Image Resizer — Resize Images Online, Free and Private
Our free online image resizer lets you resize JPG, PNG, WebP, GIF, and other image formats instantly in your browser. No images are uploaded to any server — all processing happens locally on your device using the HTML Canvas API. Resize to exact dimensions, scale by percentage, fit within a bounding box, or fill and crop. Convert between formats and adjust JPEG quality. Download instantly.
How to Resize an Image
Step 1 — Upload Your Image
Drag and drop your image onto the upload area or click to browse your files. The tool accepts JPG, PNG, WebP, GIF, BMP, and SVG files. Your image is loaded directly into your browser — nothing is sent to a server.
Step 2 — Set Your Dimensions
Enter the new width or height in pixels. With the aspect ratio lock enabled (the default), the other dimension updates automatically to preserve the original proportions. Alternatively, use percentage scaling or choose fit within / fill and crop modes.
Step 3 — Choose Format and Quality
Select your output format — JPEG, PNG, or WebP. For JPEG and WebP, adjust the quality slider. A quality of 80–90% provides excellent visual quality with a significant file size reduction compared to 100%.
Step 4 — Download
Click Download to save the resized image. The filename automatically includes the new dimensions for easy reference.
Image Format Guide — JPEG vs PNG vs WebP
| Format | Best For | Transparency | Compression | Browser Support |
|---|---|---|---|---|
| JPEG / JPG | Photos, complex images with many colors | No | Lossy — good compression at quality 80–90% | Universal |
| PNG | Graphics, screenshots, images needing transparent background | Yes (alpha channel) | Lossless — larger files | Universal |
| WebP | All web images — photos and graphics | Yes (alpha channel) | Lossy and lossless — 25–35% smaller than JPEG | All modern browsers (Chrome, Firefox, Safari 14+, Edge) |
| GIF | Simple animations, icons | Yes (1-bit — not smooth) | Lossless — limited to 256 colors | Universal |
| SVG | Logos, icons, illustrations | Yes | Vector — scales without quality loss | Universal |
| BMP | Legacy Windows graphics | Sometimes | No compression — very large files | Universal (avoid for web) |
| AVIF | Next-gen web images | Yes | Best compression — 50% smaller than JPEG | Growing (Chrome, Firefox, limited Safari) |
JPEG Quality Settings — What to Use
JPEG quality is a trade-off between file size and visual quality. Higher quality means larger files. Here is a guide to choosing the right quality level:
| Quality | File Size | Visual Quality | Best For |
|---|---|---|---|
| 100% | Very large (no compression) | Perfect | Source files, archiving |
| 90–95% | Large | Excellent, barely distinguishable from 100% | Print-quality output |
| 80–90% | Medium | Very good, imperceptible loss to most people | Web images, social media (recommended) |
| 70–80% | Small | Good, minor artifacts visible on close inspection | Thumbnails, previews |
| 50–70% | Very small | Moderate, compression artifacts visible | Low-bandwidth delivery |
| Below 50% | Tiny | Poor — obvious blocking artifacts | Avoid unless file size is critical |
Common Image Sizes for Web and Social Media
| Platform / Use | Width | Height | Format | Notes |
|---|---|---|---|---|
| Website hero image | 1920 | 1080 | WebP/JPG | 16:9 landscape |
| Website thumbnail | 600 | 400 | WebP/JPG | 3:2 ratio common |
| Website favicon | 32 | 32 | PNG/ICO | Square, small |
| Instagram Post | 1080 | 1080 | JPG | Square 1:1 |
| Instagram Portrait | 1080 | 1350 | JPG | 4:5 portrait |
| Instagram Story | 1080 | 1920 | JPG | 9:16 vertical |
| Facebook Post | 1200 | 630 | JPG | 1.91:1 landscape |
| Twitter/X Post | 1200 | 675 | JPG | 16:9 |
| YouTube Thumbnail | 1280 | 720 | JPG | 16:9, under 2MB |
| LinkedIn Post | 1200 | 627 | JPG | 1.91:1 |
| Email header | 600 | 200 | JPG/PNG | 3:1 landscape |
| Open Graph image | 1200 | 630 | JPG | Social preview cards |
How to Reduce Image File Size
Reducing image file size improves website loading speed, reduces bandwidth usage, and improves Core Web Vitals scores. Here are the most effective techniques:
- Resize to display dimensions — Never use a 4000px wide image if it will display at 800px. Resize to the actual display size before uploading. A 4000×3000 image resized to 800×600 is typically 90% smaller.
- Convert to WebP — WebP produces files 25–35% smaller than JPEG at equivalent visual quality. Use this tool to convert JPEG and PNG images to WebP.
- Reduce JPEG quality — A quality of 80–85% is virtually indistinguishable from 100% to the human eye but can be 60–70% smaller. Use the quality slider to find the right balance.
- Use PNG only when needed — If your image does not require transparency, use JPEG or WebP instead of PNG. PNG files are lossless and significantly larger than equivalent JPEG files for photographs.
- Remove metadata — JPEG files often contain EXIF metadata (camera settings, GPS location, thumbnails) that adds file size. The canvas-based resize in this tool strips EXIF data automatically.