Compress an Image to a Target Size in KB
Compress an image to a target size in KB — 100 KB by default, or drag to anything from 10 KB up. Unlike every other tool I checked, this one tells you the quality it settled on, so you can see what hitting that number actually cost.
By Umair Nazir · last checked
Drop an image here
JPG, PNG, WebP or GIF. It never leaves your browser.
Everything runs in your browser. Your image is never uploaded, logged, or stored.
What JPEG Quality Should I Use?I measured the whole curve on three kinds of image. Quality 80 is the elbow for photographs and the wrong answer for screenshots.How to use the Image Compressor
Choose an image
Drop a file in or pick one. JPG, PNG, WebP and GIF all work. Anything over 4096px on its longest side is scaled to that first, which keeps a large camera file within reach of a phone's memory.
Drag to the size you need
The slider starts at 100 KB because that is what most upload forms ask for. Drag it anywhere from 10 KB to 2 MB, or tap one of the presets. If the file you gave it is already small, the target starts lower so you are not asked to make it bigger.
Pick a format
JPEG for photographs, WebP if the destination accepts it since it is meaningfully smaller for the same visible error, PNG when you need transparency or a lossless copy. PNG has no quality setting, so hitting a target there means resizing.
Read what it cost
The results panel shows the new size, the percentage saved, the quality it landed on and the final dimensions. Quality above about 80 is usually indistinguishable from the original; below 60, look closely at edges and flat colour before you use it.
Download
The file is named with the size it came out at, so a folder of them stays sortable. Nothing was uploaded at any point, and closing the tab discards everything.
What a target size actually costs
Every tool that compresses an image to a target size does the same thing underneath: encode, check the size, adjust the quality, encode again, repeat until it fits. This one runs that search nine times and then tells you where it stopped. I checked seven competing tools while building it and not one reports the quality it used, which means a 100 KB file arrives with no way of knowing whether it cost you nothing at all or half the detail in the picture.
It turns out to matter more than I expected. The same 100 KB request lands in completely different places depending on what you give it.
| Image | You ask for | Quality it costs | What that looks like |
|---|---|---|---|
| Photograph | 50 KB | not reachable | Floor is 54.3 KB at quality 30 |
| Photograph | 100 KB | 52 | Visibly softened, usable at small sizes |
| Photograph | 200 KB | 75 | Hard to tell from the original |
| Photograph | 500 KB | 95 | Indistinguishable |
| Screenshot | 100 KB | 99 | Free — the whole file is only 80 KB |
A photograph squeezed to 100 KB comes out at quality 52, which is soft enough to see. The same request on a screenshot lands at quality 99, because that image was never big to begin with. Asked for 50 KB, the photograph cannot get there at all: the floor is 54.3 KB before the picture stops being worth having, so the tool says so rather than returning something unusable and calling it success.
Why it will not go below quality 30
Most tools will happily encode at quality 5 if that is what your target demands. This one stops at 30, and the measurements are the reason. Between quality 100 and 80 a photograph loses two thirds of its file size and gains very little visible error. Between 80 and 30 it loses another quarter and the error nearly doubles. Below 30 you are no longer looking at a smaller version of your photograph, you are looking at a different and worse one.
When quality alone cannot reach the target, the tool scales the image down instead and tells you it did. Fewer pixels at a decent quality beats the same pixels at a terrible one, and the trade is yours to see rather than something done quietly on your behalf.
JPEG, WebP or PNG
WebP is smaller than JPEG at the same visible error, and the gap is not small. On the test photograph, JPEG at quality 90 came to 364 KB with an error of 3.71; WebP reached a very similar 3.89 at 261 KB. Around 28% fewer bytes for the same picture. If the place you are uploading to accepts WebP, use it.
PNG has no quality setting at all. It is lossless, so the only way to make one smaller is to give it fewer pixels. Choose PNG here and the tool resizes rather than pretending a quality slider does something. Worth knowing where PNG wins: on the flat test graphic it came to 21.5 KB against JPEG’s 16.5 KB at full quality, and WebP flattened the same image to 2.9 KB. For screenshots and graphics, WebP is usually the right answer and PNG is the safe one.
