Sonible has released puffer:fish, a free saturation plugin for macOS and Windows that wraps harmonic distortion in a colorful, character-driven interface.
We’ve seen plenty of one-knob saturation tools over the years, including the super popular Softube Saturation Knob, among countless other freebies.
puffer:fish follows the same concept but approaches it from a different angle, at least in terms of interface design. Instead of presenting saturation in technical terms, it makes the saturation more playful and visual.
So, unless it’s already clear from the screenshot, each saturation mode is represented by a different cartoon fish. But how on earth (or sea) does a fish saturate your audio?
There’s a single main control called Puffiness. When you turn it up, it increases harmonic content, density, and overall attitude. As you turn the knob further, the selected character inflates and changes its expression, making the whole thing feel more playful than your average saturation plugin.
You can change the saturation style by selecting a different character.
Tinyfin adds gentle harmonics that thicken the signal and increase perceived loudness without dramatically altering the tone. It’s a good overall pick for vocals, pads, guitars, keys, and buses when you want a bit of glue and warmth rather than obvious distortion.
Spikeskin is the opposite end of the spectrum. Here, the sound becomes much more gritty and aggressive. It’s a good fit for drums or basses that need more bite and synths that should cut through a mix.
Twitchgill sits somewhere in between. At lower settings, I love how it adds a bit of presence, but when you push it harder, the saturation becomes more unpredictable. It’s a decent medium-intensity option that works well for sound design and loops.
I’ve noticed a growing trend toward this kind of interface design. We recently covered Sound Soup, another plugin that uses a game-inspired GUI to make complex processing feel less intimidating. puffer:fish follows a similar philosophy, making saturation more approachable for newer producers.
Personally, I already have a handful of go-to saturation plugins, including our own free BPB Saturator, so this isn’t something I’d reach for every day.
But I’m not really the target audience.
If you’re just starting out and want an easy way to add warmth without worrying about gain staging or decibel values, puffer:fish makes that process feel fun.
That could also be its only real drawback: you won’t necessarily learn much about the technical side of mixing. Then again, if your main goal is to make music that sounds good rather than dive deep into engineering theory, that’s a perfectly valid approach.
puffer:fish is free to download from the Sonible website. You’ll need to enter your email address and agree to the terms to receive your license.
The plugin is available in VST, VST3, AU, and AAX formats for macOS (10.14 and higher, including Apple Silicon) and Windows 10 (64-bit), with support for sample rates up to 192 kHz.
Download: puffer:fish (FREE)
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Last Updated on February 18, 2026 by Tomislav Zlatic.
