Hydrogen review: drum patterns on your computer

Hydrogen is a free open-source drum machine for people who want to program rhythms on a desktop computer.⁵⁴ It is a pattern-based sequencer and a drum synth: you place hits on a grid, arrange those patterns into a song, and play them with sampled sounds.³⁴ A song is a file you save in a folder you choose, and downloading an extra drumkit is a separate step.³

Last checked October 28, 2026.

At a glance

What it is: A desktop drum sequencer and drum synth that builds songs from patterns.⁴

Works on: Linux, macOS 10.14 and newer, and 64-bit Windows. Official 32-bit Windows builds stop at version 1.2.3.²

Price: Free software. Flathub lists the Linux package as free, and the project publishes installers on its downloads page.⁵⁷²

Licence: GNU GPL version 2 or later. The project calls this GPLv2+.⁵⁴

Best for: Building drum patterns and songs on a computer you control.

Official site: hydrogen-music.org

What Hydrogen does (and how it protects your privacy)

Hydrogen emulates a drum machine you can use on its own, or with a MIDI keyboard or another sequencer.³ MIDI is a note language that electronic instruments use to talk to software. A pattern is one short grid of hits. The song editor lines those grids up, and several can play at once, so a groove and a fill can stay separate.³ The sounds live in a drumkit: instruments that can each use more than one sample, which is a short recording such as a single snare hit.³

You can click notes in, or record them from the on-screen keyboard or a MIDI device such as an electronic drum kit.³ When the part is ready, export an audio file or a MIDI file.³

Save As writes the song as a .h2song file in a folder you choose.³ Those files do not contain the samples.³ Samples stay with the drumkit, and kits you add are stored in Hydrogen’s data folder on that computer.³ To trim the exported recording later, use Audacity on the same computer.

Hydrogen’s key features

Pattern and song editing: Arrange patterns so several can play at the same time.³
Layered drumkits: One instrument can hold several layered samples.³
Velocity: A velocity control adds randomness to how hard each hit is.³
Playing in: Record with the mouse, the on-screen keyboard, or a MIDI device such as an e-drum.³
Piano roll: Switch the pattern editor to a piano keyboard for pitched notes.³
Studio connections: Other programs can drive Hydrogen over MIDI or OSC.⁴ OSC is a message system for sending commands between programs.
Drumkit import: Load a kit file from your computer, or download one. The window shows that kit’s licence.³
Export: Write one stereo mix, separate instrument tracks, or both.³

Hydrogen pros and cons

Pros

It is free software under the GPL, and Flathub lists the Linux package as free.⁵⁷
You choose the folder for each song file.³
Several patterns can play together, with layered samples for each drum.³
A MIDI keyboard or electronic drum kit can record the same patterns.³
Version 1.2.7 came out on 2 October 2026, so the project is still publishing updates.¹

Cons

The downloads page lists Linux, Windows and macOS. It does not list an iPhone or Android app.²
The current Windows installer is 64-bit. Official 32-bit Windows builds stop at version 1.2.3.²
A song file does not include the samples. Another computer also needs the drumkit, or those instruments stay silent.⁶³
The drumkit import window opens on an Internet tab that points at the project’s online kit list.³
The only effect-plugin format is LADSPA, aimed at Linux. The manual says a badly designed plugin can phone home.³

Is Hydrogen safe and private?

Hydrogen is developed by the Hydrogen development team. The copyright line in the 1.2.7 source runs from 2008 to 2026, and the code is on GitHub under GPLv2+.⁵⁴ The project homepage dates version 1.2.7 to 2 October 2026.¹ The release notes call it a patch for minor bugs, updated translations, and forward compatibility with the upcoming 2.0.¹⁸ Day to day, the manual describes files on your computer: a .h2song in a folder you choose, and your own drumkits in Hydrogen’s data directory.³

Import opens on an Internet tab, with the kit list on hydrogen-music.org filled in, and you choose what to download.³ A .h2drumkit file already on the computer can be imported instead.³ Song, pattern and playlist files do not contain the samples.³ Exporting a song or a kit does reuse them, and the manual says you must follow each sample’s licence. If the licence is missing, do not treat the kit as Creative Commons or another open licence.³ The project says it is not responsible for drumkits users offer for download.³

LADSPA is the only plugin format, and the manual says it is meant for Linux. It warns that a badly designed plugin can phone home, meaning the plugin contacts a server by itself.³ On Linux, Flathub’s version 1.2.7 is a community-provided package that the Hydrogen developers do not verify or support.⁷ Prefer the installers on the project’s downloads page.²

How to get started with Hydrogen

Download version 1.2.7 from the official downloads page. Use the Linux AppImage, the 64-bit Windows installer, or the Mac build for OS X 10.14 and above.² The manual sends you to that same page.³
On macOS Big Sur or newer, follow the extra note. The manual says you may need more steps before the app will run, and points to the project wiki.³
Open a demo song from the Project menu. Demos ship with Hydrogen.³
Make one short pattern. Click hits into the grid, or record them with the on-screen keyboard or a MIDI device.³
Save on your computer. Save As stores a .h2song file in a folder you choose.³
Add a kit deliberately. Import a .h2drumkit file you already have, or use Online Import, read the licence shown, and then download.³
Export a recording to share the sound. Export Song can write one stereo mix, separate instrument tracks, or both.³ Keep the .h2song file so you can edit the pattern later.

Who should use Hydrogen (and who might prefer something else)

Hydrogen fits someone who wants a drum machine on a computer: practice beats, sketch a rhythm, or record an electronic kit into local pattern files. The current release is from October 2026, for Linux, macOS and Windows.¹²

For bass, melody and drums in one program, use LMMS. For a printed score, use MuseScore Studio. Hydrogen can export LilyPond, but only for the GMRockKit and songs without triplets.³ To mix records you already have, look at Mixxx.

Frequently asked questions

Is Hydrogen free?

It is free software under the GNU GPL, version 2 or any later version.⁵ Installers are on the downloads page, and Flathub lists the Linux package as free.²⁷

Does Hydrogen work on iPhone?

The downloads page does not list an iPhone or Android app. It offers a Linux AppImage, a 64-bit Windows installer, and a Mac build for OS X 10.14 and above.² The manual describes Linux, Mac OS X and Windows.³

Does Hydrogen upload my drum patterns?

Save As writes a .h2song file to a folder you choose, and that file does not contain the samples.³ A kit download is separate: the import window opens on an Internet tab pointed at the Hydrogen website.³

Can I sell music I make with Hydrogen?

The FAQ says you can use Hydrogen and its main sound libraries in your own work and sell that music.⁶ You must read the licence of any other library before a song that uses it is sold.⁶ The manual says an export reuses the samples, so each licence still applies, and a missing licence is not a reason to treat the kit as free to share.³