GoPro Action & Extreme Sport Resizer

Confused by 9:16 vs 4:5? Here is the definitive guide to social media dimensions:

9:16 (Vertical / Portrait): The new gold standard. Resolution: 1080x1920. Used for: TikTok, Instagram Reels, YouTube Shorts, Snapchat, Facebook Stories. If you want to go viral, this is the format.

16:9 (Landscape / Widescreen): The cinema standard. Resolution: 1920x1080. Used for: YouTube Long-form, LinkedIn Desktop, Facebook Video, TV, and Cinema. This is how most cameras film naturally.

1:1 (Square): The classic format. Resolution: 1080x1080. Used for: Instagram Feed, Facebook Feed, LinkedIn Mobile. Square takes up 78% more screen space on a phone than landscape videos.

4:5 (Vertical Crop): The 'Instagram Portrait'. Resolution: 1080x1350. This is the tallest aspect ratio allowed on the Instagram Feed. It takes up the maximum amount of vertical screen real estate without being full-screen 'Stories' mode.

21:9 (Ultrawide): Used for cinematic film trailers. Resolution: 2560x1080. Rarely used on social media but looks incredible on gaming monitors.

When changing a video's shape (e.g., from wide to tall), you have a critical creative choice to make. Reelic gives you control over this.

1. Fit (Letterbox / Padding): This method ensures that 100% of your original video is visible. If you put a wide video into a tall frame, there will be empty space at the top and bottom. We fill this space with black bars (classic cinematic look) or a blurred version of the video (modern 'canvas' look). This is best when you have text or graphics on the edges that cannot be cut off.

2. Fill (Crop / Zoom): This method zooms in on the center of your video until it fills the entire screen. The edges are chopped off. This creates a much more immersive experience and is preferred for TikTok/Reels, but you lose the sides of your image. If your subject is in the center, this is usually the best option.

The Reelic Approach: Our current tool defaults to a smart 'Fit' to ensure you never lose content, but we are adding intelligent cropping features soon that let you pan and scan your footage.

The smartest creators don't film three times. They film once and edit three times.

The Strategy: Shoot your main content in high-quality 4K landscape (16:9). This is your 'master' file for YouTube.

Step 1: Upload the master file to Reelic's Resizer.

Step 2: Select '9:16' to create a version for TikTok/Shorts. Use this to tease the main video.

Step 3: Select '1:1' to create a square version for your LinkedIn or Twitter feed.

Result: One shoot, three pieces of content, three distinct audiences reached. This is how GaryVee and Hormozi scale their content empires.

We love professional editing software like Adobe Premiere or DaVinci Resolve, but for simple resizing, they are overkill.

Scenario: You have a finished video and just need to make it square for Instagram.

In Premiere: Open app (3 mins) -> Create new sequence -> Check settings -> Import video -> Drag to timeline -> Go to Sequence Settings -> Change math to 1080x1080 -> Scale video -> Export Media -> Choose Codec -> Wait for render.

In Reelic: distinct Open browser -> Drag video -> Click 'Square' -> Download. Done.

Our tool removes the 'friction' from the process. It runs on Chromebooks, work laptops where you can't install software, and even tablets.

Under the hood, Reelic uses FFmpeg's powerful scaling filters.

Lanczos Resampling: When we resize your video, we don't just delete pixels. We use the Lanczos algorithm to mathematically calculate the new pixels. This keeps lines sharp and text readable, even when downscaling.

Padding Math: When adding black bars, we calculate the exact pixel dimensions to ensure the video is perfectly centered. No weird 1-pixel off-center issues.

Container Update: We rewrite the MP4 container header to explicitly state the new resolution (e.g., 'width: 1080, height: 1920'). This ensures that when you upload to Instagram, the app instantly recognizes it as a Reel and doesn't try to stretch it.

For TikTok: Always resize to 9:16. If you upload landscape, viewers have to turn their phones (they won't) or watch a tiny video. 9:16 videos account for 98% of viral content.

For LinkedIn: Square (1:1) is the secret weapon. It takes up more vertical space in the desktop feed than landscape, and looks great on mobile too. It is the most 'professional' versatile format.

For Twitter/X: Landscape (16:9) is still standard here, but Square (1:1) is gaining traction. Vertical video often gets cropped awkwardly in the feed preview.

For Instagram: If posting to the Grid, use 4:5. If posting to Reels, must use 9:16. If posting to Stories, 9:16 also.