🖼️ Image Resizer

Resize JPG, PNG, WebP images to any size. Set pixels or percentage, lock aspect ratio, preview instantly, download immediately.

📁 Upload Image
📂

Click to choose or drag & drop an image here

Supports JPG, PNG, WebP, BMP, GIF

What is the Image Resizer?

The Image Resizer is a free, browser-based tool that lets you change the dimensions of any image — JPG, PNG, WebP, BMP, or GIF — without installing software or uploading files to a server. Everything is processed entirely in your browser using the HTML5 Canvas API, which means your images stay completely private. The tool supports both exact pixel dimensions and percentage-based scaling, includes an aspect ratio lock to prevent distortion, and lets you choose the output format and quality.

Resizing images is a common need for web developers, designers, social media managers, and photographers. Whether you're optimising images for page speed, fitting a photo to specific platform dimensions, or reducing file size for email attachments, this tool gives you full control with instant visual feedback.

How to Use — Step-by-Step

  1. Click the upload area or drag and drop your image file (JPG, PNG, WebP, BMP, or GIF).
  2. The original dimensions and file size are displayed immediately after the image loads.
  3. Choose By Pixels to set exact width and height in pixels, or By Percentage to scale relative to the original size.
  4. Enable Lock aspect ratio to automatically adjust height when you change width (and vice versa), preventing stretching or squashing.
  5. Optionally choose an output format (JPEG, PNG, WebP) and adjust quality for JPEG/WebP outputs.
  6. Click Resize & Preview to see the result side by side, then click Download to save the resized image.

Key Features

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Pixel & Percentage

Set exact pixel dimensions or scale by percentage from 10% to 200% with a live preview of the resulting dimensions.

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Aspect Ratio Lock

Keep your image proportions intact automatically. Changing width adjusts height and vice versa when the lock is enabled.

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Format & Quality

Output as JPEG, PNG, or WebP. Adjust JPEG/WebP quality from 60–100% to balance file size and visual quality.

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Side-by-side Preview

See the original and resized images next to each other before downloading, with estimated file size shown.

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Quick Presets

One-click presets for common resolutions: 1920×1080, 1280×720, 800×600, 640×480, 400×400, and 200×200.

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100% Private

Your images are never uploaded to any server. All resizing happens locally in your browser using the Canvas API.

Frequently Asked Questions

❓ Will resizing an image reduce its quality?
Reducing image dimensions always results in some data loss because you're discarding pixels. However, this tool uses imageSmoothingQuality: 'high' on the Canvas API which applies bilinear interpolation for better results. For lossless output, choose PNG format. For JPEG or WebP, use a quality setting of 85–95% to get small file sizes with minimal visible quality loss.
❓ What image formats can I upload?
This tool accepts JPG/JPEG, PNG, WebP, BMP, and GIF images. Note that for animated GIFs, only the first frame will be used. The browser's native image decoding handles all supported formats.
❓ Is there a maximum file size limit?
Since processing happens entirely in your browser, the limit depends on your device's available memory. In practice, images up to 20–30 MB work fine on modern devices. Very large images (50+ MP) may be slow or cause browser warnings on lower-end hardware.
❓ Can I make an image larger (upscale)?
Yes. You can set any target dimensions, including larger than the original. However, upscaling a raster image will reduce its sharpness because the browser must interpolate new pixels from existing ones. For best upscaling results, start with the highest resolution original you have.
❓ Why is the PNG output larger than the JPEG output?
PNG is a lossless format that preserves every pixel exactly, which results in larger file sizes. JPEG and WebP use lossy compression that discards some image data to achieve much smaller files. For photos and complex images, JPEG or WebP at 85–90% quality gives an excellent balance. For screenshots, logos, or images with sharp edges and text, PNG is usually better.