Helm review
A capable free synth for electronic music, available standalone or across major plugin formats.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Helm is a free, open-source polyphonic software synthesizer for creating electronic music on GNU/Linux, macOS, and Windows. It works as either a standalone application or a plugin, making it suitable for producers who want one instrument that can run independently or inside compatible music software. Its core sound engine combines dual oscillators, cross modulation, unison voices, a sub oscillator with waveshaping, filters, modulation sources, sequencing, arpeggiation, and built-in effects.
The pricing model is straightforward: Helm is pay what you want, including paying nothing. There are no fixed paid product tiers to compare. The published feature set includes a step sequencer, arpeggiator, formant filter, stutter, delay, distortion, reverb, patch browsing, and patch export. Modulation includes live visual feedback and polyphonic aftertouch as a modulation source, giving the instrument useful depth for sound design without placing it in a paid tier structure.
Helm also fits a broad plugin ecosystem. It supports LV2, VST, VST3, AU, and AAX, alongside its standalone application, so its deployment options cover GNU/Linux, macOS, and Windows. The official GitHub repository was archived on February 8, 2025, while the official website and downloads page remain live. Helm is a sensible pick for musicians seeking free general-purpose synthesis with open-source licensing and wide plugin compatibility. Users who need a broader feature set or a more actively developed repository should consider another synthesizer instead.
Helm pros and cons
- Where it wins
- Free and open source with standalone operation
- Dual oscillators, cross modulation, and unison voices
- Broad plugin support across LV2, VST, VST3, AU, and AAX
- Where it doesn't
- No fixed paid plans or product pricing structure
- The official GitHub repository was archived on February 8, 2025
- Its feature set may not suit users seeking broader synthesis tools
Helm fact sheet, pricing and score →
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