Image Resizer
Drop or choose a PNG, JPG, or WebP and resize it to an exact width and height, or scale it by percentage, with an aspect ratio lock that keeps your picture from stretching. The image is redrawn on a canvas inside your browser and saved straight to your device.
Your image never leaves your browser and is never uploaded to any server.
Drop an image here
or choose a file · or paste with Ctrl+V (Cmd+V)
🔒 Resized in your browser with a canvas. Never uploaded.
What is the Image Resizer?
This is a free, browser-based image resizer. Drop in or choose a PNG, JPG, or WebP and set a new
width and height in pixels, or scale the whole picture by a percentage. An aspect ratio lock
keeps the proportions correct so the result never looks squashed or stretched. When you are
happy with the numbers, the tool redraws the picture at the chosen size on a hidden
<canvas> and hands you a downloadable file. Everything runs on your device:
the image is decoded, resampled, and exported locally and is never uploaded, stored, or logged.
How to use it
- Add your image — click to choose a file, drag and drop it onto the drop zone, or paste with Ctrl+V (Cmd+V on Mac).
- Read the original dimensions and aspect ratio shown next to the preview.
- Pick a mode: type an exact width and height in pixels, or switch to percent and enter a scale such as 50.
- Keep the aspect ratio lock on to resize without distortion, or turn it off for a precise non-proportional size.
- Choose the output format (PNG, JPEG, or WebP) and, for the lossy formats, a quality level.
- Click Resize & download. The file saves to your device. Answer in, answer out, done.
The method behind it
Resizing on a canvas is straightforward but exact. The image is loaded into an off-screen
Image object so the browser knows its true pixel dimensions. A
<canvas> is then sized to your target width and height, and a single
drawImage call paints the source image into that smaller or larger rectangle. The
browser's built-in bilinear-style resampling smooths the pixels for you. With the aspect ratio
lock on, the missing dimension is computed from the original ratio — type a width and the height
follows from height = width × (originalHeight / originalWidth), and vice versa, with
both values rounded to whole pixels. Percent mode simply multiplies both dimensions by your
scale. Finally canvas.toBlob encodes the result in the format you picked and the
browser saves it locally.
Examples
- Fit a 4000×3000 photo to 1200px wide: with the lock on, type 1200 in the width field and the height auto-fills to 900, holding the 4:3 ratio. Export as JPEG to keep the file small.
- Halve a screenshot: switch to percent mode and enter 50. A 1920×1080 capture becomes 960×540, perfect for a blog post or a Slack message.
- Force an exact 512×512 icon: turn the lock off and set both fields to 512. The image fills the square exactly, even if the source was not already square.
Common use cases
- Shrinking phone photos before emailing or posting them so they upload faster.
- Hitting a forum, marketplace, or job-board upload limit that caps maximum width or height.
- Making square avatars, thumbnails, and social profile pictures at a fixed size.
- Scaling screenshots down to a tidy width for documentation, tickets, and blog posts.
- Preparing icons and assets at exact pixel sizes for an app, slide deck, or website.
Why use this one
Many online resizers send your file to a server, queue it, and email or watermark the result. This one does none of that. The picture is read and redrawn entirely in your browser, so it never leaves your device — which makes it safe for private screenshots, ID photos, internal logos, and client mockups. There is no sign-up, no watermark, no upload wait, and no limit on how many images you resize. Because the work happens locally, the resize is instant and the result is yours alone.
It is part of a small image toolkit. To make a file lighter without changing its dimensions, use the Image Compressor; to keep only part of a picture, try the Image Cropper; to change formats, reach for PNG to JPG; and to inline an image into code, use Image to Base64.
Frequently asked questions
Is my image uploaded to a server when I resize it?
No. The image is read and redrawn entirely inside your browser on a hidden canvas, then saved straight to your device. Nothing is sent over the network, stored, or logged, so private screenshots, ID photos, and client mockups stay on your machine. Close the tab and nothing remains.
How do I resize an image without stretching it?
Keep the aspect ratio lock on. When the lock is enabled, typing a new width recalculates the matching height automatically, and vice versa, so the picture keeps its original proportions and never looks squashed. Turn the lock off only when you deliberately want to distort to an exact width and height.
Can I resize by percentage instead of exact pixels?
Yes. Switch to the percent mode and enter a value such as 50 to make the image half its original size, or 200 to double it. The tool computes the resulting width and height for you and rounds to whole pixels, which is handy when you only care about the relative scale.
Which image formats can I resize and download?
You can load PNG, JPG, WebP, GIF, BMP, and most other formats your browser can render. For the download you can keep the source format or convert to PNG, JPEG, or WebP. Anything the browser cannot re-encode losslessly is saved as PNG so the download always works.
Does resizing reduce the file size?
Making an image smaller in pixels usually makes the file lighter, because there is less pixel data to store. Saving as JPEG or WebP shrinks it further with an adjustable quality slider. The tool shows the new file size after resizing so you can judge the result before you download.