Image Resizer
Resize any image to exact pixel dimensions or a percentage of the original — all inside your browser, with no file uploads. Choose a custom width and height or lock the aspect ratio so your image scales proportionally. Download the result as a PNG in one click.
How It Works
When you drop or select an image file, this tool reads it locally using the browser's File API and draws it onto an HTML5 Canvas element — your file never leaves your device.
You can resize by entering a target width or height in pixels. When "Keep aspect ratio" is enabled (the default), changing one dimension automatically updates the other to preserve the original proportions. This prevents stretching or squishing your image.
Alternatively, switch to percentage mode and enter a scale factor. 50% halves both dimensions; 200% doubles them. The tool calculates the new pixel dimensions and shows a live preview before you download.
Worked example: You have a 4000 × 3000 px photo from your camera. You need a 1200 × 900 px version for a web page. Enter 1200 in the width field with aspect ratio locked. The height field auto-fills to 900 (because 3000 × (1200/4000) = 900). Click Download and you get a 1200 × 900 PNG instantly.
For percentage mode: that same 4000 × 3000 image at 25% becomes 1000 × 750 px. Useful for batch-preview logic where you want a consistent scale factor regardless of the source size.
The downloaded file is always PNG, which is lossless. If you need JPEG or WebP output with compression, use the Image Compressor or Image Converter tools linked below.
Canvas-based resizing uses the browser's built-in bilinear/bicubic interpolation (controlled by the imageSmoothingQuality setting). The tool sets this to "high" for the best downscaling quality, reducing aliasing artifacts when shrinking large photos.
Frequently Asked Questions
Is my image uploaded to a server?
No. Everything happens inside your browser using the Canvas API. Your image is never sent over the network. You can even use this tool with your internet connection turned off.
What image formats can I resize?
Any format your browser supports: JPEG, PNG, WebP, GIF, AVIF, BMP, and SVG. The output is always PNG. Use the Image Converter tool if you need a different output format.
Why is the output always PNG?
PNG is lossless, so the resized image has no additional compression artifacts. If you need a smaller JPEG or WebP file, run the downloaded PNG through the Image Compressor tool.
Does resizing degrade image quality?
Enlarging (upscaling) beyond 100% will always look softer or pixelated because no new detail can be invented. Downscaling generally looks sharp. This tool uses high-quality smoothing to minimise artefacts.
What is the maximum file size I can resize?
The tool accepts images up to 20 MB. Very large images (above 8000 × 8000 px) may cause the browser to use significant memory; keep tabs on your device RAM when working with extremely large files.