How to Make Instagram Posts with Mixed Sizes

Want to break free from the uniform square grid on Instagram? Combining different photo and video sizes in a single carousel post can make your content instantly more dynamic and memorable. This guide provides a straightforward method for creating visually engaging mixed-size posts, covering everything from the simple strategy behind it to the step-by-step process using tools you probably already use.

Why Use Mixed-Size Instagram Posts?

While a perfectly uniform grid can be aesthetically pleasing, breaking the pattern with intentional variety can have a big impact. When users are scrolling through a sea of sameness, something a little different forces them to pause.

• Better Visual Storytelling: Varying the aspect ratio of your media allows you to guide the viewer’s attention and tell a more powerful story. Imagine a stunning wide landscape photo setting the scene, followed immediately by a tight, vertical detail shot. This combination tells a richer story than two identically cropped photos ever could.
• Increased User Engagement: A carousel that mixes full-bleed portraits with smaller, centered images on colored backgrounds is more likely to stop the scroll. This visual intrigue encourages people to swipe through all your slides to see what comes next, boosting your post's engagement metrics.
• More Creative Freedom: You're no longer forced to crop your beautiful landscape photo into a tight portrait or awkwardly zoom into a photo to make it fit a square. This method gives you the freedom to showcase your work - whether it’s photography, design, or a product shot - in its intended format without compromises.

Understanding Instagram's Carousel Rules

Before jumping into the "how-to," it's important to understand a key limitation of Instagram carousels. While you can upload images of different sizes into a single carousel, Instagram doesn't actually display them in their original dimensions. Instead, it forces a single aspect ratio on the entire post.

The entire carousel's aspect ratio is determined by the size and shape of your very first slide.

Here’s how that plays out:

• If your first image is a 1:1 square, every subsequent image - even if you uploaded it as a 4:5 portrait - will be cropped and displayed as a 1:1 square in the feed.
• If your first image is a 4:5 portrait (the tallest format allowed), every subsequent image will be displayed inside a 4:5 frame.
• If your first image is a 1.91:1 landscape (the widest format allowed), every image after it will get cropped into that wide, shorter frame.

So, the secret isn't actually posting different sizes directly. It's about creating the illusion of different sizes by placing your varying assets onto a single, consistent canvas that works for every slide.

The Winning Strategy: The "Consistent Canvas" Method

The solution is refreshingly simple: you establish one canvas size for your entire carousel and then place your images and videos of different dimensions onto that background. This means every slide you export is technically the same size, but the content inside it appears to vary.

To get the most screen real estate, you should almost always use the 4:5 portrait aspect ratio (1080 pixels wide by 1350 pixels tall) as your master canvas for every slide. By starting with this tall format for your first slide, you signal to Instagram that the entire carousel should use this size, giving you the maximum vertical space to play with.

When you have a photo that's a square or a landscape, you simply place it onto a 1080x1350 background. The "empty" space around the image becomes part of the slide, often filled with a brand color, a subtle gradient, or just clean white space.

Step-by-Step Guide: How to Create a Mixed-Size Carousel

Ready to build one yourself? Here’s a breakdown of the process using a couple of popular design tools.

Step 1: Choose Your Master Aspect Ratio

Start your project using a 1080px by 1350px canvas. This 4:5 ratio gives you the most visibility in the mobile feed. If you make this your standard for every single slide in the carousel, you'll never have to worry about Instagram awkwardly cropping your content.

Step 2: Plan Your Carousel Slides

Before you open any app, quickly map out the content for your carousel. A little planning helps the final post feel cohesive and intentional, rather than a random assortment of photos. Here’s a sample plan for a five-slide carousel:

• Slide 1: Main hero shot. A full-bleed 4:5 portrait photo that fills the entire 1080x1350 canvas. This is your hook.
• Slide 2: A contextual landscape photo. Place this wider photo in the center of a new 1080x1350 canvas, leaving space above and below.
• Slide 3: A 1:1 square detail shot. Center this square photo on another 1080x1350 canvas.
• Slide 4: A side-by-side comparison. Place two smaller vertical images next to each other on the 1080x1350 canvas.
• Slide 5: Call-to-action or final image. This could be another full-bleed portrait or a graphic with text.

