Image Resizer to KB – Compress or Increase Image Size
Just type the size in KB. The tool makes your photo smaller, or exactly that big. Nothing is uploaded.
Advanced (optional): exact pixels or minimum KB
Many forms ask for pixels as well as KB. Leave empty if yours does not. Examples are common sizes only – always use the size your form states.
✅ Done! Your images are ready
Type the number your form gives you
Percentage sliders do not help when a form says “at most 50KB”, because you cannot tell what size you will get. This page works the other way round: you type the number from the form, choose Compress or Increase and press the button. The tool then works towards that exact size.
Which mode do I need? Read the wording on your form
- “Up to”, “maximum”, “not more than”, “less than” → Compress.
- “At least”, “minimum”, “not less than” → Increase.
- “Between 10 and 20KB” → Compress to 20 and set Minimum KB to 10 under Advanced.
- A size in pixels as well → enter width and height under Advanced and choose crop, white borders or stretch.
How the number is counted
Computers often use 1MB = 1,024KB, but many websites count in 1,000-byte units. To avoid a surprise rejection, Compress mode stays under your number counted the smaller way, so the file passes under either method. Increase mode pads to exactly your KB counted as 1,024 bytes, which is never smaller than the other way of counting.
For the plain quality-percentage compressor and bulk ZIP downloads, use the homepage compressor.
Pick a ready-made size page
Compress image to a smaller size
Increase image size to a larger size
Signature, passport photo, formats and more
Resizer questions
What is the difference between Compress and Increase?
Compress makes a large file smaller by lowering JPG quality and, when needed, pixel dimensions. Increase takes a small file and adds invisible padding so it reaches an exact size, without changing how the picture looks.
What does the Minimum KB box do?
It is for ranges such as 10–20KB. Type 20 as the size and 10 as the minimum. If the compressed file would be smaller than 10KB, the tool pads it up so it lands inside the range.
Why is my result smaller than the number I typed?
Compress mode keeps the best quality that stays under your limit, so the file can come out a little below it. If your JPG was already under the limit, it is returned unchanged.
What happens if the file cannot be made small enough?
For extremely low limits the tool shrinks the pixel size as far as it sensibly can and then reports that it could not fit. Try a larger limit or crop the picture first.
Which formats can I use?
JPG, PNG, WebP and iPhone HEIC photos go in. Whatever you choose, the result is a standard JPG.
Want a quality percentage instead? Use the image compressor.
About the Image Resizer to KB tool
This is the main resizer. Type any size in KB, pick Compress to make an image smaller or Increase to make it larger, and download the result. The pages below are ready-made versions of the same tool for common sizes.
How to use the Image Resizer to KB tool
- Tap “Select Images” and choose your JPG, PNG, WebP or HEIC file.
- Choose Compress to make it smaller or Increase to make it bigger.
- Type the KB value from your form, or tap one of the quick sizes.
- Press the green button, check the Before and After sizes, then download the file or the ZIP.
More questions about Image Resizer to KB
Which size page should I choose?
Pick the one that matches the limit on your form. If yours is not listed, type your own number here.
Do the size pages use different tools?
No. They all use the same resizer. A size page just fills in the number for you.