About WAV to MP3
WAV to MP3 is a free browser tool that compresses uncompressed audio into MP3 without uploading it. The file is decoded, re-encoded and handed back inside your own browser tab — no account, no watermark, no queue, and no copy of your recording sitting on someone else's disk.
This page exists because “nothing is uploaded” is a claim, and a claim is worth more when you know who is making it.
Who makes this
I'm Stanislav Mashkin, an independent software developer. This converter is built and maintained by me alone — no team, no investors, no roadmap written by someone else. It's one of a small set of single-purpose browser tools I run on the same principle: if the work can happen on your machine, it should.
The tools are published under STANMASH LTD, a private company limited by shares, registered in England and Wales on 14 July 2026 under company number 17337841. The registered office is Stoney Works, 8 Stoney Lane, London SE19 3BD, United Kingdom. That record is public — the link opens it at Companies House directly, no login needed.
Why it runs on your device
The usual free converter takes your upload, encodes it on a server and emails you a link. That works, and it means a stranger now holds your audio. For a lot of what people convert — an interview under embargo, a therapy session recording, a demo nobody has heard yet, a client's voiceover — that's the wrong trade.
Here a WebAssembly encoder runs inside a Web Worker on your own machine. There is no server in the loop that could keep the file, which is an architectural fact rather than a policy promise. The honest test: load the page, disconnect from the network, then convert something. It still works.
You can read the full privacy policy if you want the formal version.
What it does, and its limits
WAV in, MP3 out, at 128, 192, 256 or 320 kbps — 192 is the default because it's the point where most people stop hearing the difference. The reverse direction lives at MP3 to WAV, for when an editor or a mastering chain wants uncompressed input.
On a desktop browser a batch takes up to 15 files, 200 MB per file and 500 MB in total. On mobile those drop to 50 MB per file and 120 MB per batch, because a phone tab has far less memory to work with. Everything is held locally, so the ceilings are practical rather than arbitrary.
One thing worth saying plainly: MP3 is a lossy format. Converting WAV to MP3 discards audio data permanently, and converting back to WAV restores the container but not what was thrown away. Keep the original WAV if it's a master.
How it's funded
It isn't. No paid tier, no ads, no affiliate links, no data resold. A static site costs very little to run and this tool does one job completely, so there's nothing left to sell you. If that changes I'll write it here rather than quietly adding a limit — and whatever is free today stays free.
There's also a Chrome extension if you'd rather convert without opening the site. Same engine, same price.
Other tools I build
Same idea, different file types. pdfannotation.app highlights and signs PDFs without uploading them, csvtopdf.app turns spreadsheet exports into clean printable tables, and websitefeedback.tools is a Chrome extension for leaving review comments directly on a live web page.
Getting in touch
A file that won't convert, audio that comes out wrong, a format you wish were supported — email stasmashkin.art@gmail.com or find me on X as @mrstanmash. It's me reading it. A short description plus the file that broke beats a long description every time.
Want to convert something now? The WAV to MP3 converter is on the home page — nothing to install, nothing to sign up for.