FREE Filter VST Plugins

These are the best free filter plugins for Windows and macOS. For more software categories, return to our free VST plugins page.

Filters have the simple purpose of removing a certain area of the frequency spectrum. However, the filter can be a versatile creative effect if you pair it with distortion and clever modulation.

I listed my favorite free filters on this page, ranging from simple mix-cleaning tools to complex modulated filters for sound design.

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The best FREE filter VST plugins in 2024

• Filtron
• Frohmager
• Flux Mini 2
• BPB Dirty Filter Plus
• Filter Force Free
• TAL-Filter II
• Filterjam
• Filterstep
• Krunch
• HY-Filter4 Free
• bx_cleansweep V2

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Polyverse Filtron

Filtron is a free modulated filter plugin by Polyverse. It is available in VST, VST3, AU, and AAX formats for Windows and macOS.

At first look, Filtron is just another multi-mode filter plugin with a cool GUI design. However, it packs several capabilities you won’t find in most other filter plugins.

Filtron’s best feature is its ability to smoothly morph between high-pass, band-pass, and low-pass filter modes. I love using this to add movement to the processed audio. You can simply automate the filter mode in the DAW to get some cool-sounding transitions.

Another helpful feature is the built-in saturator. I don’t use it as a standalone saturation effect, but it works well for adding a bit of character to the filter section when needed.

The plugin’s interface design emphasizes usability, with sleek, responsive knobs and a resizable interface that scales from 50% to 200%. I also like the color scheme. It’s easy on the eyes and perfect for late-night mixing sessions.

Filtron is effective in various scenarios, from enhancing guitars in a busy mix by reducing harsh frequencies to adding grit and warmth to synths without distortion.

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Ohmforce Frohmager

Frohmager is a low-pass resonant filter with additional features that make it a fantastic choice for sound design.

Most importantly, it includes a built-in distortion effect and many modulation options. You can modulate literally any filter parameter and there are plenty of modulation sources to choose from.

Frohmager offers LFOs, envelope followers, and envelope generators, all of which can modulate each other, creating complex modulation possibilities. The modulation grid provides detailed control and randomization options, and I found it easy to use, considering the amount of available modulation options.

You can also use macros to pair multiple parameters for easier tweaking. The macros are especially handy for live use when you want to apply multiple filter tweaks with a single knob movement.

The built-in distortion can be applied before or within the filter. It is based on a rather aggressive distortion algorithm and works great for completely changing the character of a sound.

The GUI has a playful design that reminds me of vintage cartoons. It looks very unique but doesn’t prioritize style over substance. Despite the brightly colored cartoon graphics, all the controls and parameters are easy to read.

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Caelum Audio Flux Mini 2

Flux Mini 2 is a free modulated filter plugin by Caelum Audio. It is in AU, AUv3, VST, VST3, and AAX plugin formats for macOS, iOS, and Windows.

The plugin builds on the success of its predecessor, Flux Mini, by offering simple sidechain and modulation capabilities to enhance your sound with minimal effort.

Flux Mini 2 features an LFO module that targets three filter modes: low-pass (LPF), band-pass (BPF), and high-pass (HPF). It has a modern-looking interface, with controls for Cutoff, Resonance, Volume, Sync (1/32 T to 32 Bars), and a Dry/Wet Mix.

My favorite Flux Mini 2 feature is a customizable graph that lets you create or adjust LFO shapes by dragging curve points or drawing new ones. The plugin includes over 20 graph presets, ranging from subtle effects to more intense modulation types.

I also love that you can double or triple the LFO shape, thus increasing the modulation speed without changing the Sync setting. This lets you experiment with more complex modulation curves with fewer clicks.

Another cool feature is the adjustable MIDI routing that lets you retrigger the envelope or trigger one-shot modulations.

I mainly use Flux Mini 2 as a time-saving tool for adding movement and excitement to sounds without relying on DAW automation.

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BPB Dirty Filter Plus

BPB Dirty Filter Plus is a free dual-filter plugin that combines filtering and distortion. It is available for free download in VST3 and AU formats for Windows and macOS.

It features two adjustable filters (high-pass and low-pass) with slopes ranging from 12 to 48 dB/Oct, a built-in transparent compressor, and four distinct distortion modes.

The distortion modes include “Original” for tube-style saturation, “Acid” for aggressive distortion, “Dust” for vintage lo-fi sound, and “Cyber” for a bitcrushed effect.

The main control is the Dirt knob, which lets you control the amount of distortion that is applied to the resonant section of the filter. In other words, it is shaping the sound around the cutoff frequency.

The result is a focused distortion effect that sounds similar to multi-band distortion. If used in moderate settings, it can add excitement and sparkle to a certain part of the frequency spectrum while removing any unnecessary frequencies.

The plugin lets you blend the distorted signal with the clean sound using the Mix knob. This offers plenty of flexibility for various mixing applications, particularly useful with drums.

The transparent compressor helps bring out details and glue sounds without overpowering transients. It is ideal for adding character and color to audio, but Dirty Filter also works great as a heavy distortion effect.

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Filter Force Free

Filter Force Free is a free modulated filter plugin by The Wave Warden. It is available for Windows and macOS in 64-bit VST3 and AU formats.

The free version of Filter Force offers two 24 dB filters: a high-pass and a low-pass. Both filters have adjustable cutoff, resonance, gain, pan, and drive controls. The drive feature adds distortion for a more aggressive sound.

Filter Force’s forte is the versatile modulation section that lets you create up to four free-form curves to modulate any plugin parameter.

