Silence SpeedUp

Silence SpeedUp shortens videos by finding the silent stretches and either speeding them up or cutting them out. FFmpeg does the encoding; this app decides what to ask it for.

Made for lectures, interviews, podcasts and tutorials — anything where the speaker pauses a lot or talks slowly.

Download

• Free, for Windows and Linux: from the latest release. The Windows installer is not signed, so Windows SmartScreen may warn about an unknown publisher the first time; choose More info → Run anyway.
• From the Microsoft Store: the same app, signed and kept up to date by the Store. It is paid, and buying it is also a way to support the project.
• From source: see Building from source.

Coming from 2.x? See docs/porting-notes.md. A presentation of the app, in English and Italian, is on the author's site.

Getting started

1. Add your videos — Add, a folder, or drag them onto the window.
2. Adjust the settings if you want to; the defaults suit most recordings.
3. Press the play button on a row to hear a short preview sample first, then press Start.

Results land next to the original videos by default; another folder can be chosen in the Export group of the encoding settings.

Full walkthrough of every setting: docs/usage.md.

Features

• ⏩ Speed up or remove the silences, and optionally mute them
• 🗣️ Speed up the speech too, if you want the whole video faster
• 🎙️ Tunable detection — noise threshold, minimum pause length, and a margin so words are not clipped
• 📏 A measured threshold — the app reads the recording's background noise and voice level and suggests the value between them
• ▶️ Preview — encode a short sample and hear the result before processing the whole file
• 🔍 Quick analysis — every pause on a zoomable timeline, with the estimated length of the result
• 🎧 Multi-track audio — keep every track while detecting the pauses from the first one, as an OBS recording with voice and system audio needs
• 📋 Batch processing with a queue, a live log and a run you can stop
• 🎛️ Encoder controls — CRF, frame rate, x264 preset and tune, audio rate, output container
• 🪟 Compact progress mode — a slim always-on-top strip for long batches
• 🌗 Light, dark or system theme, in English, Italian, German, Spanish, French, Portuguese and Japanese
• 📦 FFmpeg included — nothing to install

Requirements

Nothing to install alongside it: FFmpeg ships with the app.

• Windows: 10 or newer, 64-bit.
• Linux: x86_64, with GTK 3 and xdg-desktop-portal, which every full desktop (GNOME, KDE, Xfce, ...) already has. Built and tested end to end on Ubuntu 22.04. On Ubuntu 24.04, Debian 12 and Fedora 41 only its libraries have been checked: they all load, but the app has not been run there yet.

Building from source

Every platform needs Flutter 3.47 or newer, on the stable channel.

• Windows: Visual Studio 2022 with the Desktop development with C++ workload. The steps, and packaging the installer, are in docs/development.md.
• Linux: clang, CMake, Ninja, GTK 3 headers, patchelf, and the codec libraries FFmpeg was linked against. The steps are in docs/linux.md, which also explains how to build the Linux version from Windows with Docker.
• macOS: Xcode and CocoaPods; then flutter run -d macos. The macOS build is not currently tested.

git clone https://github.com/padvincenzo/silence-speedup
cd silence-speedup
flutter pub get
flutter run -d windows    # or: flutter run -d linux / -d macos

Documentation

Document	What is in it
docs/usage.md	Every setting, what it does, and how to fix a bad result
docs/porting-notes.md	Coming from 2.x, why Flutter, and what changed from the Electron app
docs/architecture.md	How the code is organised and why
docs/ffmpeg-details.md	The exact FFmpeg commands, flag by flag
docs/development.md	Building, testing, releasing, extending
docs/linux.md	Building and trying the Linux version, from Windows too
docs/microsoft-store.md	For the maintainer: packaging and publishing the Store version
ROADMAP.md	What is not built yet
CLAUDE.md	Working rules for AI assistants in this repo

Contributing

Welcome, in any of these forms:

• Reporting bugs
• Translating the app (copy lib/l10n/arb/app_en.arb, change @@locale, and run flutter gen-l10n; the new language appears in the menu on its own)
• Suggesting or implementing features from ROADMAP.md
• Buying me a coffee

Before a pull request: flutter analyze clean, flutter test green, and any change to the FFmpeg calls covered by a test in test/fragment_planner_test.dart or test/preview_and_audio_test.dart.

Credits

• FFmpeg, bundled under the GPLv3, via ffmpeg_kit_flutter_new
• Flutter for the interface
• Icons from creazilla.com under CC BY 4.0

AI assistance

Parts of the code were written with an AI assistant, then reviewed and maintained by the author, who is responsible for it.

The app itself contains no AI, and sends nothing anywhere: the silences are found by measuring the audio level with FFmpeg's silencedetect, which is a threshold and a stopwatch, not a model.

Privacy

Videos are processed on your computer and never leave it. There are no accounts, no analytics and no tracking. The only connection the app makes is the update check of the GitHub version, which reads the public list of releases; the Store version does not make it. The details are in the privacy policy.

Licence

GPLv3 or later. Copyright (C) 2026 Vincenzo Padula.

This program comes with absolutely no warranty. It is free software, and you are welcome to redistribute it under certain conditions; see LICENSE.