How-to

How to edit vertical video on iPhone (Reels, TikTok, Shorts)

A practical guide to editing vertical 9:16 video on iPhone — from import to caption export — with the on-device workflows that work for Instagram Reels, TikTok, and YouTube Shorts.

7 min read

Vertical video is no longer the future — it is the present. Instagram Reels, TikTok, YouTube Shorts, Snapchat, and Pinterest all serve vertical 9:16 video first. If you are shooting on iPhone, the cleanest workflow is to edit the vertical video on iPhone too. No round-trip through a laptop, no upload, no waiting for a render.

This guide walks through the on-device workflow for editing vertical video — from import to caption export to post — with the settings that work for all three platforms.

Vertical video specs in 2026

All three short-form platforms converge on the same aspect ratio:

Two ways to start: shoot vertical or shoot horizontal

Option A: Shoot vertical (recommended for native feel)

Hold the iPhone vertically (portrait orientation) and shoot. The footage is already 9:16, so no conversion is needed. This is the right call when you know the final destination is short-form — the framing is honest, the motion feels native, and you skip the cropping step.

Option B: Shoot horizontal and crop in post

Shoot in landscape if you need flexibility — interviews, documentary footage, travel clips where the horizontal framing is part of the look. Crop to 9:16 in your editor by reframing the shot.

ReelClip exports trimmed clips at the original aspect ratio — it does not auto-crop or zoom. If you shoot horizontal and want vertical output, crop the framing yourself in your finishing editor, or use ReelClip's Slice mode which gives you full manual control over the frame.

The on-device workflow

Step 1: Import the footage

Open ReelClip and import from Photos or Files. The file is copied into the app's private sandbox — nothing is uploaded.

Step 2: Pick a cut mode

For vertical content, the right cut mode depends on what you are editing:

See how to cut a long video for TikTok for the detailed Cut mode workflow.

Step 3: Review every clip

Tap each planned clip, watch it from start to finish, and decide: keep, trim, or reject. ReelClip never auto-exports — you stay in control. Trim the start (the first second is what viewers decide on) and the end of each clip.

Step 4: Add captions

Around 80% of vertical video is watched on mute. Burned-in captions are not optional. ReelClip generates captions from the on-device transcript with one of four styles:

You can also export the SRT or VTT file separately and bring it into CapCut, VN, or any other editor that accepts caption files.

Step 5: Apply a LUT if you want a stylized grade

If you are grading DJI, Sony, or other log footage, apply the camera transform first, then stack a creative LUT on top. See the best free LUT packs in 2026 for the curated list of free packs and how to apply a .cube LUT on iPhone for the apply workflow.

Step 6: Export to Photos

Tap Save clips. ReelClip exports each approved clip to your Photos library at the original aspect ratio. The original file stays untouched.

Step 7: Post to all three platforms

One clip, three platforms. Upload the same file to Instagram Reels, TikTok, and YouTube Shorts — they all accept the same 9:16 MP4. Cross-posting is the cheapest growth move in short-form video.

Common vertical-video mistakes

What to do next

For the broader short-form workflow including the Cut mode settings, see how to cut a long video for TikTok. For the podcast angle, see how to extract highlights from a podcast. For a comparison with CapCut and other iOS editors, see the best CapCut alternative without a watermark.