To compress an image, drop your JPG, PNG or WebP files into the box above and choose how: by Quality (default 75, with an optional max width) or by Target size, where you enter a size in KB such as 100 or 50. Click Compress to see the before and after size of each file, then download the results individually or as a ZIP.
How to use the Compress Image tool
- 1
Add your images
Drop JPG, PNG or WebP files in or click to select them — up to 50 per run, each up to 50 MB.
- 2
Choose Quality or Target size
Under Compress by, pick Quality to set a value from 10 to 100 (default 75) and an optional max width, or Target size to enter a size in KB — presets are 20, 50, 100, 200 and 500 KB. JPG and WebP keep their format; in Quality mode PNGs can be saved as WebP (default), JPG or PNG.
- 3
Compress
Click Compress. Each file is processed in your browser and shown with its original size, new size and percentage saved; in Target size mode you also see the final pixel dimensions and the quality used.
- 4
Download
Download files one by one or all together as a ZIP. Files that could not be made smaller are kept as the original.
Compress image to 100KB, 50KB or 20KB
Online forms, job and exam portals, and email services often set an upload limit in kilobytes. For those, switch Compress by to Target size, type the limit in KB or tap one of the presets (20, 50, 100, 200 or 500 KB) and click Compress. Any number works, so a 75 KB or 300 KB limit is fine too.
Behind the scenes, the tool binary-searches the encoder quality at full resolution: it tries a quality, checks the resulting size, narrows the range and repeats until the file is at or under your target. If even the lowest quality is still too big, it shrinks the width and height in 15% steps and searches again until the file fits.
JPG stays JPG and WebP stays WebP. A PNG becomes WebP, or JPG if your browser cannot encode WebP, because a lossless PNG cannot be forced down to an arbitrary size. Images already under the target are kept unchanged. Each result shows the final size, pixel dimensions and quality used. Very small targets, such as 20 KB for a 12-megapixel phone photo, are reached by reducing dimensions, so the image also gets smaller in pixels.
Quality mode: how the slider trades size for detail
Lossy formats like JPG and WebP shrink images by discarding detail that is hard to see. The quality slider controls how aggressive that is. At high values, the image looks almost identical to the original but the saving is modest. As you lower the value, files get smaller and artefacts slowly appear: blockiness in smooth areas, smearing in fine textures and halos around sharp edges.
The default of 75 is a practical middle ground for photos shown on screens. For images that will be printed or examined closely, stay higher. For thumbnails or images where small file size matters most, you can go lower, but check the result before using it. Faces, skies and text inside photos are the first places artefacts become noticeable.
How to compress PNG files, and why they become WebP
PNG is lossless, which means there is no quality knob to turn: every pixel has to be kept. Re-saving a PNG as PNG rarely makes it much smaller. To get real lossy compression, the image has to change format, which is why the tool switches PNG files to WebP by default. To compress JPEG photos, no format change is needed: they simply stay JPG at a lower quality.
WebP keeps transparency, so logos and cut-outs still work, and it is supported by all current major browsers. If you need maximum compatibility and the image has no transparency, choose JPG instead. If the file must stay PNG, for example because a system requires it, you can keep PNG, but expect a much smaller saving.
Often the biggest saving has nothing to do with quality: it comes from pixel dimensions. A photo straight from a phone camera is far wider than most screens and layouts need. Setting a max width, such as the width at which the image will actually be displayed, shrinks larger images while keeping their aspect ratio, and leaves images that are already smaller untouched.
Before and after sizes, without sending files out
Every file shows its original size, compressed size and percentage saved, so you can judge the trade-off image by image. If compression would make a file larger, which can happen with images that are already well optimised, the tool keeps the original and marks it as already optimized instead of handing you a worse file.
All of this happens in your browser. The images you compress, whether they are product photos, scanned documents or pictures for a job application, are never uploaded to Krawly's servers and are not stored. There is no signup, no watermark and no daily limit.
Tips for the best results
- Facing a strict upload limit? Use Target size instead of guessing a quality value.
- Set a max width matching where the image will be displayed — it often saves more than lowering quality.
- Start with the default quality of 75 and compare the result before going lower.
- Choose JPG output for PNG photos without transparency when compatibility matters more than size.
- Look at faces, skies and text at full size to spot compression artefacts.
- Don't recompress the same image repeatedly; always start from the original file.
Frequently asked questions
How do I compress an image to 50KB?
Choose Target size under Compress by, tap the 50 KB preset or type 50, and click Compress. The tool lowers the quality first and, only if that is not enough, reduces the dimensions in 15% steps until the file is 50 KB or less. In this mode PNGs are saved as WebP, or JPG if WebP is unavailable.
How do I reduce image size in KB?
Use Target size mode and enter the limit in kilobytes. 20, 50, 100, 200 and 500 KB are one-tap presets, and any other number works too. If you would rather control the look directly, use Quality mode with a max width instead; the before and after sizes show exactly how many KB you saved.
Can I compress an image without losing quality?
Not completely, because lossy compression always discards some detail. In practice a moderate setting such as the default 75, plus a max width close to the display size, gives much smaller files that look the same on screen. Reducing oversized dimensions often saves more space than lowering quality.
Why was my PNG converted to WebP?
PNG is lossless, so it cannot be compressed much while staying PNG. WebP offers lossy compression and still supports transparency, so it is the default output for PNG files. In Quality mode you can choose JPG or keep PNG instead; in Target size mode a PNG always becomes WebP, or JPG if your browser cannot encode WebP.
What does 'already optimized' mean?
It means the compressed version would have been larger than your original file. In that case the tool keeps the original rather than giving you a bigger file. This can happen with images that were already heavily compressed.
Does compressing an image change its dimensions?
In Quality mode, only if you set a max width: wider images are scaled down with their aspect ratio kept, and narrower ones keep their size. In Target size mode, dimensions are reduced in 15% steps only when even the lowest quality cannot reach the target; the result shows the final pixel size.
Are my images uploaded to a server?
No. Compression runs entirely in your browser, including the before and after size comparison. Your images are never uploaded to Krawly's servers and nothing is stored after you close the tab.
Which formats can I compress?
You can compress JPEG (JPG), PNG and WebP images. JPG and WebP files are saved in the same format by default; PNG files are saved as WebP by default, with JPG or PNG available as alternatives.
Private by design. Every Krawly converter runs inside your browser using JavaScript and WebAssembly. Your files are not uploaded, stored or seen by anyone — when you close the tab, they are gone.