| Software | Platform | How to Use | |----------|----------|------------| | (free, open‑source) | Windows/macOS/Linux | 1. Install → 2. Open HandBrake → 3. Drag‑and‑drop the .3gp → 4. Choose a preset (e.g., “Fast 1080p30”) → 5. Click Start Encode . | | FFmpeg (command‑line) | All platforms | ffmpeg -i input.3gp -c:v libx264 -crf 23 -c:a aac -b:a 128k output.mp4 |