One thing PNG does that neither of the others will: keep transparency. If your image has a clear background and you need it to stay clear, JPEG is not an option at any quality.
Nothing is uploaded
Your browser decodes the file, re-encodes it, and hands you the result. No request carries the image anywhere, so there is no copy on a server to log or retain. You do not have to take that on trust: open your browser’s network tab and watch while you compress something.
This is worth stating plainly rather than selling, because it is what most browser-based compressors do and several say so on their own pages. The part that is not standard is the number in the results panel telling you what the compression cost.
Frequently asked questions
How do I compress an image to a target size in KB?
Drop the image in, drag the slider to the size you need, and download the result. The slider starts at 100 KB because that is the limit most upload forms set. Underneath, the tool encodes your image at one quality, measures the file, adjusts and encodes again, repeating nine times to find the highest quality that still fits your target. Then it tells you which quality that was, which is the part most tools leave out.
Why does 100 KB look fine on one image and bad on another?
Because a target size says nothing about what it costs. Measured on 2026-08-30 against a 1200x800 test set: a photograph squeezed to 100 KB lands at quality 52, which is soft enough to notice, while a screenshot asked for the same 100 KB lands at quality 99 because the whole file was only 80 KB to begin with. Photographs carry noise and fine detail in every block, and that is expensive to store. Flat interface colour is nearly free. Same request, completely different price.
Can I compress an image to 50 KB or 20 KB?
Sometimes, and the tool will tell you when it cannot. A 1200x800 photograph bottoms out at 54.3 KB at quality 30, which is the lowest quality worth offering, so a 50 KB target is not reachable at those dimensions without making the image smaller. When that happens the tool scales the picture down and says so, rather than returning something unusable and calling it a success. Screenshots and simple graphics reach 50 KB and below easily.
Is my image uploaded to a server?
No. The file is decoded by your browser, re-encoded by your browser, and handed straight back to you. No network request carries it anywhere, so there is no server copy to log, retain or leak, and closing the tab discards everything. You can confirm this by opening your browser's network tab while compressing. That is worth checking on any tool you use for this, not just this one.
Should I use JPEG or WebP?
WebP if whatever you are uploading to accepts it. Measured on the same test photograph, JPEG at quality 90 came to 364 KB with a root-mean-square error of 3.71 against the original, while WebP reached a near-identical 3.89 at 261 KB. That is roughly 28% fewer bytes for the same visible result. On flat graphics the gap is far wider: 2.9 KB for WebP against 16.5 KB for JPEG and 21.5 KB for PNG. JPEG remains the safe choice for anything that has to be accepted everywhere.
Why can't I compress a PNG below a certain size?
Because PNG is lossless and has no quality parameter to turn down. Passing one does nothing at all, which is why some tools appear to accept a PNG target and then quietly return a file the same size. The only lever PNG offers is fewer pixels, so this tool resizes instead and tells you it did. If you want a small file and do not need transparency, convert to WebP or JPEG.
Does compressing an image again make it worse each time?
Much less than people think, and the reason is worth knowing. I re-saved the same photograph at quality 80 twenty times in a row and the error against the original went from 6.81 to 6.83, which is nothing. Re-encoding at the same quality with the same encoder is close to a no-op, because the data is already quantised onto that quality's grid. What does compound damage is changing something between saves. Resizing the image by 1% between each of ten saves took the error from 6.81 to 12.67 and shrank the file from 238 KB to 127 KB as detail was destroyed.
Does the tool change my image dimensions?
Only when it has to, and it always says so. Quality is the first lever; dimensions are the fallback for when quality alone cannot reach your target. The results panel reports the final width and height, and the scale percentage if it changed. Separately, any image over 4096 pixels on its longest side is scaled to that on load, because a 50-megapixel canvas allocates hundreds of megabytes and stalls a phone.
Is there a limit on file size or number of images?
No account, no daily cap and no watermark. One image at a time, and the practical ceiling is your device's memory rather than a rule: images over 4096 pixels on the longest side are scaled to that first. Everything runs locally, so serving one compression costs the same as serving a thousand.