Resize Image Pixels Online (Free)

By Mukeem, who builds and maintains ToolBuny · Updated October 2026

To resize image pixels online, upload your JPG, JPEG or PNG, enter the new width and height in pixels, and click Resize Image. Switch on Maintain Aspect Ratio so nothing gets stretched, then download the result. You pay nothing, create no account, and your file is handled inside the browser tab.

A photo can be rejected for its dimensions even when its weight is fine. A profile slot may want 600 × 600, a link preview 1200 × 630, a banner a width of 800. This pixel resizer gets you to those numbers fast. If a KB cap applies too, the optional field below handles both jobs at once.

Pixels in one minute

Every digital picture is a mosaic. Each tiny tile holds one colour, and millions of tiles side by side form the photo you see. Width and height tell you how many tiles run across and how many run down.

More tiles give finer detail and a heavier file. Fewer tiles give a smaller, lighter picture. So image size in pixels describes the shape of the picture, while KB describes the weight of the file. They are linked, but they aren’t the same thing, and this page lets you set both.

How to change the pixel size of an image

Upload the image, enter the width and height in pixels, and click Resize Image.

1. Add your picture. If it’s the wrong one, press Change Images and choose again.
2. Fill in Width (PX) and Height (PX).
3. Tick Maintain Aspect Ratio to type one value and have the other calculated for you.
4. Use Compress Image To Specific Size (Optional) only when a KB cap also applies.
5. Pick JPG, JPEG or PNG as the output.
6. Press Resize Image, then Download.

My test: 1024 × 1536 px and 100 KB together

My starting file was a 2.48 MB portrait. I entered 1024 and 1536, wrote 100 in the KB box and chose JPG. The result card read 1024 × 1536 px with a file of 98.3 KB.

Doing the pixel change and the weight limit together is what makes this image resizer in pixels and KB handy: one press, and the picture came out at the shape I wanted and under the cap I set.

SHow Image

Sample photo used for testing.

Aspect ratio, without the maths headache

Divide the width by the height and you have the aspect ratio. A picture of 3000 × 2000 works out to 3:2.

Keep the lock on, type 900 as the width, and the height settles at 600. The shape stays true.

Switch the lock off and enter numbers that don’t follow the original shape, and the picture gets squashed or pulled wide. If a form insists on a fixed pixel height and width that don’t match your photo’s shape, trim the photo to that shape first, then resize.

Pixel size from centimetres and inches

Printers talk in inches and centimetres, screens talk in pixels, and DPI (dots per inch) connects the two. To convert, multiply inches by DPI. If you start from centimetres, divide by 2.54 to get inches first.

Here is a quick pixel converter chart at 300 DPI, the common print setting:

To find out the DPI stored in your file, use our Image DPI Checker.

Reduce pixel size or increase it?

Going smaller: enter lower numbers to reduce pixel size. The picture usually stays crisp, since you are throwing away surplus detail. It is also the fastest route to a lighter file, because fewer pixels carry fewer bytes. Think of it as a pixel reducer that needs no settings.

Going bigger: enter higher numbers to increase the pixel count of an image, but keep expectations realistic. The tool only stretches what the file already holds, so an enlarged small picture turns soft. Whenever you can, begin with the largest original you have.

Check your result before you upload

• Look at the file’s properties on your device to confirm the new width and height.
• Zoom in on faces and lettering. Rough edges mean the KB cap was too tight, so loosen it slightly.
• If the portal still refuses the file, reread its instructions and follow the exact figures it prints, not numbers from a forwarded message.
• Only the weight matters? Go to Reduce Image Size in KB. Need a heavier file? Try Increase Image Size in KB.
• Preparing an ID picture? Passport Size Photo is made for that.

Edit pixel size on phone or computer

On a phone, open the page in Chrome or Safari, pick a photo from the gallery, enter your numbers and save the output. On a laptop, drop the file onto the upload area. No app or software is needed on either.

Your pictures stay on your device

Resizing runs inside your browser, so your photo never travels to a server. You can verify it yourself: press F12, open the Network tab, resize a picture and watch the activity. Your image won’t appear as something being sent out.

Photo ke pixel kaise badlein

Pehle upload box se apni photo daalo. Galat photo aa gayi ho to “Change Images” se badal lo. Width aur Height ke dabbon mein jo pixel chahiye wo likho. Photo ki shape na bigde, isliye “Maintain Aspect Ratio” tick rakho. Form mein KB ki limit bhi hai to neeche wale optional dabbe mein number likho. Phir “Resize Image” dabao aur “Download” se photo le lo. Isme koi paisa ya account nahi lagta.