Resize Image to KB Online
Get a photo under an upload limit like 50 KB, 100 KB or 200 KB. Choose the limit, and the tool finds the highest quality that fits — reducing dimensions only if it has to.
Free to use · No signup · No watermark
Drop your image here
or click to upload — JPG, PNG and WebP supported
Your image is compressed in your browser and never uploaded.
What Does It Mean to Resize an Image to KB?
Resizing an image to KB means reducing the size of the file, not necessarily the size of the picture. Those are two different measurements, and upload forms usually care about the first one.
Dimensions describe how many pixels wide and tall an image is. File size describes how much storage it takes up. Changing one does not automatically change the other in a predictable way.
You will also see this written as resizing an image in KB, reducing photo size in KB, or compressing an image to KB. They all describe the same job: getting the file under a limit measured in kilobytes.
This tool works on compression first, because that leaves your image at its original dimensions. It only reduces the width and height when compression alone cannot reach the target you asked for.
Read the requirement carefully: a limit written as 100 KB is about the file, while one written as 600 × 600 is about the picture. If you were given pixel dimensions, use the Image Stretcher instead.
Image dimensions
1200 × 800 px
How many pixels wide and tall the picture is. Change this with the image stretcher.
versus
File size
100 KB
How much storage the file takes. This is what an upload limit measures — and what this tool changes.
How to Resize an Image to a Specific KB Size
- 1
Upload Your Image
Choose a JPG, PNG, or WebP image from your device, drag it onto the upload area, or paste it straight from your clipboard.
- 2
Choose Your Target Size
Select a popular preset or enter the exact KB limit you need. If you have been given a specific maximum, type that number.
- 3
Resize and Download
The tool optimizes the image, shows you the final size next to your target, and prepares it for download.
Choose a Popular Image Size
The limits people are asked for most often. Each one opens the tool with that size already selected, plus advice for getting the best result at that size.
- 20 KBFor extremely small upload limits, usually on older forms.Resize to 20 KB
- 50 KBFor strict file-size requirements where anything larger is rejected.Resize to 50 KB
- 100 KBA common small image limit, and the default most portals ask for.Resize to 100 KB
- 200 KBA balance between a small file and keeping visible detail.Resize to 200 KB
- 300 KBFor medium-size uploads that still need to stay light.Resize to 300 KB
- 500 KBFor larger images where more visual detail matters.Resize to 500 KB
- 1 MBFor uploads that allow a full megabyte of headroom.Resize to 1 MB
What Affects Your Image File Size?
Image format
JPEG throws away detail the eye is least likely to miss, which makes it small and well suited to photographs. PNG is lossless and keeps transparency, so it is usually much larger. WebP generally lands smaller than JPEG at a similar quality, when the browser can write it.
Image dimensions
A larger image holds more pixel data, and more data takes more storage. Halving both the width and height leaves a quarter of the pixels, which is why reducing dimensions is such an effective last resort.
Compression level
Higher compression means a smaller file and more visible artefacts — soft edges, blocky patches, banding in skies. The useful setting is the highest quality that still meets your limit, which is what this tool searches for.
Image content
A detailed photograph of foliage compresses far less than a flat logo or a screenshot of text. Two images with identical dimensions and settings can end up very different sizes for this reason alone.
How to Reduce Image Size Without Unnecessary Quality Loss
- Start with the size you actually need. If a form allows 500 KB, there is nothing to gain from forcing the file down to 50 KB.
- Work from the original file where you can. Compressing an image that has already been compressed several times stacks the damage.
- Use JPEG or WebP for photographs. Both have a quality setting, which is what lets a target be met without touching the dimensions.
- Keep PNG for graphics with flat colour or transparency — but expect it to need smaller dimensions to reach a tight limit, since it has no quality setting to trade.
- Remember that very large dimensions make very small targets harder. A 6000-pixel-wide photo squeezed into 20 KB will have to lose dimensions as well as quality.
Frequently asked questions
How do I resize an image to a specific KB size?
Upload a JPG, PNG or WebP image, choose a target size — either a preset or your own number in KB — and select Resize Image.
The tool compresses the image until it fits under that limit, then shows you the final size so you can download it.
Can I resize an image to exactly 100 KB?
Not to the exact byte. Image encoders take a quality setting, not a file size, and how many bytes a given quality produces depends on the picture itself.
What this tool does is search for the highest quality that still lands under your target, so a 100 KB limit typically produces a file in the high nineties. It never knowingly hands you a file over the limit you set.
Can I resize a PNG image to KB?
Yes, though PNG behaves differently. It is lossless and has no quality setting, so the only way a PNG can get smaller is by reducing its dimensions.
If the image has no transparency, converting it to JPEG or WebP will usually hit a small target while keeping the original width and height. Choose the format under the target size controls.
Will reducing an image to KB reduce its quality?
Usually, yes — compressing a photo discards some detail, and the smaller the target, the more is lost.
Because the tool keeps the highest quality that still meets your limit, it helps preserve as much visual quality as the target allows. Setting a target only as small as you actually need gives the best result.
Can I resize an image to 50 KB or 200 KB?
Yes. Both are available as presets, along with 20 KB, 100 KB, 300 KB, 500 KB and 1 MB, and you can type any value in between.
Very small targets on a large, detailed photo may need the dimensions reduced as well. The tool does that proportionally and tells you when it happened.
Why is my image still over the limit?
Some images can't get that small in the chosen format. The tool lowers quality first, then reduces dimensions down to a floor it won't go below, and if the file is still too big it says so and shows the closest result instead of pretending it worked.
Try a larger target, or switch to JPEG — a PNG can only shrink by losing pixels, so it struggles with small limits.
Will a transparent PNG keep its transparency?
With Auto selected, yes where your browser can write WebP: the image is saved as WebP, which keeps transparency and still has a quality setting. Otherwise it stays PNG.
Choosing JPEG fills transparent areas with a solid background, because JPEG has no transparency.
Are my uploaded images stored?
No. The image is read, compressed and saved entirely by your own browser. Nothing is uploaded to a server and nothing is kept after you close the tab.