Freeware - CRQL Anina Spectral Resonance Supression VST Plugin

https://crql.works/downloads/anina/

Free spectral resonance suppression

Just like most CRQL products, this plugin utilizes spectral processing. This gives ANINA a minimum of 256 bands of compression. While this introduces some latency (11ms on average), the trade-off for accuracy and speed is well-worth it in our opinion. Use lower blocksizes for a tighter feel, and higher blocksizes for better frequency resolution. Even when it seems like it's not processing, you may experience subtle pre-ringing and very slight changes in timbre and transients. The quirks of spectral processing.

Freeware - Woodstock Audio Waveform Compressor VST Plugin

https://woodstockaudio.com/products/waveform-compressor

Free compressor with high-res dynamic visualiser and VCA/Optical modes.

Freeware - Polarity-MD VST Plugin

https://polarity.productions/polarity-md/

Four-band dynamics with upward + downward compression, per-band clipping. Works on Windows, macOS, and Linux in VST3, CLAP, and LV2.

Freeware - Discreet Signals 8TT VST Plugin

https://discreetsignals.com/products/8TT

An 8-band OTT with a great UI. Intuitively shape the dynamics of your sound without needing to learn an old, cluttered interface. Everything on the screen is draggable. Drag between two bands to adjust the frequency crossover, and keep dragging to remove a band entirely. To create a new band, just double-click one to split it into two. Drag a handle to adjust the threshold, or drag the body of the band to change its ratio. If you need a specific value, right-click any control and its value box will become editable. For pro users, enable sidechain mode to duck or expand relative to another track, or turn on up to 8x oversampling.

Freeware - FirComp2 VST Plugin

https://jonvaudio.gumroad.com/l/fircomp2

Ultra clean peak compressor/limiter with punchy attack, musical release, and optional lookahead smoothing, for tracks or busses. Zero/low latency and low CPU. This plugin includes download in all the following formats, plus access to future updates: 64-bit VST3 for Windows, Intel/M1 64-bit VST3 for Mac OSX 10.13+, and Intel/M1 64-bit Audio Unit (AU2) for Mac OSX 10.11+.

Freeware - Variety of Sound Feenstaub TC VST Plugin

https://varietyofsound.wordpress.com/2025/02/14/feenstaubtc-released/

Features: 

Variable-Mu compression for smooth, musical dynamics 

Intuitive and effortless timing control 

Tape-style saturation and harmonic coloration 

Transformer coupled circuit design 

Seamless blending of compression, saturation, and tone shaping

Windows Only

Freeware - Chris Liepe Vocal Menace

https://www.mymusicalvoice.com/p/vocal-menace-by-chris-liepe

ALL-IN-ONE Vocal Processing 

 -Multi-stage compression and limiting (no clipping) 

 -Several flavors of progressive drives and distortions 

 -Air and EQ 

 -A unique approach to Reverb 

 -Tempo sync'd and variable Delay 

 -Easy internal effects side chain

Freeware - AP Mastering Compview VST Plugin

https://www.apmastering.com/compview/

Designed to inspect the gain reduction curvature of compressors

Requires a special test tone, supplied with the plugin

Open source

Freeware - Outobugi VST Plugins

https://outobugi.com/

Refire, Dynastia, Clamp, Wave, Extend, Dynastor, Termos, Dualcut, Toner

Freeware - Tin Brook Tales TLS 1295 LEA Free Compressor VST Plugin

https://www.kvraudio.com/forum/viewtopic.php?f=6&t=558511

Opto LA2A Inspired compressor, 32/64bit Windows VST2 and Linux only! No Mac version.

Freeware - Analog Obsession ATONE VST Plugin

https://www.patreon.com/posts/atone-102446579

A Channel Strip with A-Type EQ, Filters and 436 style Compressor 

It has lots of capabilities for tone shaping with its own custom design and internal routing.

There is no line or mic preamp as an input module but INPUT knob will drive EQ circuit's Gain Trim to get nasty op-amp saturation. 

Compressor section based on 436c with extra modifications. Compressor has AMOUNT knob to compression and make-up gain. So, it will be gain compensated.

Freeware - Viator DSP Duplex Comp Lite Version VST Plugin

https://viatordsp.gumroad.com/l/ihpwx

Free Version of Duplex Comp 

Free version does not contain: factory presets (plugin state still saves, though) 

Oversampling 

User manual built into the plugin interface 

Duplex Comp combines two serially cascading compressors, followed by a limiter, into one efficient package. This plugin streamlines a popular mixing method—employing multiple compressors in series, each with different settings—by consolidating the entire process into one convenient interface.

Freeware - Kiive Audio XTMax Compressor VST Plugin

https://www.kiiveaudio.com/products/xtmax

One of the most iconic sounds in hardware compression, now at your fingertips for free!

Freeware - Bertom Audio Vocal Compressor VST Plugin

https://www.bertomaudio.com/vocal-compressor.html

Vocal Compressor is a simple compressor plugin optimized for speech and singing voice. It is heavily inspired by how mastering limiters work and features the same kind of lookahead (about 1ms) and program dependency but in a soft knee compression context. Additionally, the "HF Sens" sidechain filter allows you to fine-tune the sensitivity to high frequencies. It is similar to what you can find on the back of a famous optical compressor.

Freeware - Venn Audio Free Suite VST Plugins

https://www.vennaudio.com/free-suite/

Free Suite is a completely free, performant, light weight, resizeable, zero fuss set of cross-platform audio plugins. All the tools needed to fully mix a track to professional standards. No registration needed, simply download and enjoy! Free Suite is available for Windows, Mac, Mac M1 native and Linux, in VST3, AU and AAX formats.

Freeware - Viator Bedroom Compressor MkII VST Plugin

https://viatordsp.gumroad.com/l/sbnuyp

Elevate your sound to new heights with the Bedroom Comp MkII. With a perfect blend of VCA and Opto compression models, this plugin gives you precise control and an analog touch for a polished and professional sound.

Freeware - Focusrite Legacy Plugins (Scarlett and Midnight) VST Plugins

https://downloads.focusrite.com/focusrite/focusrite-plug-ins

Focusrite legacy plugs have gone freeware. 32 bit only.

Freeware - Kilohearts Essentials Bundle VST Plugins

https://kilohearts.com/products/kilohearts_essentials

 

Kilohearts Essentials is a free collection of extremely useful effects which can be used as regular plugins in your DAW or loaded as Snapins in any Kilohearts Snapin Host.

Freeware - Kiive Audio Xtressor NUKE VST Plugin

https://www.kiiveaudio.com/plugins/Xtressor-NUKE-p498505074

 

NUKE may be Xtressor’s little brother, but he’s big enough to stand on his own! Make your drums explode with this gritty compressor, and use its 3 release modes to add edge and punch to your mix. Plus the adjustable Sc hpf makes NUKE super versatile- throw it on any mix!

Freeware - Auburn Sounds LENS Free Edition VST Plugin

https://www.auburnsounds.com/products/Lens.html

LENS is a spectral dynamics processor with unbelievable punch and clarity.
Multi-band compression without cross-over phase shifts.
EQ with constant phase without ringing.
Up to 64 companders, all working together on a stereo signal.
Simultaneous control of sidechain EQ and output EQ.
Removing information that is masked by nearby components.
Clean "Over The Top" multiband upwards compression.