Upload an image to set its new file size.
Use this free Increase Image Size in KB tool when you need a picture file to reach a specific minimum or exact size. Upload a JPG, PNG, WebP or BMP image, enter the required KB value and download it with the original name and format or choose a new name and format.
The tool is useful for application portals, document systems and upload forms that require an image to be above a certain file-size limit. It works locally in your browser and gives you an exact target option as well as a simple way to add a chosen number of kilobytes.
How to Increase Image Size in KB
- Choose or drag and drop a JPG, PNG, WebP or BMP image.
- Check the original file size and image dimensions shown by the tool.
- Select Set Exact Target if you know the required final size.
- Enter the new image size in KB or choose a quick target preset.
- Use Add More KB when you want to increase the original size by a specific amount.
- Keep the original download name and format or change either option.
- Press Increase Image Size to create the new file.
- Check the generated preview and New File Size, then press Download New Image.
Set an Exact Image Size or Add More KB
Set exact target size
Exact target mode creates an output file with the KB value you enter. For example, choosing 500 KB produces a file containing exactly 512,000 bytes because this tool uses 1 KB as 1,024 bytes. The target must be larger than the uploaded file.
Add a specific number of KB
Add More KB mode calculates the result from the original file size. If an image is 150 KB and you add 100 KB, the new file will be 250 KB. This option is helpful when you only know how much additional file size is needed.
Why Increase an Image File Size?
Most image tools focus on compression, but some websites require a minimum file size. A photo may have the correct dimensions and appearance while still being smaller than the allowed range. Increasing the file size can help meet a portal's validation rule without stretching the image, introducing blur or changing the width and height.
- Meet a minimum KB requirement on an upload form.
- Create a 100 KB, 200 KB, 300 KB or 500 KB image.
- Increase a passport photo or profile picture file size.
- Keep the current resolution while making the file larger.
- Preserve the original format or convert the result to JPG, PNG or WebP.
How the Image Size Increaser Works
When the original format is selected, the tool adds standards-compatible non-visual data to the image container without recompressing its picture pixels. When you select a different format, the image is converted first and then adjusted to the chosen KB target. JPG output uses image metadata segments, PNG uses an ancillary data chunk, WebP uses a container padding chunk and original BMP output updates its file container size.
Supported Image Formats
Increase JPG or JPEG size in KB
JPG is widely used for photographs, scanned documents and online forms. The tool preserves the JPEG picture data and adds valid non-visual segments until the requested target size is reached.
Increase PNG size in KB
PNG is suitable for screenshots, graphics, logos and transparent images. Transparency, color data and original dimensions stay unchanged because the image is not re-encoded.
Increase WebP or BMP file size
WebP and BMP files are also supported. The downloaded file keeps the same extension as the uploaded image, so you do not need to convert the format before increasing its size.
Frequently Asked Questions
How can I increase image size in KB online?
Upload an image, enter a larger target, press Increase Image Size, check the preview and then download the new file.
Can I make an image exactly 100 KB or 500 KB?
Yes. Select Set Exact Target and enter 100, 500 or another custom KB value larger than the original file.
Will increasing KB change the image dimensions?
No. The original pixel width and height remain unchanged.
Does this tool reduce image quality?
No. The image pixels are not recompressed, so the visible picture quality is preserved.
Which image formats are supported?
You can upload JPG, JPEG, PNG, WebP or BMP. The result can keep its original format or be downloaded as JPG, PNG or WebP.
Can I add a specific amount to the current file size?
Yes. Choose Add More KB and enter the amount you want added to the original image.
Are uploaded images sent to a server?
No. Image processing and downloading happen locally inside your browser.
Why did another website change the file size?
Some websites recompress images or remove non-visual data after upload, which can change the file size again.