Best Mastering Plugins (Free and Paid)
Contents
You can build a professional mastering chain entirely from free plugins in 2026. You can also spend thousands on premium tools that shave minutes off every session and give you options free plugins simply don't offer. The right choice depends on where you are in your career, how many tracks you're mastering, and what specific problems you're trying to solve.
How a Mastering Chain Works
The order of your chain matters — every processor shapes the signal the next one receives. A typical mastering chain follows this battle-tested sequence:
- Corrective EQ — remove problem frequencies, shape tonal balance
- Compression — control dynamics, add glue and density
- Tonal EQ (optional) — musical moves after compression
- Stereo imaging — adjust width and mono compatibility
- Limiting — set the final ceiling and loudness
- Metering — monitor LUFS, true peak, and frequency balance
Some engineers swap steps or skip stages, but this order is a reliable starting point.
Best Mastering EQ Plugins
EQ is the most-used processor in mastering — cleaning up low-end rumble, taming harsh frequencies, and shaping tonal balance before anything else touches the signal.
FabFilter Pro-Q 4 (Paid — $189)
Pro-Q 4 is the most widely used mastering EQ for good reason. Dynamic EQ bands, mid/side processing, a real-time spectrum analyzer, and linear phase mode (which preserves the stereo image by eliminating phase shifts) — all in an intuitive interface.
Brainworx bx_digital V3 (Paid — $299)
bx_digital V3 was designed specifically for mastering. Its mid/side architecture makes it natural to widen the high end, tighten the low end in the center, or de-ess only the mid channel. The built-in mono maker collapses everything below a set frequency to mono — critical for vinyl cutting and club playback.
ZL Equalizer 2 (Free)
ZL Equalizer 2 offers dynamic bands, a real-time spectrum analyzer, mid/side processing, and an interface that rivals paid plugins. Multiple reviewers call it a legitimate free alternative to Pro-Q. If you're on a budget and can only get one free plugin from this entire list, make it this one.
iZotope Ozone 11 Equalizer (Free)
iZotope offers the EQ module from Ozone 11 as a free standalone plugin. Clean, musical EQ without the dynamic bands or mid/side of ZL Equalizer, but polished and reliable.
Best Mastering Compressors
FabFilter Pro-C 2 (Paid — $179)
Pro-C 2 gives you eight compression styles (Clean, Classic, Opto, Vocal, Mastering, Bus, Punch, Pumping). The real-time gain reduction display makes it easy to see exactly what the compressor is doing — invaluable when you're aiming for transparent dynamics control.
Waves SSL G-Master Bus Compressor (Paid — $35–$50 on sale)
The SSL G-Master Bus Compressor is the plugin version of the compressor on the SSL 4000 G console's master bus. It excels at "gluing" a mix together with simple, fast-to-dial-in controls. At Waves' frequent sales, it's one of the best value-for-money mastering compressors available.
PSP MasterComp (Paid — $149)
PSP MasterComp is purpose-built for mastering — transparent when used lightly, musical when pushed harder. The multiband mode lets you compress different frequency ranges independently.
TDR Kotelnikov (Free)
TDR Kotelnikov is the best free mastering compressor by a wide margin. It preserves tone, timbre, and punch while smoothing out dynamic range. The "Gentle" preset is a great starting point. The paid version (Kotelnikov GE, $50) adds mid/side processing, but the free version handles most mastering scenarios.
Best Mastering Limiters
The limiter determines your track's final loudness. A good one catches peaks transparently, pushes loudness without audible distortion, and provides accurate true peak detection so your master doesn't clip during encoding. For more on loudness targets, see our guide on how loud you should master your music.
FabFilter Pro-L 2 (Paid — $199)
Pro-L 2 is the most widely used mastering limiter. Eight algorithms (Transparent, Punchy, Dynamic, Allround, Aggressive, Modern, Bus, Safe), real-time LUFS metering, and true peak limiting. The Transparent algorithm handles 3–5 dB of gain reduction without audible artifacts on most material.
Sonnox Oxford Limiter v3 (Paid — $209)
The Oxford Limiter v3 includes an "Enhance" section that increases perceived loudness through psychoacoustic processing rather than just pushing the ceiling harder — more loudness without the distortion of hitting a standard limiter harder.
Slate Digital FG-X (Paid — $149)
FG-X separates transient and constant-level processing, letting you push the body louder while preserving transient peaks. Particularly effective on material with sharp transients where traditional limiting squashes the performance.
XMLimiter V2 (Free)
XMLimiter V2 is a transparent free limiter. No algorithm choices or advanced metering, but for gain reduction up to about 3 dB, it does the job cleanly.
Best Stereo Imaging Plugins
Not every master needs stereo processing — if the mix already has a balanced, wide image, adding an imager can introduce phase issues. Use it when the mix feels too narrow, the low end is too wide for club systems, or you want to subtly widen the highs for a more open feel.
iZotope Ozone Imager 2 (Free)
The Ozone Imager 2 is free and genuinely best-in-class. It splits the signal into frequency bands, lets you widen or narrow each independently, and shows a real-time correlation meter so you can catch phase problems before they cause issues.
