> Quick answer: Use 4:5 (1440x1800 px) for maximum mobile impact or 1:1 (1080x1080 px) for cross-placement flexibility. JPG or PNG only. Max 30MB. Min 500px wide. Resize first, upload second.
Wrong dimensions get your ad rejected before it ever runs. Or worse, it runs cropped and looks unprofessional to your audience. Here's exactly what you need and how to fix it fast.
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Instagram Feed Ad Dimensions at a Glance
Get these numbers right before you touch anything else. Per Meta's Ads Guide, Instagram Feed image ads have two primary formats and a short list of hard requirements.
Recommended size: 4:5 aspect ratio (1440x1800 pixels)
The 4:5 ratio is Meta's top recommendation for Feed ads. At 1440x1800 pixels, it fills a significant portion of the mobile screen. A lighter alternative, 1080x1350 pixels, hits the same 4:5 ratio with a smaller file size. Both work.
Square alternative: 1:1 aspect ratio (1080x1080 pixels)
Square ads run cleanly across roughly 80% of Meta placements without automatic cropping. If you want one creative that works everywhere, 1:1 is the safer pick.
Why aspect ratio matters for mobile viewing
Instagram's Feed is overwhelmingly mobile. A taller image occupies more scroll space and holds a viewer's attention longer. Get the ratio wrong and Meta either rejects the ad or crops it automatically. Neither outcome is good for your campaign.
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Step-by-Step: How to Resize an Image for Instagram Feed Ads
Follow these five steps from checking your current dimensions to uploading a clean, spec-compliant file.
Step 1: Determine your target aspect ratio (4:5 vs 1:1)
Decide before you open any tool. Choose 4:5 for maximum mobile real estate. Choose 1:1 for flexibility across placements. Both are valid. The right pick depends on your campaign goal.
Step 2: Check your image's current dimensions and aspect ratio
Right-click the image file and open its properties. You'll see width and height in pixels. Divide the height by the width to calculate the ratio. If it doesn't match 4:5 or 1:1, a resize is required before uploading.
Step 3: Use Smart Resize to auto-resize while maintaining quality
Coinis Revise includes Smart Resize. Drop your image in, select your target ratio, and it crops and scales automatically. No manual math. No quality loss from over-compression. Cutting-edge AI models handle the output.
Step 4: Preview your resized image before uploading
Study the preview before moving on. Confirm that key visual elements, your product, a face, a headline, are not cut off at the edges. If something is too close to the crop line, use the Edit text on image tool in Revise to reposition text or elements.
Step 5: Upload to Meta Ads Manager or your campaign tool
Head to Meta Ads Manager, create your ad, and upload the resized JPG or PNG. Meta validates dimensions on upload and flags anything outside the accepted range immediately.
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Key Technical Specifications
Per Meta's Ads Guide, these are the hard technical requirements for Instagram Feed image ads.
Supported file formats (JPG, PNG)
Only JPG and PNG are accepted. WebP, GIF, and SVG are not supported for this placement.
File size limits and minimum width requirements
Maximum file size is 30MB. Minimum image width is 500 pixels. Staying at or above 1080 pixels wide keeps your creative sharp on high-resolution phone screens.
Aspect ratio tolerance and why precision matters
Meta's maximum allowed aspect ratio is 191:100 (approximately 1.91:1 landscape). Go outside the accepted range in either direction and Meta rejects the submission. Stick to 4:5, 1:1, or 1.91:1 to stay within bounds.
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Why 4:5 vs. 1:1: Which Should You Choose?
Both formats run in the Feed. The difference is meaningful.
4:5 fills more mobile screen space, higher engagement potential
A 4:5 ad takes up noticeably more vertical space on a phone screen. That extra space buys more time in front of your audience before they scroll past.
1:1 square works for ~80% of placements, more flexible
Square runs across Feed, Marketplace, and other Meta surfaces without automatic cropping. If you're running a broad campaign and don't want to manage multiple creative sizes, 1:1 is practical.
Testing both to find what resonates with your audience
Run both ratios as separate ad sets. Review performance in Meta Ads Manager after a few days. Let the data decide, not assumptions.
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Common Resize Mistakes to Avoid
Small errors here waste real budget.
Stretching instead of cropping to fit aspect ratio
Stretching distorts your image. Faces look wrong. Products look off. It damages trust immediately. Always crop or recompose. Never stretch to fill a ratio.
Using dimensions outside Meta's technical requirements
Anything below 500px wide or beyond the 191:100 maximum aspect ratio will be flagged at upload. Check your dimensions before you get to that screen.
Forgetting to account for text overlay space
Meta caps primary text at 125 characters and headlines at 40 characters. Leave clear visual space in your creative for both. A tight crop can push your product into your call-to-action and make the whole ad unreadable.
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Use Coinis Smart Resize to Skip Manual Resizing
One-click resize for any Instagram format
Smart Resize in Coinis Revise detects your image dimensions and scales to any target ratio. No calculation. No guessing.
Maintains image quality while hitting exact specifications
Revise uses cutting-edge AI models to sharpen and refine as it resizes. Your creative stays clean at any output size, whether you're going 4:5 or 1:1.
Save time and recreate variations for A/B testing
Need a 4:5 and a 1:1 version of the same ad? Generate both in seconds. More format variations mean faster testing and better data.
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Or skip the steps.
Coinis Revise edits any ad image with AI. Move text. Change text. Swap colors. Erase objects. Translate to any language. One click each.
No design skills. No Photoshop. One click.
15 AI tokens a month. No credit card.
Frequently Asked Questions
What is the best image size for an Instagram Feed ad?
Meta recommends 4:5 aspect ratio at 1440x1800 pixels for Instagram Feed image ads. This size fills the most mobile screen space. If you want a format that runs across more placements without cropping, use 1:1 square at 1080x1080 pixels.
What file formats does Instagram accept for Feed ads?
Instagram Feed ads accept JPG and PNG only. The maximum file size is 30MB and the minimum image width is 500 pixels.
What happens if my image is the wrong aspect ratio?
Meta will either reject the ad at upload or automatically crop it to fit the allowed range. Either way, your creative won't display as intended. Always resize to the correct ratio before uploading.
Can I use the same image for both 4:5 and 1:1 formats?
Yes, but you'll need two separate resized versions. A 4:5 crop and a 1:1 crop from the same source image will look different. Use Smart Resize in Coinis Revise to generate both in seconds and run them as separate ad sets for testing.