## What is an Aspect Ratio? An aspect ratio is the proportional relationship between an image's width and its height. It is written as two numbers separated by a colon (e.g., 16:9). The first number is the width, and the second is the height. Understanding aspect ratios is critical because every social media platform crops images differently. If you upload a 16:9 landscape photo to an Instagram portrait post, the sides will be brutally cropped off. ## The Social Media Cheat Sheet ### Instagram - **Square Posts:** 1:1 (1080 x 1080 px) - **Portrait Posts:** 4:5 (1080 x 1350 px) - *Highly recommended as it takes up the most screen real estate.* - **Stories & Reels:** 9:16 (1080 x 1920 px) ### X (Twitter) - **In-Stream Photos:** 16:9 (1200 x 675 px) - **Profile Header:** 3:1 (1500 x 500 px) ### TikTok - **Videos:** 9:16 (1080 x 1920 px) ### YouTube - **Thumbnails:** 16:9 (1280 x 720 px) - **Shorts:** 9:16 (1080 x 1920 px) ## How to Fix Your Images If you have an amazing photo that doesn't fit the required aspect ratio, you have two options: 1. **Crop It:** Use ToolFusion's [Image Cropper](/image/image-crop) to visually select the exact 4:5 or 1:1 square you need for Instagram. 2. **Resize It:** Use the [Image Resizer](/image/image-resize) to change the exact pixel dimensions. Be careful, though—changing the aspect ratio via resizing will stretch and distort your image. It's usually better to crop!