A free audio editor built for podcasters and voiceover
Altered Audio Editor is an open-source multitrack editor from The GCRN. It follows the editing workflow experienced editors already know, with its own original design, then adds tools built for podcast production.
Pre-release software. Keep backups of your recordings.
- Price
- Free
- License
- GPL-3.0 or later
- Account
- None, ever
- Builds
- Windows, plus experimental Linux and macOS
Why we built it
The GCRN has been making podcasts since 2009, and Steve Phillips has been editing them since 2006. General-purpose editors can do everything, which means the podcast chores happen by hand every episode: level the hosts, quiet the breaths, fit a 30 second ad, add chapters, export, write the notes.
Altered Audio Editor keeps the workflow you already know and builds those chores in. It stays free because we want it to stay free: no subscription, no account, no tracking. The source is open, so nobody has to take our word for that.
From raw tracks to a finished episode
The tools are organized the way an episode actually gets made.
Record or bring in your tracks
Record each speaker to their own file while the session plays, or open what your call recorder exported. It reads WAV, FLAC, MP3, AAC/M4A, ALAC, Ogg Vorbis, Ogg FLAC and Opus.
- Per-track inputs, every channel of an interface, punch-in with pre-roll and ASIO on Windows
- System audio capture on Windows, to record a call next to your mics
- Insert Files as Tracks, straight from a downloaded zip
- Session templates and Libraries for intros, outros, promos and ads
Balance and clean the voices
Speaker Balance levels every voice to the quietest in one click. Then build a Voice Chain of up to 16 live effects on any clip or track: Parametric EQ, De-Esser, Speech Leveler, Dynamics, Limiter, Breath Gate, Noise Reducer, Hiss and Room Reducers, Click and Clip Repair, Pitch Shift and more. Any setting can change over time, drawn as points on the clip like a volume envelope.
- Presets like Podcast Voice and Voice Over, plus your own
- Host profiles: Close Mic, Standard Mic and Remote Guest
- Spectrum view: box, lasso or brush a whistle, buzz or chair squeak and remove only that
- Spot Repair fills a painted click or cough from the audio around it
- QuickPass finds silences, clicks, clipping and short noises
Edit the episode
Multitrack editing with the tools you would expect, plus a standalone waveform editor and a few tools made for production work.
- Move, razor, slip and time-selection tools with ripple delete
- Fades, crossfades, and volume and pan envelopes
- Waveform editor: open any file, preview a Voice Chain live, then apply it
- Time Stretch fits a clip to an exact 15, 30 or 60 second slot
- Music Fit offers up to three plans to make a music bed the right length
- Phase Align lines up two recordings of the same voice to the sample
Check the loudness
Loudness Match sets any clip or track to a podcast, platform or broadcast target. A loudness scan shows LUFS and true peak before you export. After each export, the app reopens the file and confirms it decodes, has the right length and sample rate, is not silent and holds its chapters.
Publish
Chapter markers are written into exported WAV, FLAC, MP3 and M4A files and read back when you open one. They also export as a timestamp list for video descriptions, a CSV or podcast chapters JSON.
- Publish Package: your MP3, show notes, chapters, soundbites and an episode.json with RSS.com API fields. Nothing is uploaded.
- Batch Convert a whole folder, optionally running a Voice Chain preset on each file
- Mixdown and stems as WAV, FLAC, MP3 or AAC/M4A at any sample rate
See it working
Everything it does today
The full feature list for the current release, straight from the project.
- Multitrack editing
- Move, razor, slip and time-selection tools. Trim, split, merge, loop and copy clips, with fades, crossfades, clip volume and pan envelopes, markers and ripple delete.
- Waveform editor
- Open any file on its own to cut, silence, amplify and fade it. Try a Voice Chain as a live preview, apply it to the selection or the whole file (undoable), then save in place as WAV, FLAC, MP3 or M4A, or as a new file.
- Opens what call recorders export
- WAV (including 8-bit and ADPCM), FLAC, MP3, AAC/M4A, ALAC, Ogg Vorbis, Ogg FLAC and Opus. Insert Files as Tracks puts each speaker on their own track, straight from a downloaded zip.
- Spectrum and pitch views
- See frequencies over time. Select an unwanted sound, like a whistle, a buzz or a chair squeak, with a box, lasso or brush and reduce, remove or repair just that. Spot Repair fills a painted click or cough from the audio around it.
- Recording
- Arm tracks, pick each one’s input (every channel of an interface works) and record to their own files while the session plays. Punch in over a time selection with pre-roll, and set a latency offset so takes line up. ASIO on Windows release builds, the system driver everywhere. On Windows, a System audio input records what the computer plays, such as a call.
