| PNG image | Either | PNG has no quality setting, so it is enlarged or padded |
How it works
The work is done in a fixed order. The picture is first encoded at maximum quality. If that is already over the minimum, a search of up to eight quality settings finds the highest one that stays under it. If maximum quality is still too small, the picture is enlarged, to at most six times its width or 16 megapixels, and the enlargement is narrowed down until the file at maximum quality sits just under the minimum. Whatever gap remains is closed with padding, so the file ends on the minimum or within a few bytes above it.
Padding is written as a comment: a COM segment in a JPG, or a text chunk in a PNG. Both are standard parts of the format, intended for notes, and decoders skip them when drawing the picture. The comment starts with a sentence saying what it is and is filled out with spaces. A minimum is counted as 1,024 bytes to the kilobyte, the larger of the two definitions in use, so a file made for a 50 KB minimum is 51,200 bytes and also passes a form that counts 1,000.
Common problems and how to fix them
- The form now says the file is too large
- The form has an upper limit too, and the figure you entered is above it. Enter a value just over the lower limit instead; the result lands on the number you type.
- The result is well above the minimum I typed
- That happens when the picture cannot be stored that small in the chosen format, for example a detailed WebP or PNG being saved as JPG. The file still meets the minimum. If it must sit inside a narrow range, bring it back down with the Image File Size Reducer.
- The uploaded file shrank again
- The site re-compresses uploads, which discards padding and resets the quality. Leave enlarging on and use the Raise quality method, so more of the size comes from the image itself.
- The picture looks slightly soft
- It was enlarged to reach the size. Turn off "Enlarge the image if needed" to keep the original pixels and let padding make up the difference.
Frequently asked questions
How do I increase the size of a photo in KB?
Add the photo, type the minimum the form asks for and download. The picture is saved at the highest quality that fits and topped up to that size, so a 15 KB photo given a 50 KB minimum comes back at 50 KB.
Does a larger file mean better quality?
No. Saving at a higher quality setting keeps what is there and stops further loss, but it cannot bring back detail that earlier compression removed. The picture will look the same. This page is for meeting a size rule, not for improving a photo.
The form wants between 20 KB and 50 KB. What should I enter?
Enter 20, or a little more, such as 25, to stay clear of the edge. The result lands on the figure you type, well inside the range. If your file is over the upper limit instead, use Compress Image to 50KB.
What is padding, and is it safe?
Padding is filler text stored in a comment field that the JPG and PNG formats provide for notes. Image viewers skip it, so the picture is displayed exactly as before. Be aware that a site which re-compresses uploads, or a tool that strips metadata, will remove it again.
Can I increase a JPG from 10 KB to 50 KB?
Yes. Enter 50 as the minimum. A 10 KB JPG is small or heavily compressed, so expect maximum quality plus some enlargement or padding. The result panel lists exactly what was used.
Does it change the dimensions of my image?
Only when a higher quality alone cannot reach the minimum and enlarging is switched on. The new pixel size is shown with the result. Switch enlarging off, or use Padding only, to keep the dimensions fixed.
Which formats can be made larger?
The output is JPG or PNG. Other formats, such as WebP or GIF, are saved as JPG first. A PNG has no quality setting to raise, so it is enlarged or padded instead.