What is Image Resolution?

Image resolution measures pixel dimensions and file size. Width × height in pixels determines display size and quality. Megapixels (millions of pixels) is the marketing number. File size depends on resolution + compression + format. Aspect ratio determines shape (16:9 widescreen, 1:1 square, 4:3 classic).

Tips

• Web images: 72 DPI sufficient, smaller file
• Print: 300 DPI minimum for sharp output
• 16:9 standard for HD/4K video
• 1:1 (square) ideal for Instagram
• 9:16 vertical for phone displays, TikTok, Stories

FAQs

Reduce file size without losing quality?

Use modern formats (WebP, AVIF) — smaller than JPG. Or compress JPG with quality 80-90 — visually identical to 100%.

4K resolution?

3840 × 2160 pixels (8.3 megapixels). 4x more pixels than HD 1920×1080.

DPI matters?

For print: yes. For web: only pixel dimensions matter; DPI is just metadata not affecting display.