Everything you need to know about resizing images — for web, social media, email, and print. Pick your use case below or start with the tool.
Supported formats: JPG, PNG, GIF, WebP
Use case guides
Every platform has different requirements. These guides cover the most common scenarios with concrete dimensions, format recommendations, and step-by-step instructions.
Resize images for email
Avoid attachment size limits in Gmail and Outlook. Recommended: 1200 px wide, JPG 80%.
Resize images for WordPress
Improve Core Web Vitals and page speed. Featured images at 1200×628 px, products at 800×800 px.
Resize images for Instagram
Feed, Stories, Reels, and profile pictures — exact dimensions to prevent compression artifacts.
Reduce image size under 100 KB
For online forms, job applications, and government portals with strict file size limits.
Resize images without losing quality
What actually causes quality loss — and how to avoid it. Best format and quality settings.
Quick reference: image sizes by platform
| Use case | Size (px) | Format | Target size |
|---|---|---|---|
| Email attachment | 1200 × auto | JPG 80% | < 500 KB |
| WordPress featured image | 1200 × 628 | JPG 82% | < 150 KB |
| WooCommerce product | 800 × 800 | JPG 85% | < 100 KB |
| Instagram feed (portrait) | 1080 × 1350 | JPG 90% | < 3 MB |
| Instagram Stories / Reels | 1080 × 1920 | JPG 90% | < 3 MB |
| Online form / ID upload | 600 × 600 | JPG 80% | < 100 KB |
| YouTube thumbnail | 1280 × 720 | JPG 85% | < 2 MB |
JPG, PNG, or WebP — which format should you use?
- JPG — best for photos. Lossy compression, small files. Quality setting 75–85% is the sweet spot.
- PNG — best for logos, icons, screenshots, and anything with transparency. Lossless but larger files.
- WebP — best of both: 25–35% smaller than JPG at the same quality. Supported by all modern browsers. Use it if your platform accepts it.
The one rule that prevents most quality problems
Never enlarge an image. Always resize to equal or smaller dimensions than your original. Downscaling combines real pixel data and preserves quality. Upscaling invents data that doesn't exist and produces blurry results.
Keep one high-resolution master file (your original photo or PNG) and export resized JPGs from it as needed. Never re-save a JPEG from another JPEG multiple times.
FAQ: Image resizing basics
What is the best free tool to resize images online?
ResizeConvert.com — this tool. No registration, no watermarks on the free plan, processes images in seconds, supports JPG, PNG, WebP, and GIF. The resize, compress, crop, and convert tools are all available in one place.
Does resizing an image reduce its quality?
Downscaling (making smaller) with proper resampling does not cause visible quality loss. Upscaling (making larger) does. JPEG quality settings below 70% also cause visible artifacts. Keep quality at 75–85% and only resize downward for best results.
What is DPI and does it matter for web images?
DPI (dots per inch) is only relevant for print. For screens, only pixel dimensions matter. A 1200 × 628 px image at 72 DPI and the same image at 300 DPI display identically on a monitor — the DPI value is ignored by browsers. Set DPI only when preparing files for print.
How do I resize images in bulk?
The free version handles one image at a time. The Pro plan supports batch processing for multiple images in a single session — useful for product photos, event galleries, or blog image batches.