Image Resizer

How This Resizer Works

When you pick a file, your browser reads it into memory and decodes it as a picture. The tool then draws that picture onto an invisible canvas at the new width and height, and asks the browser to encode the canvas as a fresh PNG, JPEG or WebP file. The File Size line is the size of that fresh file, recalculated every time you move a slider, so what you see is exactly what the Download button saves. No part of this leaves your computer, which is why the tool keeps working if you switch the internet off after the page has loaded.

• Percentage scales both sides by the same factor, from 10 to 200 percent.
• Custom Dimensions sets exact pixel values; with Maintain aspect ratio ticked, typing one side fills in the other.
• Preset Sizes jumps to common screen sizes such as 1920 by 1080 or 512 by 512.
• Output Format chooses the encoder. The quality slider applies to JPEG and WebP and is hidden for PNG, which is always lossless.

Two side effects of re-encoding are worth knowing. The new file carries none of the original's metadata, so GPS coordinates and camera details from a phone photo are gone. And an animated GIF loses its animation, because only the first frame is drawn.

Resizing Dimensions vs Compressing Quality

Two different things shrink an image file. Resizing reduces the number of pixels: halving the width and the height leaves a quarter of the pixels, and the file size falls by roughly the same proportion. Compressing keeps every pixel but stores the colours less precisely, which is what the quality slider controls for JPEG and WebP. At 90 percent the loss is invisible; at 70 to 80 percent the file is far smaller and the photo still looks fine on a screen; below 50 percent blocky patches appear around edges and in smooth areas such as skin and sky.

Dimensions matter more than quality. A 12-megapixel phone photo is around 4000 by 3000 pixels, and no quality setting will bring it near 50 KB. Once the same photo is 413 by 531 pixels, it lands under 50 KB at a quality most people cannot tell from the original. Resize first, then compress.

JPEG, PNG or WebP?

One trap when converting: JPEG has no transparency, so a PNG logo or signature with a transparent background comes out with a black background after conversion. Keep PNG for those, or flatten the image onto white first.

Hitting a Target Size for Application Forms

Exam portals, job applications and university admissions reject uploads that miss their photo and signature rules, and every portal publishes its own figures in the notification or the upload page. Most ask for a photograph of a few tens of kilobytes at a size close to a printed passport photo, a signature of around 10 to 30 KB in a wide, short frame, and scanned documents in the range of 100 KB to 1 MB. The numbers differ between portals and change between years, so copy them from the page you are uploading to, and then:

1. Choose Custom Dimensions, untick Maintain aspect ratio if the portal gives both a width and a height, and type the pixel values it asks for. If it gives centimetres, use the DPI table below.
2. Pick the format the portal accepts. JPEG is the safe choice for photographs; use PNG only if the form asks for it.
3. Lower the quality slider until the File Size line is inside the allowed range. Stay above the minimum too: some portals reject files that are too small.
4. Download, then open the file once to confirm it is not blurred and that the face or signature fills the frame.

Signatures are easiest scanned or photographed on plain white paper in black ink, cropped tight to the ink before resizing. The article on image dimensions for Indian job applications walks through the photo and signature process step by step, and how to compress and resize images without losing quality covers the trade-offs in more depth.

Pixels, Centimetres and DPI

A digital image has no physical size, only a number of pixels. DPI (dots per inch) is a print setting that says how densely those pixels should be laid on paper, so a 3.5 by 4.5 cm photo printed at 300 DPI needs 413 by 531 pixels (divide the centimetres by 2.54 and multiply by 300). Portals that quote a size in centimetres or a DPI value are really asking for a pixel count, and this tool does not write a DPI value into the file at all.

Metadata and Privacy

Photos from a phone carry EXIF metadata: the exact time, the camera model, the settings, and often the GPS coordinates of where the picture was taken. Uploading such a file to a form or a marketplace listing hands all of that over. Because this tool builds a new file from the pixels alone, the download contains none of the original metadata. Resizing a photo here before sharing it is therefore also a quick way to strip location data. The one thing to check is orientation: browsers apply the phone's rotation tag while decoding, so a portrait photo stays upright, but if a very old file appears sideways, rotate it in your gallery app before uploading.

Frequently Asked Questions