Image Resize Tool - High Quality Scaling

How It Works

Our resize tool uses Lanczos interpolation, one of the highest quality resampling algorithms available. Unlike simple bilinear scaling that can produce blurry results, Lanczos preserves sharp edges and fine details when enlarging or reducing images.

The tool runs entirely in your browser using the HTML5 Canvas API with optimized JavaScript. Your images stay on your device—nothing is uploaded to any server.

Why Lanczos? Lanczos interpolation uses a windowed sinc function to resample images. It produces sharper results than bilinear or bicubic methods, especially when upscaling. It's the same algorithm used by professional tools like Photoshop and GIMP.

Key Features

📐 Flexible Sizing

Resize by percentage, exact dimensions, or scale factor. Lock aspect ratio or resize freely.

🔍 Sharp Results

Lanczos interpolation preserves edges and details better than standard browser scaling.

⚡ Instant Preview

See results immediately as you adjust settings. No waiting for processing.

🔒 Private

All processing happens locally. Your images never leave your browser.

Resize Options

Option	Description
Scale Factor	Multiply dimensions by 2x, 3x, 4x, or custom value
Percentage	Scale to 25%, 50%, 75%, 150%, 200%, etc.
Exact Dimensions	Enter specific width and height in pixels
Lock Aspect Ratio	Maintain original proportions when resizing

Option

Description

Scale Factor

Multiply dimensions by 2x, 3x, 4x, or custom value

Percentage

Scale to 25%, 50%, 75%, 150%, 200%, etc.

Exact Dimensions

Enter specific width and height in pixels

Lock Aspect Ratio

Maintain original proportions when resizing

Best Use Cases

Web Optimization: Reduce image dimensions for faster page loading

Print Preparation: Upscale images for higher resolution printing

Social Media: Resize photos to fit platform requirements

Thumbnails: Create consistent sized thumbnails from various source images

Email Attachments: Reduce file size by scaling down large photos

Tips for Best Results

Upscaling limits: While Lanczos produces excellent results, no algorithm can add detail that isn't there. For extreme upscaling (4x+), consider the AI Resize tool.

Start with quality: Begin with the highest resolution source image available for best results.

Downscaling: When reducing size, Lanczos prevents the moiré patterns and aliasing that simpler methods can produce.

Aspect ratio: Lock the aspect ratio to prevent distortion unless you intentionally want to stretch the image.

Resize vs AI Resize

Not sure which tool to use? Here's a quick comparison:

Standard Resize	AI Resize
Best for moderate scaling (up to 2-3x)	Better for extreme upscaling (4x)
Instant processing	Requires AI model download
Preserves exact pixel data	Adds AI-generated detail
Works on any device	Works best on modern devices

Standard Resize

AI Resize

Best for moderate scaling (up to 2-3x)

Better for extreme upscaling (4x)

Instant processing

Requires AI model download

Preserves exact pixel data

Adds AI-generated detail

Works on any device

Works best on modern devices

Try Resize Tool →

Image Resize