How to Resize an Image in Photoshop for Instagram

Getting your images to look tack-sharp on Instagram starts with resizing them correctly in Photoshop before you even think about posting. When you upload an image that's too big or the wrong shape, Instagram's heavy-handed compression algorithm goes to work, often leaving you with a blurry, pixelated result. This guide will walk you through the entire Photoshop process, covering the best dimensions for every type of post and the exact steps to crop, resize, and export images that look pristine in the feed.

Why Proper Sizing for Instagram is a Big Deal

Ever posted a photo that looked amazing on your computer, only to find it looks soft and low-quality on Instagram? That's almost always a sizing issue. Think of it this way: Instagram has a "preferred" set of dimensions it wants you to use. When you feed it an oversized image, the platform has to force it to fit, and that forced resizing is rarely pretty. The result is a loss of detail and sharpness.

By preparing your images in Photoshop ahead of time, you take back control. You decide what the final dimensions are, how the image is sharpened for the screen, and how much compression is applied. This not only keeps your images looking crisp but also helps create a professional and consistent visual brand. A feed filled with perfectly formatted visuals just looks more polished and intentional - something that followers and potential collaborators definitely notice.

It's all about playing by Instagram's rules to get the best possible result. Hand over a perfectly sized image, and the platform's compression has much less work to do, leaving your photo looking just as you intended.

The Easiest Instagram Dimensions Cheat Sheet

Before jumping into Photoshop, you need to know what you're aiming for. Resolutions and aspect ratios can be confusing, but for Instagram, it really comes down to a few key numbers. Here are the ones that matter today.

1. Instagram Feed Posts

Your main feed is where you have the most flexibility, though one option stands out as the best for engagement.

• Portrait (4:5 Ratio): At 1080 x 1350 pixels, this format is the top choice for marketers and creators. Why? It takes up the most vertical space on a phone screen, grabbing more attention as users scroll. If you want to maximize your impact, this is the size to use.
• Square (1:1 Ratio): The classic Instagram format. Size your image to 1080 x 1080 pixels. It's a safe, clean choice that always works well, especially for profile images and graphic-heavy posts.
• Landscape (1.91:1 Ratio): This horizontal format should be used sparingly. At 1080 x 566 pixels, it takes up the least amount of screen real estate. Reserve it for wide panoramic shots that absolutely cannot be cropped.

2. Instagram Stories & Reels (9:16 Ratio)

Vertical content is king. For both Stories and Reels, the dimensions are the standard full-screen size: 1080 x 1920 pixels. Filling the entire screen with your visuals creates a much more immersive experience for viewers, so always design your temporary content in this native format.

3. Carousel Posts

Carousels follow the same aspect ratio rules as regular feed posts - you can choose between Portrait (4:5) or Square (1:1). The most important rule for carousels is consistency. Pick one aspect ratio and make sure every single slide in the carousel matches it. A mix of portrait and square images will be awkwardly cropped by the app, so stick to one size throughout.

How to Resize an Image for Instagram: The Step-by-Step Photoshop Workflow

Now that you know your target dimensions, it's time to get a process down in Photoshop. Following these steps in order will give you a perfectly optimized image every time.

Step 1: Open Your Image & Work Non-Destructively

First, open your image in Photoshop. Before you do anything else, create a duplicate layer. You can do this by dragging your background layer to the "New Layer" icon (the little plus sign) in the Layers panel or by using the keyboard shortcut Cmd+J (on Mac) or Ctrl+J (on Windows).

Working on a separate layer is a fundamental habit. It means your original image remains untouched, so you can always go back and start over without reopening the file if you make a mistake.

Step 2: Use the Crop Tool to Set the Aspect Ratio

This is probably the most overlooked step, but it's where you define the shape of your final image. Many people jump straight to the "Image Size" dialog, but that just shrinks or stretches your photo. You first need to crop it to the correct aspect ratio.

1. Select the Crop Tool from the toolbar on the left (or press the "C" key).
2. In the top toolbar, you'll see a dropdown menu that probably says "Ratio." Click it.
3. You can either select a preset or type in your own custom ratio. For a portrait post, type "4" in the first box and "5" in the second. For a square post, type "1" and "1".
4. A crop box will appear over your image. You can now click and drag your image within this box to adjust the composition. Reposition the frame until it looks perfect.
5. Once you're happy with the composition, hit Enter or click the checkmark in the top toolbar to apply the crop.

