ConvertBox Logo
ConvertBox

Resize Image

Change image dimensions online. Resize JPG, PNG, WebP, and HEIC files by percentage, width, or height in your browser. Free, secure, and preserves aspect ratio.

📐

Select Image Files

You can resize multiple files at once

Max file size: 50MB • Multiple files allowed

or drag and drop · press Enter to browse

How to Use

  1. Upload the image you want to resize (JPG, PNG, WebP, or HEIC — up to 50MB per file).
  2. Enter your target width or height in pixels, or select a predefined scale percentage (e.g., 50%, 75%).
  3. Ensure the lock aspect ratio option is checked to prevent stretching or skewing of the original image.
  4. Click 'Resize Image' — resizing occurs entirely client-side using Canvas rendering.
  5. Save your resized image by downloading it as JPEG, PNG, or WebP.
  6. Your photos are secure as all dimension edits occur inside your browser sandbox.

All processing is done in your browser, and files are never sent to a server.

Frequently Asked Questions

Downscaling (making an image smaller) preserves details, but upscaling (making a small image much larger) will result in pixelation and softness as pixels are stretched. For best results, scale down or stay close to original dimensions.
Aspect ratio is the proportional relationship between width and height (e.g., 16:9). Locking it ensures that when you adjust width, height scales automatically to prevent stretching or squishing.
Yes. You can upload any supported image (like HEIC) and download the resized output in JPEG, PNG, or WebP format.
No. The entire resizing process is handled locally inside your browser sandbox using Canvas. Your images are never uploaded.
Our tool currently uses pixels (px) as the standard digital unit. To convert from inches/cm, calculate using your target PPI (pixels per inch, typically 72 for web, 300 for print).
Yes. Canvas rendering strips GPS, date, and camera EXIF details, which helps sanitize your images before uploading them to social media.
Images up to 50MB are supported. Processing speed depends on your local device CPU and RAM.
No. All operations are processed entirely inside your browser's local sandbox using client-side APIs (like WebAssembly, pdf-lib, or HTML5 Canvas). Your files and data never leave your device.
The tool is completely free with no usage limits. However, since processing occurs in your browser's memory, we recommend keeping file sizes under 50MB (especially for heavy files like PDFs or videos) to ensure stability.
No. All tools on ConvertBox are 100% free. We do not insert watermarks, limit features, or require any registration or payment.
Yes. Once the page and its local library dependencies are loaded in your browser, the conversion logic runs completely offline without needing an active internet connection.

Related tools

HEIC → JPG

Convert iPhone HEIC photos to JPG online. Batch up to 50MB per image, keep EXIF data optional, processed locally — no upload, no signup.

HEIC → JPG
Get Started

JPG → PNG

Convert JPG to PNG online — keep full transparency, batch up to 50MB per image, process locally in your browser. Free, no upload, no watermark.

JPG → PNG
Get Started

PNG → JPG

Convert PNG to JPG online — flatten transparency to white, choose 70–100% quality, batch up to 50MB per file. Free, browser-only, no signup.

PNG → JPG
Get Started

WebP → JPG

Convert WebP to JPG for universal compatibility. Choose 70–100% quality, batch up to 50MB per image, processed entirely in your browser.

WebP → JPG
Get Started

JPG → WebP

Convert JPG to WebP for smaller, faster-loading images — typically 25–35% smaller at equal quality. Batch up to 50MB per file, processed in your browser.

JPG → WebP
Get Started

Convert Image

Convert images between JPG, PNG, WebP and HEIC in your browser. Batch up to 50MB per file, lossless or quality-controlled output — no uploads, no signup.

JPGPNGWebPHEIC
Get Started