Midjourney Aspect Ratio: How to Change it and Shape the Images Perfectly

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As an avid Midjourney user and image creation geek, aspect ratio is one of my favorite features. Getting it right can totally transform your AI art. After extensive experimentation, I‘m excited to share everything I‘ve learned about properly shaping images with aspect ratios in Midjourney.

Let‘s dive in!

What is Aspect Ratio and Why It Matters

Simply put, aspect ratio refers to the width-to-height ratio of an image or video. It is expressed as two numbers separated by a colon, like 16:9.

This ratio defines the orientation and proportions of the rectangular frame. For example, 16:9 is a landscape widescreen aspect ratio. 9:16 is a vertical portrait orientation.

But aspect ratio isn‘t just a technical specification. It profoundly impacts the aesthetic experience and emotional appeal of visual media.

Consider cinema. Movies shot in widescreen 16:9 or 2.39:1 feel expansive, cinematic, and sweeping. The same films viewed in old-school 4:3 look boxy, cramped, and less impactful.

The same dramatic principles apply to other visual domains like social media marketing.

For example, vertical 2:3 Instagram Stories ads tend to perform better than awkwardly letterboxed 16:9 ads on mobile. The shape just fits the content medium better.

That‘s why aspect ratio choices carry such artistic and practical importance. And with AI image generation, we have an opportunity to fully harness their power.

Midjourney Changes the Aspect Ratio Game

Traditionally, aspect ratio is something decided in post-production after capturing images or footage. You crop and edit to the desired frame size.

But Midjourney flips this workflow on its head in a fascinating way. Since it‘s creating images directly from text prompts, there is no "original" image to crop.

The aspect ratio must be defined upfront as part of the prompt itself.

This unlocks creative possibilities that were never before possible! By carefully formatting the --ar parameter, we can define any custom aspect ratio we want before generation.

It‘s like directing an AI illustration or filming a AI-generated movie scene.

But get the aspect ratio wrong, and your images won‘t align with their intended use. Just imagine creating a perfect YouTube thumbnail at 1:1 square orientation – it would get awkwardly stretched and distorted by YouTube‘s 16:9 player.

That‘s why properly controlling aspect ratio is so crucial for prompt engineering. Let‘s dig into how it works.

Specifying Aspect Ratio in Prompts

Midjourney provides two main parameters for defining a custom aspect ratio:


The --ar parameter is the easiest option. Simply add it to your prompt followed by the desired ratio:

An astronaut floating in space --ar 16:9

This will render the astronaut scene at a widescreen 16:9 aspect ratio.


The --aspect parameter works the same way:

A cute puppy portrait --aspect 9:16 

Now we‘ve generated a nice vertical portrait of the pup at 9:16 aspect ratio – perfect for Instagram!

Both parameters work interchangeably. --ar seems a bit more common in practice.

The aspect ratio can go anywhere in your prompt, but the end keeps it cleanly separated. Make sure to leave a space before the parameter.

Now for an expert Midjourney user tip: You can define any crazy aspect ratio you want, but Midjourney may not always match it perfectly.

In my experience, it will get very close to standard ratios like 16:9 or 9:16. But for something more extreme like 100:9, your actual generated image may be more like 30:9.

Still, specifying the ratio upfront is way better than leaving it to chance! Let‘s look at which ratios work best.

Over my many Midjourney creations, I‘ve compiled data on which aspect ratios generate the best results for different use cases:


A square image is perfect for:

  • Profile pictures
  • Logos
  • Album art
  • Facebook/Instagram posts

Square formats feel stable, compact, and well-balanced.


The widescreen HD video ratio works great for:

  • YouTube thumbnails and videos
  • Digital ads
  • Website headers
  • Cinematic scenes

16:9 adds scope, impact, and energy.


The smartphone portrait ratio is ideal for:

  • Instagram stories and feed posts
  • Product photography
  • Visual social content

Its vertical shape feels innate to mobile users.


This slightly narrower ratio can work nicely for:

  • Portrait shots
  • Visual art
  • More vertical compositions

The proportions are a bit more graceful than 16:9 landscapes.

Odd Dimensional Art

Don‘t be afraid to experiment with unconventional ratios like 4:9, 10:3, or 21:13 for abstract art pieces!

Really think about the feeling you want to evoke, and choose an aspect ratio to match it. The possibilities are endless.

Troubleshooting Midjourney‘s Aspect Handling

Midjourney can sometimes miss the mark on nailing your specified aspect ratio. Here are some pro troubleshooting tips:

  • Double check prompt formatting – no typos in the --ar parameter?

  • Try generating multiple versions – you may get lucky on a 2nd or 3rd attempt.

  • Simplify the prompt – remove extra details so Midjourney focuses just on the subject and frame.

  • Get more specific with composition – describe exactly what should be in the scene.

  • Rephrase your language – small variations in wording can make a difference.

  • Slightly adjust the ratio – bump 16:9 to 16:10 if needed.

  • Use Upscale and external editing to fix the ratio as a last resort.

With experience, you‘ll learn how to coax Midjourney into nailing the perfect aspect ratio every time.

My Aspect Ratio Design Process + Tips

After much Midjourney experimentation, here is my proven workflow for aspect ratio success:

  1. First, decide where the image will be used – YouTube, Instagram, etc. Look up the ideal ratio for that medium.

  2. Incorporate the aspect parameter into my prompt using --ar or --aspect. I put it at the end for clarity.

  3. Keep my prompt concise so Midjourney focuses on the aspect ratio guidance.

  4. Generate the image! I may tweak wording and retry if needed.

  5. For important images, I‘ll generate 3-5 versions to select the best composition.

  6. As a last resort, I may resize in Photoshop if Midjourney‘s ratio is slightly off.

Here are a few pro tips I‘ve picked up:

  • Get in an "aspect ratio mindset" – think about orientation as you compose prompts.

  • Frame shots intentionally – describe the scene‘s position in the frame.

  • Use background colors and landscapes to reinforce proportions.

  • For key images, I‘ll run A/B tests of different ratios.

  • Odd dimensions can create unique art – don‘t just stick to the common ratios!

  • Occasionally break the "rules" – like vertical portraits for YouTube thumbnails to stand out.

With this adaptable prompting process and growth mindset, you can master every type of aspect ratio for your needs.

Comparing Midjourney‘s Ratios to Dall-E and Stable Diffusion

Midjourney is not the only AI game in town – tools like Dall-E 2 and Stable Diffusion also allow you to specify custom aspect ratios.

Here is how Midjourney compares based on my testing:

  • Dall-E 2 also uses --ar but seems to adhere more strictly to exact ratios defined.

  • Stable Diffusion involves adding resize_to_fill parameters which isn‘t as intuitive.

  • Midjourney may take more coaxing and retries to match a given aspect ratio.

  • But Midjourney‘s artistic style and abstraction make odd dimensions shine.

  • Overall Midjourney strikes a great balance between control and surprise.

So while the other AI options work fine, Midjourney still stands out in how it empowers aspect ratio possibilities.

Final Thoughts and Expert Advise

Aspect ratio is a make-or-break artistic choice for visual content creation. By mastering aspect ratio prompting in Midjourney, you gain a superpower over image shape and composition.

My advice is to always keep aspect ratio top of mind as you conjure up prompts. Visualize the orientation you want, and let Midjourney materialize it.

This opens up so many new creative directions before even generating a single pixel.

Understanding fundamental image principles like aspect ratio is key to elevating from novice to expert Midjourney user.

So pay attention to ratios, intentionally craft your prompts, and your AI art will transport viewers – no matter the dimensions!

What will you imagine next?

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