Why these tools are free

A sound engineer works alone, and that is the problem

You mix for eleven hours. You decide everything: the level, the balance, what stays and what goes. And by the end of it you are the last person on earth who can still hear the record, because you have listened to it four hundred times.

Most engineers solve this the same way — by finding someone else's ears. We pay someone. They listen, and a few days later a text comes back: this frequency is ringing, this passage saturates, you are two decibels louder than the records you named. Not a treatment. A second opinion. The fixing is still yours to do, and that is the point: doing it yourself is how you get better.

Alumire is that second opinion, in the browser, immediately, for nothing. It does not touch your music. It tells you where you are.

Where it comes from

The engineers behind this have been shaping records for other people since 2000, first independently, then from Leizart — a Paris studio, open since 2008, where artists come from all over the world to record, mix and master.

For the last ten years the group has run as a non-profit: a way of sharing methods between its members rather than each of us re-learning the same lesson alone. Along the way we built our own tools — small, unglamorous, precise — to sit beside the plugins we license and the open-source work we depend on. They were never products. They were what we reached for at two in the morning when something sounded wrong and nobody was awake to ask.

In 2026 we asked the obvious question: why is this only ours?

What we get out of it

Free, without ads or uploads — so it is reasonable to ask why.

We built these tools for our own work first. Sharing them puts them in front of workflows, files and edge cases we would never encounter alone. Your feedback helps us improve them — and those improvements come back into our own work too.

That exchange is the point. You get useful tools. We get better tools.

The more workflows a tool encounters, the more useful its weaknesses become.

It also explains the shape of the site. Your file is processed locally in your browser; it is not uploaded to Alumire's servers. That is the architecture rather than a promise, and you can check it by disconnecting once the page has loaded.

Push it further

Alumire is in beta, and we would rather say so than let you find out on your own file. Some tools still break, and some are missing the one thing that would make them usable. Unexpected results, unusual files and difficult edge cases are useful: they show us where a tool needs to improve.

Write to us. Three kinds of message help most:

• “This is broken.” What you clicked, what you expected, what happened instead. The most valuable message there is.
• “This is wrong.” A number you can prove is off, a verdict that misreads your genre, a formula we got backwards. We publish our formulas precisely so they can be checked.
• “I need something you do not have.” Describe the moment in your work where you are stuck. Several tools on this site exist because somebody described exactly that.

We read all of it, we act on what we can, and we come back to tell you what changed because of you.