About AudioTools.dev
AudioTools.dev is a set of free audio tools that run entirely in your web browser. Your files are processed on your device and are never uploaded. There are no accounts, no usage limits and no ads, and the code is open source under the MIT license.
What you can do here
- Audio Converter — WAV, FLAC, OGG, AAC, M4A, WebM to MP3 or WAV
- Audio Trimmer — cut a part of a recording on a waveform
- Audio Joiner — merge files, with optional crossfade
- Volume Booster — make quiet audio louder or normalize it
- Speed Changer — 0.25× to 4× without changing pitch
- Audio Compressor — smaller MP3 files at a bitrate you choose
- Text to Speech — read text aloud in 50+ languages
- Voice to Text — live dictation, or private transcription with Whisper on your device
Who makes it
AudioTools.dev is built and maintained by Roman Gordienko, a backend developer working with Go and Python. It is an independent open-source project, started in January 2026. The changelog lists everything that has shipped since.
How your files stay on your device
Every tool decodes, edits and encodes audio inside your browser with the Web Audio API and WebAssembly. Nothing is sent to a server, because there is no server: the site is a set of static pages on GitHub Pages.
You can check this yourself:
- Open your browser's developer tools (F12) and go to the Network tab.
- Process a file with any tool.
- You will see no request that carries your audio.
What the site does load from the network, so the list is complete:
- the pages themselves, from GitHub Pages;
- the Archivo typeface, from Google Fonts;
- the MP3 encoder (lamejs) from cdnjs, on tools that write MP3;
- the Whisper speech model from Hugging Face, once, when you use Private mode in Voice to Text;
- Google Analytics and Yandex Metrika for anonymous page-view statistics (see the privacy policy).
One exception is worth knowing: live dictation in Voice to Text uses your browser's speech engine, and Chrome and Safari may send that audio to Google or Apple. Private mode does not.
How it compares to upload-based converters
| AudioTools.dev | Typical upload-based site | |
|---|---|---|
| Your files | Stay on your device | Uploaded to a server |
| Account | Not needed | Often required for full features |
| Limits | None, apart from your device's memory | Often a daily limit or file-size cap |
| Ads | None | Usually |
| Source code | Open, MIT license | Closed |
How it is built
- Decoding and processing: Web Audio API (
OfflineAudioContext) - MP3 encoding: lamejs
- Speed change without pitch shift: WSOLA time-stretching
- Private transcription: Whisper (tiny/base) via Transformers.js in a Web Worker
Related open-source projects
- go-audio-converter — pure Go audio converter, no FFmpeg, single binary
- voice-to-text — bulk voice message transcription with Whisper
- music_recognition — bulk music identification and tagging
- audiobook-cleaner — AI noise removal for audiobooks
Contact and feedback
Found a bug or missing a tool? Open an issue on GitHub. If the tools save you time, you can support the project on Boosty.