Fit a video for Reels, TikTok and YouTube on your Mac
By Himanshu Ranjan · Updated 8 November 2026
To fit a video for Reels, TikTok or Stories on your Mac, select it in Finder, hold the right Option (⌥) key and choose Frame › Fit for Stories, Reels & TikTok (9:16). For YouTube choose Frame › Fit for YouTube (16:9); for the Instagram feed, 4:5 or 1:1. FileDial saves a new copy beside the original, on your Mac, with nothing uploaded.
How to do it with FileDial
- Select the video in Finder.
- Hold right ⌥ to open the dial.
- Choose Frame › Fit for Stories, Reels & TikTok (9:16), or the 16:9, 4:5 or 1:1 option.
- Preview the new copy beside the original; press Undo and pick another shape if it doesn't suit.
Your original file stays untouched. The result is saved beside it, and every result has Undo.
Which option to pick
| Tool | Use it when |
|---|---|
| Fit for Stories, Reels & TikTok (9:16)Frame | Posting full-screen vertical video: Instagram Stories and Reels, TikTok and other vertical feeds. |
| Fit for YouTube (16:9)Frame | Uploading to YouTube or anywhere widescreen, such as slides, websites and TVs. |
| Fit for Instagram feed (4:5)Frame | A portrait post in the Instagram feed that takes up more screen than a square. |
| Fit for Instagram square (1:1)Frame | A square post, or a shape that sits well in grids and most social feeds. |
Aspect ratios for each platform
Aspect ratio is the shape of the frame, width to height. Cameras and screen recorders usually produce 16:9 landscape video, while phones held upright record 9:16. Each platform is built around particular shapes, and a video in the wrong one gets cropped by the app, shown small with bars, or rejected.
Vertical 9:16 fills a phone screen and is the native shape for Stories, Reels and TikTok. Widescreen 16:9 is the standard for YouTube and for anything watched on a laptop or TV. In the Instagram feed, 4:5 portrait takes up more of the screen than a square, while 1:1 is the classic square that works almost anywhere.
Changing the shape always means a trade-off between cropping some of the picture and adding space around it. Before you publish, watch the new copy to make sure faces, captions and text sit where you want them, and use Undo to try another ratio.
- Stories, Reels, TikTok: 9:16.
- YouTube and widescreen: 16:9.
- Instagram feed portrait: 4:5.
- Square posts: 1:1.
Why not resize a video with an online tool
Online resizers want the full video uploaded before they do anything. Social clips are often filmed at home, at work or of people who never agreed to their footage sitting on a third party's server, and big files take a long time to upload over home connections.
Free converter sites have a security record to consider. On 7 March 2025 the FBI Denver Field Office warned that free online document converter tools are increasingly used to spread malware. The conversions work, but the returned files can carry malware that leads to ransomware, and the sites can scrape personal data such as identity numbers, banking and crypto details, emails and passwords. The warning was about document converters, though online video tools use the same upload-and-download approach.
FileDial reframes the video on your Mac. Nothing is uploaded, and it works with Wi‑Fi off.
Other ways to change a video's shape on a Mac
iMovie and other video editors can reframe footage, with control over cropping and positioning, though setting up a project takes longer than a single click. The Photos app has crop tools for videos in your library. QuickTime Player can trim and change resolution on export, but it does not change the aspect ratio.
FileDial is faster when you want a ready-made shape for a known platform straight from Finder, the same preset every time, several videos reframed in one batch, and Undo when a framing doesn't work.
Questions
Which option should I use for Instagram Reels?
Use Frame › Fit for Stories, Reels & TikTok (9:16). It produces the vertical shape Reels, Stories and TikTok are built around. For a regular feed post, use the 4:5 or 1:1 option.
Does it change my original video?
No. Each Frame tool saves a new copy beside the original, which stays as it was. You can press Undo on any result and try a different shape.
Can I make several versions for different platforms?
Yes. Run the 9:16, 16:9, 4:5 and 1:1 tools one after another on the same video. Each one saves its own new copy beside the original.
Is my video uploaded?
No. Every FileDial tool runs on your Mac and files are never uploaded. All tools work with Wi‑Fi off, so footage of friends, family or clients stays on your Mac until you choose to post it.
Can I also make the file smaller for posting?
Yes. After fitting the frame, select the new copy and choose a compress option such as Compress › Compress to 720p. You can chain both steps in a recipe to reuse them.