- Voice Chain effects
- Up to 16 per clip or track, heard live and included in every export. Parametric EQ, Hum Cut, Dynamics, Limiter, Breath Gate, De-Esser, Speech Leveler, Gain, Noise Reducer, Noise Print Reducer, Sound Eraser, Hiss Reducer, Room Reducer, Click Repair, Clip Repair, DC Offset Fix, Band EQ (10, 20 or 30 bands), Curve EQ, Notch Filter, Precision Filter, Center Remover, Phase Rotate and Pitch Shift.
- Voice Chain control
- Each effect opens in its own movable window. Any setting can move over time, drawn as points on the clip. Sliders change the sound as you drag without stopping playback, meters show the chain’s level in and out, and EQs and filters draw their response. Start from presets like Podcast Voice or Voice Over and save your own.
- Speaker Balance and host profiles
- Level every voice track to the quietest in one click before processing, and start each host’s track from a Close Mic, Standard Mic or Remote Guest profile.
- Playback and metering
- Live mixing with per-track volume, pan, mute, solo and polarity. Loop Playback and Skip Selection. Stereo meters on every track with peak hold and clip lights.
- Libraries and session templates
- Keep your show’s intros, outros, promos and ads in one place and drag them onto tracks. Start every episode from your show’s own track layout.
- QuickPass
- Scan for silences, short noises, clicks, clipping or the parts with sound. Remove silences (keeping a short natural pause), turn them down, split or mark them. Clicks and clipped peaks are repaired into a copy of the clip’s audio, so the original is never touched. Includes presets and saves your own.
- Loudness Match
- Set each clip or track to a podcast, platform or broadcast target in one step. Broadcast targets follow your region (US by default).
- Time Stretch
- Fit a clip to an exact length, like a 15, 30 or 60 second ad slot or a time selection, keeping the pitch. Or change speed and pitch together, like tape.
- Music Fit
- Make a music bed an exact length without changing its speed. It cuts out or repeats whole sections where the music lines up, keeps the intro and ending, and leaves the joins as editable crossfades. It offers up to three plans that join in different places and tells you where each one joins.
- Phase Align
- Line up two recordings of the same voice, like a host mic and a room mic, or a camera and a recorder, to the sample, flipping polarity when needed.
- Chapters
- Export chapter markers as a timestamp list for video descriptions, a CSV spreadsheet or podcast chapters JSON, with an optional link each and tips on titles. They are written into exported WAV, FLAC, MP3 and M4A files and read back when you open one.
- Mixdown and stems
- Export the session, a selection or each track as WAV (4-bit ADPCM, 8, 16, 24 or 32-bit float), FLAC, MP3 (constant or variable bit rate) or AAC/M4A (on Windows), at any sample rate, with a loudness check for LUFS and true peak.
- Export check and Publish Package
- After each export the app reopens the file and confirms it opens, decodes, has the right length and sample rate, is not silent and holds its chapters. File, Publish Package exports the MP3 and writes a folder with episode.json (RSS.com API fields), show notes, chapters and soundbites. Nothing is uploaded.
- Batch Convert
- Turn a folder of files into WAV, FLAC, MP3 or AAC in one go. Optionally run a Voice Chain preset on each, then normalize the peak and fade the ends. Set naming, destination folder, sample rate, channels and dither, watch per-file progress, and copy tags across or set them for every file.
- Sessions from other editors
- Imports .sesx multitrack sessions (tracks, clips and positions). File, Export, Multitrack Session (.sesx) writes a copy for editors that read that format, with tracks, clips, levels and fades. Effects stay behind.
- Music Mode (off by default)
- View, Music Mode adds the music tools without changing the podcast layouts: MIDI tracks with a piano roll and VST3 instruments, an Amp Model effect that loads Neural Amp Modeler captures, a metronome, a tempo strip and Bars and Beats time. The Music workspace turns it on for you.
- Also in the current release
- Buses, sends and sidechain. VST3 plug-ins in Voice Chains, each in its own process. A Phase Wheel and a 3D Space panel, both under the Window menu. Convolution Reverb, Vox Strip, Reverse, Invert Polarity, fade bending and searchable effect lists, adapted from the Audiform project (see the repository’s ATTRIBUTION file).
- Settings and updates
- Edit, Settings holds zoom, fades, colors, output device, autosave, solo, meter colors, recording offset, time format, loudness defaults, session backups and a record count-in. Help, Check for Updates finds new versions and can install them (installer copies only; the portable zip opens the download page).
- Open, documented file formats
- Every file the app writes is versioned JSON: sessions (.altaudio), libraries, session templates (.altemplate), workspaces (.alworkspace), host profiles (.alhost) and keyboard shortcuts (.alkeys). Schemas live in the repository’s schemas folder.
