ConvertiSlowed
Information
About
A slowed + reverb converter with no account, and none of your files are kept.
Updated on August 22, 2026
What ConvertiSlowed does
ConvertiSlowed turns a track into a slowed + reverb, nightcore or sped up version. Import a file or paste a link, set speed, reverb and bass, listen to the result live, then export to MP3, WAV or FLAC.
Everything happens in your browser, with nothing to install and no sign-up. Local file mode is free, unlimited and account-free — and will stay that way. YouTube mode, whose extraction costs money and needs constant upkeep, is paid: €6.99 for seven days or €19.99 for a year, a one-off payment with no subscription and no renewal.
Why this tool exists
Slowing a track down and adding reverb has become a language of its own, born on SoundCloud and spread by TikTok. The available tools, though, stayed awkward: heavy software, sites drowned in ads, exports locked behind a subscription.
ConvertiSlowed came out of that frustration. The idea is simple: give precise control over the three settings that matter, with instant playback, and ask for nothing in return.
The principles behind the service
Your files do not stay. An imported file is processed then deleted automatically, within thirty minutes at most. There is no account, no history and no shared library.
No crippled quality. All six presets, the three fine settings and the three export formats are available to everyone, in both modes, with nothing held back to push you towards a paid plan. What you pay for is access to YouTube extraction, not the quality of the result.
Restraint rather than collection. No data is ever sold, and audience measurement only runs if you agree to it.
Respect for other people’s work. The tool is technical and neutral: it offers no catalogue. It is up to you to only process content you are entitled to process.
Who is behind it
ConvertiSlowed is designed and maintained by Mickaël Barthémy, an independent developer based in Paris. The project is run alone: the code, the design, the writing and the support all come from the same person.
That has one honest consequence: replies can take a little time. In exchange, every message is read, and many improvements come straight from them.
How it works, technically
Audio processing combines an in-browser synthesis engine for real-time playback with server-side processing for the final export, so the downloaded file matches exactly what you heard. Extraction from a link relies on open source tools, kept up to date.
The site is hosted in Switzerland, at Infomaniak, on infrastructure powered by renewable energy.