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Image Resizer

Resize any image to exact pixel dimensions or by percentage scale. Lock the aspect ratio to prevent distortion, or set custom width and height independently. Supports JPG, PNG, and WebP — all processing runs in your browser so your images are never uploaded to any server.

🔒 100% private — never uploaded⚡ Instant results🆓 Always free🚫 No signup required🖥️ Runs in your browser
📏
Drop image here or click to upload
JPG, PNG, WebP, GIF, BMP supported

How to Use Image Resizer

  1. 1

    Upload your image

    Click the upload area or drag and drop a JPG, PNG, or WebP image. The original dimensions are displayed immediately so you know your starting point.

  2. 2

    Choose resize mode

    Select "By Pixels" to enter exact dimensions, or "By Percentage" to scale proportionally (e.g. 50% halves the size, 200% doubles it).

  3. 3

    Enter dimensions

    Type the target width or height. With aspect ratio lock enabled, the other dimension adjusts automatically to maintain proportions and prevent stretching.

  4. 4

    Resize the image

    Click the Resize button. The browser redraws the image at the new dimensions using the Canvas API — no server required.

  5. 5

    Download

    Preview the resized image and download it as JPG, PNG, or WebP depending on your needs.

When to Use This Tool

Social media profile photos
Every platform has a required profile picture size. Resize to exactly 400×400 for Twitter, 180×180 for Facebook, or 110×110 for Instagram without distortion.
Email and web optimisation
Large images slow down emails and web pages. Resize to the exact display size before embedding to reduce load times and bandwidth.
E-commerce product photos
Online shops require consistent product image dimensions. Resize all product photos to a uniform size for a professional, polished storefront.
Printing and documents
Resize images to specific print dimensions before inserting into Word, PowerPoint, or PDF documents to control the exact output size.
App and web development
Frontend assets must match their CSS display dimensions exactly. Resize images to the rendered size to avoid unnecessary pixel data being downloaded.

Quick Reference

FeatureDetail
Supported formatsJPG, PNG, WebP
Resize modesBy pixels (width × height) or by percentage
Aspect ratio lockYes — auto-adjusts opposite dimension
Max file size20 MB per image
Output formatsJPG, PNG, WebP
Server uploadNever — 100% browser-based
WatermarkNone
CostFree, no account needed

About Image Resizer

The Image Resizer lets you change the dimensions of any image to exact pixel sizes, specific aspect ratios, or a percentage of the original size. Whether you need a specific size for a social media profile photo, a product listing, a banner, or a web page, the image resizer gives you pixel-perfect control with real-time preview and instant browser-based processing.

Image resizing is needed for:

  • Resizing profile photos to platform-specific requirements (400×400 for Twitter, 320×320 for Instagram)
  • Scaling down high-resolution DSLR photos for web upload without degrading quality visually
  • Resizing product images to consistent dimensions before e-commerce listing
  • Reducing image file size before emailing by scaling to smaller dimensions
  • Upscaling small images for presentations where a larger size is needed

Resizing is performed via the HTML5 Canvas API with optional high-quality interpolation. When downscaling, the tool uses a Lanczos resampling algorithm (via a WebAssembly implementation) for the sharpest possible results — Lanczos produces visibly sharper edges than the default browser bilinear interpolation, especially on images with text and fine detail. When upscaling, bilinear interpolation is used since true upscaling cannot recover detail that doesn't exist in the source. Aspect ratio locking is enforced mathematically to prevent any distortion.

Input formats: JPG, PNG, WebP, BMP, GIF. Resize modes: exact width×height, width only (auto height), height only (auto width), or percentage scale. Aspect ratio: locked by default, unlockable for stretch resizing. Output format: JPG or PNG. Max input: 20 MB. All processing is browser-based.

Resizing happens entirely in your browser — no file is uploaded to any server. The resized image is generated locally and downloaded directly to your device. For a batch of images all needing the same dimensions, use the Bulk Image Resizer. After resizing, compress the output with the Image Compressor to minimize file size further.

Pro Tips for Image Resizer

1

For retina/HiDPI displays, always resize images to 2× the display size — a 600px wide image needs to be 1200px to appear sharp on modern MacBooks and iPhones.

2

When resizing for specific social platforms, check the recommended sizes rather than the minimum — Instagram recommends 1080×1080 minimum for posts, not 600×600.

3

Downscaling a large photo to a smaller size is always better quality than upscaling a small photo — always start with the highest resolution source available.

4

PNG files with large dimensions but simple content (logos, icons) often compress dramatically on resize — a 500×500 PNG logo may be 5× smaller than a 2000×2000 version.

Frequently Asked Questions

What is the difference between resizing by pixels and by percentage?+
Resizing by pixels lets you set an exact target dimension (e.g. 800px wide), which is useful when a platform requires specific sizes. Resizing by percentage scales the image relative to its current size — 50% makes it half as large, 200% doubles it. Percentage mode is convenient when you just want to make an image generally smaller or larger without worrying about exact numbers.
Will resizing reduce image quality?+
Scaling down (making an image smaller) generally preserves quality very well. Scaling up (enlarging) can introduce blurring or pixelation because the browser must invent new pixel data that was not in the original. For best results, avoid enlarging an image by more than 120–150% of its original size.
What is aspect ratio lock and when should I use it?+
Aspect ratio lock keeps the width-to-height ratio constant. When you change one dimension, the other adjusts automatically. Use it whenever you want to make an image smaller or larger without distorting it. Turn it off only when you intentionally want to stretch or squish an image to different proportions.
Can I resize multiple images at once?+
The standard resizer handles one image at a time. For bulk resizing, use the Bulk Image Resizer tool, which lets you apply the same dimensions to many images simultaneously and download them all at once.
What output format should I choose?+
Use JPG for photographs and images without transparency — it produces the smallest file sizes. Use PNG when you need transparency or a lossless result. Use WebP for web assets when browser compatibility allows — it offers the best balance of quality and compression.
Is there a minimum or maximum size I can resize to?+
The tool can resize down to 1×1 pixels and up to very large dimensions, limited only by your browser memory. For very large outputs (e.g. 10,000×10,000 pixels), the browser may slow down or run out of memory. Practically, keep output dimensions under 8,000px on either side for reliable performance.

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Your input is processed locally in your browser and is never stored, transmitted, or shared with any server. See our Privacy Policy.

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