Resize Images Online
Resize your images to exact pixel dimensions with automatic aspect ratio preservation. Combine resizing with quality compression in a single step — upload a 4000×3000 photo, resize to 1200×900, and compress at 80% quality, all at once. Resizing before compressing is one of the most effective ways to reduce file size, since smaller dimensions mean dramatically fewer pixels to encode. Compresso handles everything in your browser with no server uploads.
Drop images here or click to upload
PNG, JPG, WebP, HEIC — up to 50MB each
Set exact width and height in pixels with precision
Automatic aspect ratio preservation prevents distortion
Resize and compress simultaneously in a single step
Supports PNG, JPG, WebP, and HEIC input formats
Batch resize multiple images to the same dimensions
Perfect for social media platform-specific dimensions
Convert formats while resizing (e.g., PNG to WebP)
100% private — images never leave your device
Why Resizing Matters
Resizing is often more impactful than quality compression alone. Reducing dimensions from 4000×3000 to 1200×900 removes 91% of the pixel data — before any quality compression even begins. This is why the most effective image optimization workflow is: resize first, then compress.
Recommended Dimensions by Platform
- Website hero images: 1200-1600px wide
- Blog/article images: 800-1000px wide
- E-commerce products: 1000-1200px wide
- Email images: 600-800px wide
- Instagram (square): 1080×1080
- Instagram (landscape): 1080×566
- Twitter/X: 1200×675
- Facebook: 1200×630
- LinkedIn: 1200×627
- Pinterest: 1000×1500
- YouTube thumbnail: 1280×720
Related Tools
- Compress for Web — web-optimized compression after resizing
- Bulk Compress — batch process with resize and compress
- Compress for Email — resize and compress for email
- Compress to Target Size — hit exact size limits
- Compress JPG — optimize resized photos
- Convert JPG to WebP — resize and convert in one step
Frequently Asked Questions
Does resizing reduce image quality?
Downscaling (making smaller) preserves quality very well — the resampling algorithm intelligently combines pixels. Upscaling (making larger) can introduce blurriness because the algorithm has to invent pixel data that doesn't exist. For best results, only resize images to smaller dimensions, or resize to match the display size you need.
Can I resize to specific social media dimensions?
Yes! Set the max width and height to your platform's recommended dimensions. Common sizes: Instagram square (1080×1080), Instagram landscape (1080×566), Twitter/X (1200×675), Facebook (1200×630), LinkedIn (1200×627), Pinterest (1000×1500), YouTube thumbnail (1280×720), TikTok (1080×1920).
Can I resize and compress at the same time?
Yes — this is one of Compresso's key features. Resize dimensions and adjust quality simultaneously, producing perfectly sized and optimized images in a single step. This is more efficient and produces better results than doing resize and compress in two separate tools.
Does Compresso maintain aspect ratio?
Yes, by default. When you set a max width or max height, the other dimension scales proportionally so the image doesn't get stretched or squished. This ensures your images always look natural. For exact dimensions (like 1080×1080 square), set both width and height.
What's the best image size for websites?
For full-width hero images: 1200-1600px wide. For content/blog images: 800-1000px wide. For thumbnails: 300-400px. For product photos: 1000-1200px wide. Serving images larger than their display size wastes bandwidth — a 4000px image displayed at 800px wastes 96% of its pixel data.
Can I batch resize multiple images?
Yes! Upload multiple images and resize them all to the same dimensions. This is useful for creating consistent image sets for a website, social media feed, or product catalog. All resized images can be downloaded as a ZIP.
Is resizing free?
Yes, completely free with no limits on file count, size, or daily usage. All processing happens in your browser — no account, no watermarks, no restrictions.
Why does resizing reduce file size so much?
File size is directly related to the number of pixels. A 4000×3000 image has 12 million pixels. Resizing to 1200×900 reduces that to 1.08 million pixels — 91% fewer pixels to encode. Combined with quality compression, you can easily achieve 95%+ file size reduction from the original.
Last updated: March 2026