Instagram isn't one thing. It's four overlapping content channels, and each one reaches people differently. Feed posts are your permanent content. Reels get distributed to people who don't follow you. Stories reach your existing followers and disappear after 24 hours.

Here's exactly how to publish each one, with the specs you need and the rules that changed in 2026.

Feed posts: photos and carousels

Feed posts are the permanent content on your profile. They show up in hashtag and Explore results, and they're what new visitors scroll through when they land on your page.

Image sizes for Feed

  • Square: 1080 x 1080 pixels (1:1 aspect ratio)
  • Portrait (recommended): 1080 x 1350 pixels (4:5 aspect ratio)
  • Landscape: 1080 x 566 pixels

The portrait 4:5 format (1080 x 1350) is now the safest default for Feed. It takes up more vertical space, which means more screen real estate for your content, and it displays correctly in both the feed and the profile grid.

Carousels

Carousels (multiple images or videos in one post) consistently outperform single images for engagement. Every swipe is a positive signal that says "this content is worth viewing". You can include up to 20 photos or videos in a single carousel.

Reels: short-form video

Reels are the fastest-growing format on Instagram. They get distributed to people who don't follow you through the Reels tab, Explore page, and main feed — no other format gives you organic reach to cold audiences the same way.

Reels specs

  • Size: 1080 x 1920 pixels (9:16 aspect ratio)
  • Length: Up to 20 minutes, but under 3 minutes for maximum discovery
  • Optimal length: 15–45 seconds for most content
  • Cover image: Upload at 1080 x 1920 pixels, same 9:16 ratio

Hook within the first 2 seconds. Add on-screen text because most people watch without sound. And use 3–5 hashtags, not 30.

Stories: ephemeral content

Stories reach your existing followers and disappear after 24 hours. They're for behind-the-scenes moments, polls, and casual updates that don't need to live on your profile forever.

Stories specs

  • Size: 1080 x 1920 pixels (9:16 aspect ratio)
  • Length: Up to 60 seconds per Story segment

The new hashtag rules

Instagram enforced a hard 5-hashtag limit on posts and Reels in December 2025. It's a platform-enforced limit, not a best practice recommendation, and it applies globally across all account types.

This means every hashtag slot counts. The strongest strategy in 2026 uses a deliberate mix:

  • 1–2 niche community hashtags — specific to your topic, with 10K–500K posts. Mid-tier hashtags consistently outperform mega-tags because your content can actually compete there.
  • 1 branded hashtag — your own community tag.
  • 1–2 topic hashtags — broader tags that describe your content category.
  • 1 format hashtag — like #reels or #carousel.

Hashtags now function as content classification signals for Instagram's algorithm, not standalone reach drivers. Content quality, watch time, and engagement behavior carry more weight than hashtags. Choose the right five, and you're giving Instagram precise context to recommend your content to the right non-followers. Choose the wrong five, and you're wasting the only slots you have.

What to do with this

Use 1080 x 1350 for Feed posts, 1080 x 1920 for Reels and Stories. Keep Reels under 3 minutes and hook in the first 2 seconds. Pick 3–5 highly relevant hashtags — niche community, branded, topic, and format. And remember: hashtags classify your content, they don't carry it. The content itself still does the heavy lifting.

Next: read how the Reels algorithm works in detail, or learn how to switch to a business account.