Step 3: Use "Image Size" for Final Pixel Dimensions

Now that your image has the right shape, it's time to set the final size in pixels. This is where you tell Photoshop the exact dimensions recommended by Instagram.

1. Go to the menu bar and select Image > Image Size... (Shortcut: Opt+Cmd+I on Mac or Alt+Ctrl+I on Windows).
2. An "Image Size" dialog box will pop up with several important settings.
3. Dimensions: Make sure the dimensions are set to "Pixels." Since you have already locked your aspect ratio with the crop tool, you only need to change one value. For a 4:5 portrait post, type 1080 into the "Width" box. The "Height" should automatically update to 1350.
4. Resolution: Set this to 72 Pixels/Inch. This is the standard resolution for web and screen viewing. It doesn't hurt to use a higher resolution, but it adds unnecessary file size for the web.
5. Resample: Make sure the "Resample" box is checked. To actually change the number of pixels, this must be on. Next to it, there's a dropdown menu with different resampling algorithms. Choose Bicubic Sharper (Reduction). This algorithm is specifically designed for making images smaller (downsizing) and does a great job of preserving detail.
6. Click "OK" to apply the resize. Your image is now the perfect size for Instagram.

Step 4: A Quick Sharpen for the Web (Highly Recommended)

Whenever you downsize an image, it tends to lose a tiny bit of its original crispness. A final touch of sharpening can bring that detail back and make your photo pop on mobile screens. Just don't overdo it.

A safe and effective method is using the Unsharp Mask:

1. Go to Filter > Sharpen > Unsharp Mask...
2. Zoom in on your image to 100% so you can see the effect clearly.
3. Use these settings as a gentle starting point:
   • Amount: 80-120%
   • Radius: 0.3-0.5 pixels
   • Threshold: 2-4 levels
4. Toggle the "Preview" checkbox on and off to see the before and after. The effect should be subtle - you just want to see the details get a little crisper, not create heavy, ugly halos around edges. Adjust the settings until it looks right, then click "OK."

The Best Photoshop Export Settings for Instagram

Your job isn't done yet! How you export your resized image is just as important as the resize itself. Using the wrong settings can ruin all your hard work by introducing compression artifacts or shifting colors.

The "Export As" function is the modern, preferred way to save for the web.

1. Go to File > Export > Export As...
2. In the dialogue box that pops up on the right, configure your settings:
   • Format: Set this to JPG. JPG is the best format for photos, PNG creates much larger files and is best suited for graphics that require transparency.
   • Quality: You don't need to push this to 100%. A quality setting between 76% to 85% is the perfect balance. It keeps the file size down while preserving visual quality, which gives Instagram less reason to apply its own heavy compression.
   • Image Size: Double-check that your dimensions (e.g., 1080 x 1350) are still correct.
   • Color Space: This setting is vital. Make sure both "Convert to sRGB" and "Embed Color Profile" are checked. Instagram operates in the sRGB color space. If your image is in another profile like Adobe RGB, the colors will look dull and washed out once you upload it. Checking these boxes ensures your colors look accurate in the app.
3. Click "Export All" and choose a logical name for your new file, like `your_image_name-IG-Portrait.jpg`. You're now ready to post!

Final Thoughts

Nailing your visuals on Instagram is a simple process once you understand it: Crop for aspect ratio first, resize for pixel dimensions second, then fine-tune with sharpening and export with the right sRGB settings. It might feel like a few extra steps, but taking control of this process in Photoshop - instead of letting Instagram's algorithms make decisions for you - ensures your content always looks its best.

Of course, creating stunning visuals is just step one. The next challenge is actually planning and scheduling all of that content in a way that feels organized and stress-free. After preparing our own content, we at Postbase use our own visual calendar to solve this. We drag-and-drop finished Reels, Stories, and images into place on the calendar, get a bird's-eye view of what's coming up, and schedule everything in batches, freeing us up from having to think about it every day. It takes the headache out of staying consistent and lets us focus on making more great content.