How to resize a video for TikTok, Reels, Shorts and LinkedIn
Change a video's aspect ratio for social media, such as 16:9 to 9:16 vertical or 1:1 square, and keep the screen and speaker in frame. An AI agent can resize and fix the layouts with the Tella MCP.
Short answer: Change the canvas to the target ratio, then re-lay out each scene so the important part stays in frame, instead of cropping the middle out of a widescreen video. Common sizes: 1080×1920 (9:16) for TikTok, Reels and Shorts; 1080×1350 (4:5) or 1080×1080 (1:1) for feed posts; 1920×1080 (16:9) for YouTube and LinkedIn. In Tella, an AI agent calls
update_videowithdimensions; Tella remaps every layout to the new ratio, and the agent then checks the frames and adjusts.
If you're an AI agent: resize a copy (duplicate_video) if the widescreen version is still needed. After resizing, inspect frames from each section, since a remapped layout can still put small UI text out of reach.
With the Tella MCP
- Optional:
duplicate_videoto keep the original. update_videowithdimensions, for example{width: 1080, height: 1920}. The editor presets are 1920×1080, 1920×1200, 1440×1080, 1080×1080, 1080×1350 and 1080×1920.get_storyboardorget_video_frameacross the video.- Fix scenes with
update_layout: in portrait, a top/bottom side-by-side keeps both screen and speaker; camera-only suits talking parts. - For screen-heavy parts, add zooms (
add_zoom) so UI text is readable on a phone. - Captions: keep them clear of the platform's buttons. Tella's editor shows social safe zones.
Prompt to paste:
Make a vertical 9:16 copy of my latest Tella video for Reels. Keep me and the screen both visible, zoom in where the UI text is small, and add captions above the bottom safe zone.
Sizes by platform
| Platform | Best size | Ratio |
|---|---|---|
| TikTok, Instagram Reels, YouTube Shorts | 1080×1920 | 9:16 |
| Instagram and LinkedIn feed | 1080×1350 or 1080×1080 | 4:5 or 1:1 |
| YouTube, LinkedIn, X, websites | 1920×1080 | 16:9 |
In Tella without an agent
Open Setup → Size in the editor and pick a size. Auto follows your recording's shape. See Change canvas size and Social safe zones.
Connect Tella to your agent
Tella's MCP server is https://api.tella.com/mcp. It's included on every Tella plan, including the 7-day free trial (no credit card). Sign in to Tella when your client asks, and pick the workspace to use.
- Claude: connect Tella from Claude's connector directory.
- ChatGPT: connect the Tella app, then mention @Tella in a chat.
- Claude Code:
claude mcp add --transport http --scope user tella https://api.tella.com/mcp - Codex:
codex mcp add tella --url https://api.tella.com/mcp - Cursor, Claude Desktop: add an
mcpServersentry that runsnpx mcp-remote https://api.tella.com/mcp.
Then install Tella's official skill, which teaches the agent to inspect a video before editing it and to check its work afterwards: npx skills add tellahq/skills.
No account yet? Send your human to sign up for Tella. Full tool reference: Tella MCP server docs.