Step 3: Pick Your Tool and Build the Slides

You can use pretty much any design software for this, from free mobile apps to professional desktop programs. The process is nearly identical across all of them.

Using Canva (The Easiest Option)

Canva is perfect for this, as it's built around a multi-page design format that mimics a carousel.

1. On the Canva home screen, click "Create a design" and select "Custom size." Enter 1080 for the width and 1350 for the height.
2. This creates your first slide (your 4:5 canvas). Upload your "hero shot" and drag it to fill the entire page.
3. Click "Add page" below your first design to create the second slide. This new page is also 1080x1350.
4. Click on the new page and set a background color. Choose a brand color, black, or white for a clean, cohesive look.
5. Now, upload your landscape or square photo. Drag it onto a new page, but don't drop it into the background. Instead, position and resize it in the middle of your colored canvas.
6. Repeat this process for all your slides. For side-by-side images, just place and resize two photos next to each other on a blank page.
7. When you're finished, click "Share," then "Download." Make sure your file type is PNG or JPG and select "Download pages as separate files." Canva will give you a ZIP file containing each slide as an individual image, ready for Instagram.

Using Adobe Photoshop (For More Control)

If you're a Photoshop user, the artboards feature makes this process a breeze.

1. Go to File > New. Set the dimensions to 1080 x 1350 pixels and be sure to check the "Artboards" box.
2. You now have your first artboard. You can place your full-bleed 4:5 image here.
3. To add more slides, select the Artboard Tool (or press Shift+V) and click the little plus (+) icon that appears next to your artboard. This will create another 1080x1350 artboard right beside it. Create one artboard for each slide in your carousel.
4. For the slides with smaller images, first fill the artboard's background with your desired color. Then, drag your landscape or square image onto that artboard as a new layer. Use the transform tools (Ctrl/Cmd+T) to resize and center it.
5. Once all your artboards are designed, go to File > Export > Artboards to Files. This will save each artboard as a high-quality, perfectly-sized PNG or JPG.

Creative Ideas for Mixed-Size Posts

Now that you know the technique, here are a few ideas to get you started:

• The Enhanced Photo Dump: Start with a strong, full-bleed portrait. Follow it with slides that contain smaller widescreen and square shots from the same event, using a consistent brand color in the background. This feels more polished and curated than a standard photo dump.
• The Product Showcase: Use a full-size 4:5 shot of your product for the first slide. On the next slides, place landscape photos of the product in use, using the extra canvas space above and below for text callouts about features or benefits.
• Tell a Story with Text: The space around your smaller photos is prime real estate. Use it to add captions, ask questions, or provide context a traditional caption can't. This turns a simple image into an infographic.
• Before-and-After Transformations: Place two thin vertical 'before' and 'after' photos side-by-side on a single 4:5 canvas. This is a powerful, visually compelling format that's perfect for service providers, artists, or fitness coaches.

A Few Final Tips for Success

• Stay Consistent: Use the same background color for all slides that have one. This consistency ties the entire carousel together and makes it feel professional.
• Mind the Safe Zones: Instagram adds UI elements like the 'Send Message' button or your username at the bottom of posts. Keep important text or visual elements away from the very bottom edge of your 1080x1350 canvas.
• Lead with Your Best 4:5: Always, always make sure your first slide is your best photo and that you export it as a 1080x1350 image. This sets the dimensions for everything that follows and grabs attention on the Explore page.
• Handle Videos the Same Way: The same principle applies to videos. If you have a widescreen video, place it on a 1080x1350 canvas in a video editor like CapCut or inside Canva, and export the entire 4:5 framed video.

Final Thoughts

Creating impressive mixed-size carousels on Instagram isn't about using a secret feature, it's about understanding the platform's constraints and working creatively within them. By using a single, consistent 4:5 canvas as your foundation, you can artfully arrange photos and videos of all shapes and sizes to tell more engaging stories and stop the scroll.

Planning this kind of visual content can get complex, especially when you're managing multiple social profiles. At Postbase, we designed our visual calendar to give you a clear, bird's-eye view of your entire content strategy. You can see how your carousels, Reels, and Stories fit together, drag and drop posts to reschedule them in seconds, and keep your feed looking intentional and professional without the extra headache.