---
title: "How to add a slide transition with Claude (tested prompt and ffmpeg command)"
description: "Clip B pushes in from the right edge and shoves clip A off to the left. Install one skill and ask Claude Code, or run the ffmpeg command we tested yourself."
url: https://www.recharm.com/effects/slide-transition
---

# How to add a slide transition with Claude

Clip B pushes in from the right edge and shoves clip A off to the left.

Made by the command on this page, from our own test clips.

## Get this effect

1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download)

2. ### Install the skill (once)

   ```
   Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skills
   ```

3. ### Ask for the effect

   ```
   Join clipA.mp4 and clipB.mp4 with a slide transition
   Length of the transition in seconds: 0.6
   ```

## Several videos, several effects, one ask

Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them.

Put a sale badge on **@clip1.mp4**, give **@clip2.mp4** a VHS look, then join them with a slide transition.

## Settings you can change

Ask Claude to change any of these, or edit them at the top of the command.

| Setting | Default | What it does                         |
| ------- | ------- | ------------------------------------ |
| `D`     | `0.6`   | Length of the transition in seconds. |

## In other editors

From each editor’s own help pages, in our words. We haven’t run these ourselves.

Built in: **Slide transitions** · web

1. Upload the video, then split it or add two clips.
2. Open Transitions in the sidebar and choose from the Slide category.
3. Click add to place the transition.

Source: [Free Video Transitions](https://www.capcut.com/tools/free-video-transitions) (CapCut), checked October 22, 2026.

## Without the skill

Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the command itself.

```
Join clipA.mp4 and clipB.mp4 with a 0.6 second slide transition where B pushes in from the right and pushes A out to the left (ffmpeg xfade slideleft). Crossfade the audio over the same 0.6 seconds. Match B's size and frame rate to A. Use ffmpeg and save it as output.mp4.
```

## Run it without Claude

This is the exact command we tested. Save it as `slide-transition.sh` and run:

```
sh slide-transition.sh clipA.mp4 clipB.mp4 output.mp4
```

```
#!/bin/sh
# Slide transition: clip B pushes in from the right and shoves clip A off to the left, over 0.6s. The sound crossfades underneath.
# Usage: sh slide-transition.sh clipA.mp4 clipB.mp4 output.mp4  (both clips need an audio track)
set -e
A="$1"; B="$2"; OUT="$3"
D=0.6   # transition length in seconds

LEN=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$A")
OFFSET=$(echo "$LEN - $D" | bc)
SIZE=$(ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 "$A")
FPS=$(ffprobe -v error -select_streams v:0 -show_entries stream=r_frame_rate -of csv=p=0 "$A")
W=${SIZE%x*}; H=${SIZE#*x}
# xfade needs both clips at the same size and frame rate, so B is fitted to A first
ffmpeg -y -i "$A" -i "$B" -filter_complex "\
[0:v]fps=$FPS,format=yuv420p,setsar=1[a];\
[1:v]scale=$W:$H:force_original_aspect_ratio=increase,crop=$W:$H,fps=$FPS,format=yuv420p,setsar=1[b];\
[a][b]xfade=transition=slideleft:duration=$D:offset=$OFFSET[v];\
[0:a][1:a]acrossfade=d=$D[au]" \
  -map "[v]" -map "[au]" -c:v libx264 -crf 18 -pix_fmt yuv420p -c:a aac "$OUT"
```

## More transitions

- [Barn door transition **Barn door transition**](https://www.recharm.com/effects/barn-door)
- [Blinds transition **Blinds transition**](https://www.recharm.com/effects/blinds-transition)
- [Block dissolve **Block dissolve**](https://www.recharm.com/effects/block-dissolve)
- [Blur transition **Blur transition**](https://www.recharm.com/effects/blur-transition)
- [Bounce transition **Bounce transition**](https://www.recharm.com/effects/bounce-transition)

## Find 3x _winning ads_

Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. Find the shots that win, add the effect with Claude, and ship 3x more ad edits.

[Start 14-day free trial](https://www.recharm.com/get-started)