Image Resizing Guide: Dimensions, Compression, and Best Practices
5 min read · Updated June 2026
Resizing an image isn't just about changing pixel dimensions — it's about matching the right size, quality, and format to the destination. A photo that looks great on a 4K monitor can be a 10MB burden on a mobile webpage.
Common Image Sizes
| Use Case | Recommended Size | Format |
|---|---|---|
| Website hero | 1200-1920px wide | WebP or JPEG |
| Blog post | 800-1200px wide | WebP or JPEG |
| Instagram post | 1080 × 1080px | JPEG |
| Facebook share | 1200 × 630px | JPEG |
| Print (300 DPI) | Varies by print size | PNG or TIFF |
| 600px wide max | JPEG, quality 60-70% |
Resolution vs DPI
- Resolution — Total pixels (e.g., 4000 × 3000 = 12 megapixels)
- DPI (Dots Per Inch) — Only matters for print. 72 DPI for web, 300 DPI for print.
- A 4×6 inch print at 300 DPI needs 1200 × 1800 pixels. The same image at 72 DPI is still 1200 × 1800 pixels on screen — DPI doesn't affect web display.
Compression Quality Guide
- 90-100% — Minimal compression, large files. For archival or print.
- 70-85% — Good balance. Recommended for most web images.
- 50-65% — Aggressive compression, visible artifacts. Only for thumbnails.
⛶ Resize your images
Use our Image Resize & Convert tool to resize, compress, and convert images — 100% in your browser with quality control.
The Bottom Line
- Match image dimensions to the destination — don't load a 4000px image for a 800px display
- Use 70-85% quality for web — the difference from 100% is barely visible
- DPI only matters for print, not web display
- Convert to WebP for 25-35% smaller files at the same quality
Disclaimer: This guide is for informational purposes only.