Image Resizer – Resize by Pixels, CM or File Size (KB/MB)
Resize an image online to exact dimensions in pixels, cm, mm or inches, and optionally keep the file under a limit such as 20KB, 50KB, 100KB or 200KB. Free, and nothing is uploaded.
100% client-sideYour files stay in your browser.
- Free, no signup
- px, cm, mm and inches
- Resize to a size in KB or MB
With a size limit the dimensions stay exactly as entered and the quality is chosen automatically. PNG output is switched to JPG, because PNG cannot be shrunk to a size.
How to use Image Resizer
- Drop an image onto the tool, or choose one from your device.
- Pick a unit — pixels, cm, mm or inches — and enter a new width or height. The other side follows while the aspect ratio is locked. Or tap a percentage.
- For cm, mm or inches, choose the DPI. Use 300 DPI for print.
- To resize to a file size, enter a limit such as 20, 50, 100 or 200 KB, or a number in MB, or tap a size.
- Choose PNG, JPG or WebP, click Resize, then download.
Features
- Exact width and height in pixels, centimetres, millimetres or inches
- Resize an image to a file size in KB or MB, such as 20KB, 50KB, 100KB or 200KB
- Aspect ratio lock so images never stretch
- One-tap scale presets: 75%, 50% and 25%
- PNG (lossless), JPG or WebP output
- High-quality downscaling for sharper results
- Processed locally — nothing is uploaded
What can you use the image resizer for?
Most upload forms, ad platforms and social networks expect an image at a specific size, and a picture that is the wrong size gets stretched, cropped or rejected. This image resizer changes the dimensions of a photo and, if you want, also keeps the file under a size limit. Locking the aspect ratio keeps proportions correct, so faces and objects don't distort.
- Fitting a photo to the exact dimensions required by a job application, marketplace or CMS.
- Making a photo a set size in centimetres, for example for a print or an ID-style layout.
- Creating a smaller thumbnail of a larger photo for faster page loads.
- Preparing a profile picture or avatar that meets a platform's square-image requirement.
- Getting an image under 20KB, 50KB, 100KB or 200KB for an upload form.
Image resizer in KB or MB: resize an image to 20KB, 50KB, 100KB or 200KB
Resizing by pixels and resizing by file size are two different things. Pixels set the width and height; kilobytes set how much space the file takes. Enter the dimensions you need, then type a limit under Keep file smaller than, or tap 20 KB, 50 KB, 100 KB, 200 KB, 1 MB or 2 MB. The tool keeps your exact dimensions and lowers the JPG or WebP quality until the file fits. If the limit is too small for those dimensions, it tells you, and you can use smaller dimensions or the Image Compressor, which can reduce both.
Image resizer in cm, mm or inches
A picture has pixels, not centimetres, until it is printed. The printed size depends on the DPI: pixels = inches × DPI. At 300 DPI, a 3.5 × 4.5 cm picture is about 413 × 531 pixels. Choose cm, mm or inches, enter the size you want and the DPI, and the tool works out the pixels. The DPI is not saved inside the downloaded file; it only decides how many pixels are made.
Tips for better results
- Keep aspect ratio locked unless you specifically want to stretch the image — unlocking it can distort faces and straight lines.
- Resize down rather than up where possible; enlarging a small photo makes it blurry since no new detail can be added.
- If a platform asks for an exact size like 1200×630, enter that value directly rather than guessing a scale percentage.
- For the smallest possible file, resize first and then compress.
- Common social sizes to enter directly: Instagram post 1080×1080, Instagram Story 1080×1920, Facebook cover 820×312, YouTube thumbnail 1280×720.
Frequently asked questions
Is the image resizer free?
Yes, resizing images is completely free with no signup required.
How do I resize an image to 20KB, 50KB, 100KB or 200KB (image resizer 200KB)?
Add your image, enter the dimensions you need, then type the limit under Keep file smaller than, or tap 20 KB, 50 KB, 100 KB or 200 KB, and press Resize. The tool keeps your dimensions and lowers the quality until the file fits under the limit.
Can I use the image resizer in MB?
Yes. Enter a number under Keep file smaller than and choose MB, or tap 1 MB or 2 MB. Large phone photos are often reduced to under 2 MB with only a small loss of quality.
What if my image can't get under the size limit?
The tool tells you and gives you the smallest result it can make at those dimensions. Use smaller dimensions, a larger limit, or the Image Compressor, which can reduce the pixel size as well to reach a small target.
How do I resize an image in cm?
Choose Centimetres in the Unit menu, enter the width or height, and pick the DPI. The tool converts the size to pixels using that DPI. Use 300 DPI for print and 72 or 96 DPI for screens.
Does the downloaded file remember its size in cm?
No. The file contains pixels. The size in centimetres only decides how many pixels are made at the DPI you choose. A print program or document decides how large that picture appears on paper.
Will resizing distort my image?
No, aspect ratio locking keeps your image from stretching unless you turn it off.
Are my images uploaded anywhere?
No. Images are resized locally in your browser and never leave your device.
Does resizing reduce file size too?
Usually yes, since fewer pixels means less data. To hit a particular size, use the Keep file smaller than box, or run the result through the Image Compressor.
Can I do a PDF resize here?
This tool is for images. To make a PDF smaller, use Compress PDF. To turn an image into a PDF, use JPG to PDF, which can also keep the PDF under a size such as 100KB or 200KB.
Can I resize to a larger size than the original?
Yes, but enlarging a photo beyond its original resolution will make it look softer or blurry, since the tool can't invent detail that wasn't there.
What's the difference between resizing and compressing?
Resizing changes the pixel dimensions (width × height). Compressing lowers the file size by re-encoding at a lower quality, without changing the dimensions. For the smallest file, resize first and then compress.