Resize Images Online
Change image dimensions to exact pixel sizes. Lock aspect ratio or set custom dimensions.
Drag & drop images here
or click to browse
PNG, JPG, JPEG, WebP, AVIF, HEIC, BMP, GIF
Quality
Resize
Output Format
Before / After
How Image Resizing Works
Resizing changes how many pixels your image contains, which directly affects file size and visual sharpness. Downsizing a large photo before compressing it often saves far more space than quality adjustments alone — especially for websites, thumbnails, email attachments, and messaging apps.
Locking aspect ratio keeps width and height proportional so subjects are never stretched or distorted. Unlock it only when you need a fixed canvas, such as a banner with strict dimensions.
How to Resize Images Online
- Upload your image — drag and drop or click to browse. Supports PNG, JPG, WebP, HEIC, BMP, and GIF.
- Set dimensions — enter width, height, or both. Lock the aspect ratio to maintain proportions automatically.
- Choose output format — select JPG, PNG, or WebP. WebP delivers the smallest files for web use.
- Download — save individually or batch download as ZIP.
Common Image Sizes by Platform
- Instagram — Post: 1080×1080, Story: 1080×1920, Profile: 320×320
- Facebook — Cover: 820×312, Post: 1200×630, Profile: 170×170
- LinkedIn — Banner: 1584×396, Post: 1200×627
- YouTube — Thumbnail: 1280×720, Channel art: 2560×1440
- Twitter/X — Header: 1500×500, Post: 1600×900
Resize Tips for Better Results
- Downsize before compressing — a 4000px photo scaled to 1200px can drop from 5 MB to under 300 KB before you even touch the quality slider.
- Match your layout width — there is no point serving a 3000px hero image if your site’s content area is 1200px wide.
- Combine with compression — resize here, then compress the JPG or compress the PNG for maximum savings.
- Use preset sizes — for passport photos and social media, use our platform-specific resize tools with built-in presets.
Frequently Asked Questions
Can I resize while keeping the aspect ratio?
Yes! Lock the aspect ratio and set only width or height — the other dimension is calculated automatically to prevent distortion.
Does resizing reduce image quality?
Resizing down preserves quality. Resizing up can cause blurriness as pixels are interpolated. For best results, start with the largest version of your image.
What are the best sizes for social media?
Instagram post: 1080×1080. Facebook cover: 820×312. YouTube thumbnail: 1280×720. LinkedIn banner: 1584×396. Use our platform-specific tools for exact presets.
Can I resize multiple images at once?
Yes — upload multiple images, set dimensions, and click Compress All. Download everything as a ZIP.
Are my images uploaded to a server?
No. Everything runs in your browser using HTML5 Canvas. Your images never leave your device.
This tool works offline — install CompressEazy as an app on any device.