Download
Windows 10 and 11 (64-bit). Open the latest release and pick one file under Assets.
Altered-Audio-Editor-<version>-setup.exe- The installer. Adds a Start menu entry and an uninstaller, and works per user or for all users.
Altered-Audio-Editor-<version>-portable.zip- No install. Unzip it anywhere, including a USB drive, and run the app.
SHA256SUMS.txt- A checksum for each file, so you can confirm your download is intact.
If Windows warns you
The app is not code signed yet, so Windows SmartScreen may say it does not recognize it. Choose More info, then Run anyway. A few antivirus scanners may flag new, unsigned installers with a low-confidence guess, which fades as the file builds a reputation.
To check your copy, compare its SHA-256 with SHA256SUMS.txt. In PowerShell:
Get-FileHash .\Altered-Audio-Editor-<version>-setup.exeBuilds are made by GitHub Actions from the tagged source, so what you download matches what is in the repository.
Linux and macOS
Releases also carry a Linux AppImage and .deb, and a macOS .dmg for Apple silicon Macs. They are built from the same source but not tested by us yet, so reports are welcome. The macOS app is not notarized: the first time, right-click it and choose Open. AAC export works on Windows only for now.
Build from source
Setup steps for Rust, Node and the Microsoft build tools are in the repository’s Windows setup guide.
Private by design
No account
There is no login. Ever.
No tracking
No telemetry, no analytics.
No surprise network calls
Update checks run only when you click Help, Check for Updates, or if you turn on the weekly check. Nothing installs without your click.
Your audio stays put
Your recordings never leave your computer.
Where it stands
Altered Audio Editor is in active development, currently in its effects phase, and early versions are pre-releases. Version 0.6.0 added markers in every format, a check on each exported file and a Publish Package for your podcast host. Editing, playback, recording, the Voice Chain effects, conversion and mixdown work today. Expect rough edges and keep backups.
- Not there yet
- Transcripts, code signing, macOS notarization, and tested Linux and macOS builds.
- Full roadmap
- The phase plan and decisions log live in the project repository.
Questions
Is Altered Audio Editor really free?
Yes. It is free, open source and licensed under GPL-3.0 or later. If it helps your show, you can support the project at paypal.me/scp21.
Do I need an account?
No. There is no account, no login and no tracking.
Does it use AI?
Not unless you turn it on. Everything described on this page runs on your own computer.
Which systems does it run on?
Windows 10 and 11 (64-bit) is the primary build. Linux and macOS (Apple silicon) builds exist but are experimental.
Can I open sessions from other editors?
It imports .sesx multitrack sessions, bringing in tracks, clips and positions. File, Export, Multitrack Session (.sesx) writes a copy for editors that read that format. Effects stay behind in both directions.
Is it only for podcasts?
Podcasts and voiceover come first. Music Mode is off by default, and turning it on adds MIDI tracks with a piano roll, VST3 instruments, an Amp Model effect for Neural Amp Modeler captures, a metronome, a tempo strip and bars-and-beats time.
What file formats can it open and export?
It opens WAV (including 8-bit and ADPCM), FLAC, MP3, AAC/M4A, ALAC, Ogg Vorbis, Ogg FLAC and Opus. It exports WAV, FLAC, MP3 and AAC/M4A (AAC on Windows), with chapter markers written into WAV, FLAC, MP3 and M4A files.
How do updates work?
Choose Help, Check for Updates. The app can install new versions for installer copies, and the portable zip opens the download page. A weekly check is optional and off unless you turn it on. Nothing installs without your click.
Can I fork it?
Yes, under the GPL. The name Altered Audio Editor and its logo are trademarks of The GeekCast Radio Network, LLC and are not covered by the GPL, so forks should use a different name. See the repository’s TRADEMARKS file.
How do I report a bug or contribute?
Open an issue or a pull request on GitHub. Security problems go through the private process described in the repository’s SECURITY file.
Help it grow
Use it and tell us what broke
Try it on a real episode (with a backup) and report what you find on GitHub Issues. Linux and macOS reports are especially useful.
Send a pull request
Bug fixes and features are welcome. Start with CONTRIBUTING.md.
Support the project
It is free to use. If it saves your show some time, you can chip in on PayPal.
Made by Steve Phillips
Steve is the founder of The GCRN, goes by Steve Megatron on the air, and wrote Altered Audio: Podcasting Demystified. The editor shares its name and its goal with the book: make this work less mysterious.
Copyright The GeekCast Radio Network, LLC. Licensed under the GNU General Public License v3.0 or later. Altered Audio Editor and its logo are trademarks of The GeekCast Radio Network, LLC. All icons and artwork are original. This project is independent and not affiliated with or endorsed by any other software company.