I appreciate that it’s possible to customize the modulation curve using the brush tool instead of manually adjusting control points like in most other plugins. This method is more intuitive as it lets you draw the modulation shape.

I also like the interface design. It has large controls, a clean look, and a freely resizable GUI. The built-in interactive tutorial is also great.

The full version (€50) adds over twenty filter types, four MSEGs, and a preset browser. That said, the freeware version is still a powerful modulation tool and a great option if you’re looking for a versatile free filter.

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TAL-Filter II

TAL-Filter-2 is a free filter plugin with extensive modulation capabilities, available in AU, VST, VST3, and AAX formats for macOS, Windows, and Linux.

Togu Audio Line borrowed several filter types from its TAL-NoiseMaker synthesizer, including low-pass (LP 24 dB, 18 dB, 12 dB, 6 dB), high-pass (HP 12 dB), band-pass (BP 12 dB), and notch (N 12 dB).

TAL-Filter-2 lets you modulate the stereo panning and volume in addition to the filter cutoff. This makes the plugin useful for effects like tremolo, trance gates, and stereo modulation. You can also use it to saturate or distort the input signal.

The curve editor lets you create custom modulation shapes that sync with your DAW’s tempo. This works great for creating complex basslines and pulsing leads without using DAW automation or external modulation sources.

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Audiothing Filterjam

Filterjam is a free multi-band resonant filter by Audiothing. It is available for macOS and Windows in VST, AU, AAX, and CLAP formats.

The filter splits the input audio into four frequency bands. These four components are then summed or multiplied based on the selected mode, resulting in unique, ring modulation-like effects.

The control section includes basic filter parameters such as cutoff, resonance, gain, and a mix knob, along with a 4-way mode switch that drastically alters the sound depending on how the frequency bands are processed.

Filterjam isn’t a filter plugin you’d typically use in a mix. Instead, it shines as a creative tool that can transform the original sound into something completely different.

The interface is simple, and I love that Audiothing included a randomizer for quick experimentation. I often load Filterjam on a channel and randomize its output until it produces an interesting texture.

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Audiomodern Filterstep

Filterstep is a free multi-mode filter plugin with a built-in step sequencer. It is available in VST, AU, and AAX formats for Windows and macOS, as well as a standalone desktop version and a portable iOS app.

The plugin is perfect for creating complex rhythmic filtering effects and adding movement to static sounds like pads and drones. The step sequencer syncs with your host’s tempo and lets you adjust quantization and step length.

It also includes a randomizer for generating new patterns with one click. You can store the generated sequences in one of sixteen preset slots for easy access during live performances.

Filterstep works great as a plugin, but I highly recommend checking out the iOS app. It is a great tool for developing musical ideas on a portable device.

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Hollace Krunch

Krunch is a freeware that combines filtering and saturation. It is available for macOS and Windows in AU and VST3 formats.

The plugin is based on the One Euro Filter algorithm, which is designed to reduce jitter at low speeds and lag at higher speeds by dynamically adjusting the cutoff frequency. This makes Krunch a resource-efficient way to clean up noisy signals and add warmth.

The interface is simple, with one main knob and two sliders. The Krunch dial controls the intensity of the effect, with saturation becoming more apparent at higher settings.

The Mix and Out sliders are there to help you blend wet/dry signals and compensate for output level changes. The plugin also includes oversampling (OVS) to reduce aliasing and a bypass button (BYP) for easy A/B comparisons.

The developer recommends starting with the Mix at 100% and adjusting the Krunch to achieve the desired effect.

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HY-Filter4 Free

HY-Filter4 FREE is the free version of the semi-modular filter effect plugin by HY-Plugins. It is available in VST2, VST3, and AU formats for Windows and macOS (64-bit hosts only).

The free version provides a two-filter engine with SVF and 3BP filter types and five modulation options: LFO, 2DLFO, RND, Env Follower, and XY Control. The full version offers advanced features like a multi-engine filter, 38 built-in effect units, and a grid sequencer.

The interface lets you adjust the Cutoff, Resonance, Morph, and Drive, with modulation easily assignable by dragging to parameters. The Morph knob lets you morph between LP, BP, and HP filter types.

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Brainworx bx_cleansweep V2

bx_cleansweep V2 is a free filter plugin for mixing and mastering. It is available to all users who join Plugin Alliance with a free account.

The plugin combines high-pass and low-pass filters designed to clean up unwanted frequencies in mixes. It is an ideal first-stage tool in the mixing process, and I often use it as the first insert across the mix.

The developer took inspiration from filtering systems found in high-end analog consoles like SSLs and NEVEs to create a simple utility for removing low-end mud and high-end grit.

The plugin utilizes Brainworx’s Anti-Crush Technology, which employs analog-style filter curves to avoid harsh digital artifacts like aliasing and harshness, making it sound smooth and musical. With a 6 dB per octave filter slope, we get subtle, musical filtering rather than surgical precision.

My only gripe is the joystick control which sounds great on paper, but I find it less intuitive than a pair of knobs to control the two filters. Still, I love using bx_cleansweep for its transparent sound and simplicity.

bx_cleansweep V2 is compatible with macOS and Windows systems in VST, AU, and AAX formats.

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Free Filters – Conclusion

The list above includes the best free filter plugins I tested and reviewed in my daily mixing and sound design work. If there’s another plugin you’d like to recommend, feel free to do so in the comments below.

If you’re looking for more options, check out the free Growl Filter plugin by Zayne and the excellent Eugene Filter by NUSofting.

For more freeware plugins and instruments, return to our Free VST Plugins page.