Resize Images Online Free - Image Resizer Tool

Resize images to any dimension for social media, websites, and more. Maintain aspect ratio, batch process, and preview results instantly in your browser.

Why Resize Images?

Image dimensions matter. Uploading a 4000×3000px photo to use as a 400×300px thumbnail wastes bandwidth, slows load times, and creates a poor user experience. Properly resized images load faster, look sharper, and consume less storage space.

Modern websites require images in multiple sizes for responsive design. A hero banner might need one size for desktop (1920×1080px) and another for mobile (750×1334px). Our resizer makes creating these variations effortless.

Popular Image Dimensions

Platform/Use Case	Dimensions	Aspect Ratio
Instagram Post (Square)	1080×1080px	1:1
Instagram Story	1080×1920px	9:16
Facebook Cover Photo	820×312px	~2.63:1
Twitter Header	1500×500px	3:1
LinkedIn Post	1200×627px	~1.91:1
Website Hero Banner	1920×1080px	16:9
Blog Featured Image	1200×630px	~1.91:1
Email Newsletter	600×400px	3:2

How to Resize Images in 3 Steps

Upload Your Images

Select one or multiple images to resize. Our tool supports all common formats including JPG, PNG, WebP, and more.

Choose Dimensions

Enter custom width/height, select from presets, or resize by percentage. Lock aspect ratio to prevent distortion.

Resize & Download

Preview results and download resized images instantly. Batch download all as a ZIP file for efficiency.

Start Resizing Images Free

Pro Tips for Resizing

Always downsize, not upsize: Shrinking images maintains quality; enlarging creates pixelation.
Maintain aspect ratio: Prevents stretched or squashed images that look unprofessional.
Compress after resizing: Combine resizing with compression for maximum file size reduction.
Use platform presets: Save time with one-click resizing for Instagram, Facebook, and other platforms.

Preset Sizes

Quick presets for social media, web, email, and common screen sizes. One-click resizing for popular platforms.

Mobile Optimized

Resize images specifically for mobile devices. Perfect for responsive web design and app development.

Aspect Ratio Lock

Maintain original proportions or specify custom ratios. Prevent distortion with intelligent cropping options.

Batch Resize

Process hundreds of images simultaneously. Apply the same dimensions to entire photo galleries with one click.

Related Tools

Compress Image

Convert Image

Social Media Optimizer

Frequently Asked Questions

How do I resize an image without losing quality?▼

Use bicubic or lanczos resampling algorithms (our tool uses the best method automatically). When downsizing, quality loss is minimal. When upsizing, some quality loss is inevitable, so it's best to start with high-resolution originals.

What's the difference between resize and scale?▼

Resizing changes the actual pixel dimensions (e.g., 2000×1500 to 1000×750). Scaling changes the file size without changing dimensions. Our resize tool adjusts pixel dimensions while maintaining aspect ratio.

Can I resize multiple images at once?▼

Yes! Our tool supports batch resizing. Upload multiple images and they'll all be resized to the same dimensions or percentage, maintaining consistent sizing across your entire image set.

What are the best dimensions for social media?▼

Instagram posts: 1080×1080px (square), 1080×1350px (portrait). Facebook: 1200×630px. Twitter: 1200×675px. LinkedIn: 1200×627px. Check our Social Media Image Optimizer guide for complete specifications.

Will resizing reduce my file size?▼

Yes, downsizing images (making them smaller) will reduce file size proportionally. A 50% dimension reduction typically results in 75% file size reduction. For maximum savings, use our Compress tool after resizing.

Can I maintain aspect ratio when resizing?▼

Absolutely! Our tool automatically maintains aspect ratio by default. You can also specify exact dimensions if you need a specific aspect ratio for your use case.

What if I need custom dimensions?▼

Simply enter your desired width and height. Our tool will resize your image to exact pixel dimensions. You can choose to maintain aspect ratio or stretch to fit specific dimensions.

Can I upscale images without quality loss?▼

Upscaling (making images larger) will reduce quality as pixels are interpolated. For best results, avoid upscaling more than 150% of original size. Always start with the highest resolution source available.

What formats support resizing?▼

All common image formats: JPG, PNG, WebP, AVIF, GIF, BMP, TIFF, and more. The output format remains the same as input, or you can convert during resize using our Convert tool.

Are my images uploaded anywhere?▼

No. All resizing happens in your browser using HTML5 Canvas APIs. Your images are processed locally and never uploaded to any server, ensuring complete privacy.

Ready to get started?

Process images in your browser. No upload, no signup, 100% free and private.

Browse All Tools