Click, Select, Merge: A Simple Windows GUI to Combine Videos Using Python

This app lets a non-technical user:

select multiple videos
choose where to save the final video
click Merge Videos
wait
done

No command line. No confusion.

What this GUI will do

✔ Select multiple video files
✔ Show selected files in a list
✔ Merge videos using FFmpeg (fast + safe)
✔ Show success or error messages
✔ One-click experience

Requirements (one-time setup)

1. Python installed

Make sure this works:

python --version

2. FFmpeg installed

FFmpeg must exist here:

C:\ffmpeg\bin\ffmpeg.exe

Test:

"C:\ffmpeg\bin\ffmpeg.exe" -version

Project structure

video-merger-gui/
│
├── app.py
└── (your videos anywhere on your PC)

That’s it.

The GUI App (copy–paste)

import tkinter as tk
from tkinter import filedialog, messagebox
import subprocess
import os

FFMPEG_PATH = r"C:\ffmpeg\bin\ffmpeg.exe"


class VideoMergerApp:
    def __init__(self, root):
        self.root = root
        self.root.title("Video Merger")
        self.root.geometry("600x400")
        self.video_files = []

        # Title
        tk.Label(
            root,
            text="Video Merger",
            font=("Segoe UI", 18, "bold")
        ).pack(pady=10)

        # Buttons
        tk.Button(
            root,
            text="Select Videos",
            command=self.select_videos,
            width=20
        ).pack(pady=5)

        tk.Button(
            root,
            text="Merge Videos",
            command=self.merge_videos,
            width=20
        ).pack(pady=5)

        # Listbox
        self.listbox = tk.Listbox(root, width=80, height=10)
        self.listbox.pack(pady=10)

        # Status
        self.status = tk.Label(root, text="", fg="green")
        self.status.pack(pady=5)

    def select_videos(self):
        files = filedialog.askopenfilenames(
            title="Select Video Files",
            filetypes=[
                ("Video Files", "*.mp4 *.mov *.avi *.mkv")
            ]
        )

        if files:
            self.video_files = list(files)
            self.listbox.delete(0, tk.END)
            for file in self.video_files:
                self.listbox.insert(tk.END, file)

    def merge_videos(self):
        if not self.video_files:
            messagebox.showwarning("No Videos", "Please select videos first.")
            return

        output_file = filedialog.asksaveasfilename(
            defaultextension=".mp4",
            filetypes=[("MP4 Video", "*.mp4")],
            title="Save Combined Video As"
        )

        if not output_file:
            return

        list_file = "files.txt"

        try:
            with open(list_file, "w", encoding="utf-8") as f:
                for video in self.video_files:
                    f.write(f"file '{os.path.abspath(video)}'\n")

            self.status.config(text="Merging videos... Please wait.", fg="blue")
            self.root.update()

            subprocess.run(
                [
                    FFMPEG_PATH,
                    "-f", "concat",
                    "-safe", "0",
                    "-i", list_file,
                    "-c", "copy",
                    output_file
                ],
                check=True
            )

            self.status.config(text="Done! Video merged successfully.", fg="green")
            messagebox.showinfo("Success", "Videos merged successfully!")

        except Exception as e:
            messagebox.showerror("Error", str(e))
            self.status.config(text="", fg="red")

        finally:
            if os.path.exists(list_file):
                os.remove(list_file)


if __name__ == "__main__":
    root = tk.Tk()
    app = VideoMergerApp(root)
    root.mainloop()

How a non-technical user uses this

Double-click the app (or run python app.py)
Click Select Videos
Choose videos (order matters)
Click Merge Videos
Choose where to save
Done

No terminal. No errors. No drama.

Important note (you should tell users this)

This fast merge requires videos to have:

same resolution
same frame rate
same codec

If videos come from the same camera or screen recorder, they’re fine.

Rashed Hossain