Brainworx bx_stereomaker (Paid — $149)
bx_stereomaker creates a natural-sounding stereo field from mono or very narrow sources without comb-filtering artifacts. Niche, but invaluable when you need it.
Best Metering Plugins
Metering doesn't change your audio, but it tells you whether your processing is working. Without it, masters end up clipping on streaming platforms or sounding nothing like reference tracks.
Youlean Loudness Meter 2 (Free)
Youlean Loudness Meter 2 measures integrated/short-term/momentary LUFS, true peak, and loudness range. Includes presets for every major streaming platform. Costs nothing, does everything you need.
iZotope Insight 2 (Paid — $199)
Insight 2 adds a spectrogram, stereo field display, and intelligibility meter. Worth it if you're mastering full albums and need to match loudness, tonal balance, and stereo width across tracks.
Best All-in-One Mastering Suites
These suites bundle EQ, compression, limiting, stereo imaging, and more into one interface — convenient, though less flexible than mixing and matching individual tools.
iZotope Ozone 11 (Paid — $199–$499)
Ozone 11 is the most popular mastering suite in the world. Parametric EQ, dynamic EQ, multiband compressor, stereo imager, exciter, and maximizer — all stackable in a single window. The AI-powered Master Assistant suggests a starting chain you refine manually. Standard ($199) covers most needs; Advanced ($499) adds mid/side to more modules and codec previews.
For most producers doing their own mastering, Ozone is the single best investment on this list.
IK Multimedia T-RackS 5 (Paid — $150–$500)
T-RackS 5 takes a modular approach — a virtual rack with 40+ individual processors. Includes a standalone application for mastering without a DAW.
Brainworx bx_masterdesk Classic (Free)
bx_masterdesk Classic distills a full analog mastering chain into a simplified interface: EQ, compression, saturation, and limiting in three steps. Built for fast, good-sounding results without the learning curve.
Building a Complete Free Mastering Chain
$0
for a complete, professional mastering chain
| Chain Position | Plugin | Role |
|---|---|---|
| 1. Corrective EQ | ZL Equalizer 2 | Remove problem frequencies, shape tone |
| 2. Compression | TDR Kotelnikov | Smooth dynamics, add glue |
| 3. Tonal EQ (optional) | iZotope Ozone 11 EQ | Musical EQ moves after compression |
| 4. Stereo imaging | iZotope Ozone Imager 2 | Adjust width, check mono compatibility |
| 5. Limiting | XMLimiter V2 | Set final loudness ceiling |
| 6. Metering | Youlean Loudness Meter 2 | Monitor LUFS, true peak |
Every plugin here is genuinely good — not a "good for free" compromise. What you give up vs. paid options is workflow speed and edge-case flexibility.
When to Invest in Paid Plugins
- You're mastering frequently. Multiple tracks per week means Pro-Q 4's workflow and Pro-L 2's algorithm choices save real time every session.
- You need mid/side processing. ZL Equalizer has it, but bx_digital V3 and Pro-Q 4 make mid/side work significantly faster.
- You want a single-window workflow. Ozone's all-in-one chain with AI-suggested starting points is a genuine productivity advantage.
- Difficult source material. Harsh vocals, boomy low end, and phase issues need surgical tools that free plugins can't match.
Quick Reference: Every Plugin at a Glance
| Plugin | Category | Price | Best For |
|---|---|---|---|
| FabFilter Pro-Q 4 | EQ | $189 | Surgical and musical EQ with dynamic bands |
| Brainworx bx_digital V3 | EQ | $299 | Mid/side mastering EQ |
| ZL Equalizer 2 | EQ | Free | Full-featured dynamic EQ |
| iZotope Ozone 11 EQ | EQ | Free | Clean, musical EQ |
| FabFilter Pro-C 2 | Compressor | $179 | Versatile compression with visual feedback |
| SSL G-Master Bus Compressor | Compressor | ~$35 | Mix glue and punch |
| PSP MasterComp | Compressor | $149 | Transparent mastering compression |
| TDR Kotelnikov | Compressor | Free | Transparent wideband dynamics |
| FabFilter Pro-L 2 | Limiter | $199 | Transparent limiting with LUFS metering |
| Sonnox Oxford Limiter v3 | Limiter | $209 | Psychoacoustic loudness enhancement |
| Slate Digital FG-X | Limiter | $149 | Transient-preserving loudness |
| XMLimiter V2 | Limiter | Free | Clean, simple limiting |
| iZotope Ozone Imager 2 | Stereo | Free | Multiband stereo width control |
| Youlean Loudness Meter 2 | Metering | Free | LUFS, true peak, loudness range |
| iZotope Ozone 11 | Suite | $199–$499 | Complete mastering in one plugin |
| IK Multimedia T-RackS 5 | Suite | $150–$500 | Modular rack-based mastering |
| bx_masterdesk Classic | Suite | Free | Quick, simplified mastering chain |