2.4 – Image Aspect Ratios Lesson

Lesson Overview

When generating images with ChatGPT, you may want them to fit into specific places—like headers, social posts, or phone wallpapers. At this time, ChatGPT does not let you pick exact pixel sizes. Instead, it keeps things simple with three basic options: wide, square, and tall. This lesson shows you how to guide the system toward the layout you need, using easy prompt wording.

If you leave size out of your prompt, ChatGPT will usually produce a square image—ideal for many cases, but not always the best fit. For banners or website headers, for instance, you’ll often want a wide image. If you’re making ads or social media profile frames, square is almost always preferred. Tall images work well for posters or vertical phone backgrounds.

The video demonstrates how to phrase prompts to get the best layout for your purpose and when you might need a separate tool to crop your image afterward. Understanding how to ask for wide, square, or tall images removes guesswork and saves you time, especially when preparing visuals for specific uses.

Who This Is For

If you create images for specific layouts and want more control with ChatGPT, this lesson is for you.

• Marketers preparing banners, ads, or social visuals
• Educators making teaching resources with specific image shapes
• Content creators posting to Instagram, Facebook, or similar
• Small business owners designing flyers or headers
• Anyone wanting consistent sizing for posters or phone wallpapers

Where This Fits in a Workflow

Using correct aspect ratios comes early in image creation—right at the prompt stage—so you can match your visual needs from the start. For example, when writing a prompt for an email campaign, you might specify a “wide” image to perfectly fit the email header. Or, when creating a picture for a product post, you would request a “square” image ready for social media without extra editing.

If your end use needs a size that ChatGPT does not directly support, you’ll first generate the image in the closest aspect ratio and then crop it to precise measurements using a tool such as Photoshop or Canva. This two-step process keeps the workflow practical and flexible.

Technical & Workflow Benefits

Previously, you’d have to manually crop or adjust every image after generation just to get the shape you need. Now, simply stating “wide,” “square,” or “tall” in your prompt gets you much closer to your required layout right away. This speeds up your workflow, lets you preview designs faster, and reduces repetitive editing. For example, marketers can quickly produce square image drafts for social campaigns, then refine only the best candidates, instead of resizing each option.

In real-world practice, this removes a common bottleneck—waiting until the end to see if an image actually “fits.” Now, you can work more flexibly and consistently, knowing the AI will follow your chosen layout as well as possible within its current limits.

Practice Exercise

Imagine you are preparing an image for three purposes: a website banner, an Instagram post, and a phone wallpaper.

1. Write three prompts to ChatGPT, each requesting the same subject (e.g., “a sunny forest”) but specifying “wide,” “square,” and “tall.”
2. Generate images using each prompt.
3. Look at the resulting images—how well do they match your intended use? Did specifying the aspect ratio in the prompt affect the outcome?

Reflect: Which layout matched your needs without needing to crop? Where might you still want to use an editing tool?

Course Context Recap

This lesson follows earlier discussions on prompt structure and continues helping you gain more creative control in ChatGPT’s image generation. Here, you learned about working with aspect ratios as one more way to tailor outputs to your needs. Up next, the course will introduce more ways to refine and adjust your images after they’re created. Keep exploring further lessons in the course to become more skilled at getting the right images for any project.