Version 1.2.3 — available now

gFractor

A powerful and flexible spectrum
analyzer for modern audio production.

Free Download Explore features
Read the full manual

Spectrum, scope, goniometer, loudness, and the full picture, in one window.

VST3 · AU · Standalone · macOS, Windows, Linux · Free, no account

Introduction

See it in action

What makes it different

Tools that think like musicians

From sound design to mixing and mastering — gFractor gives you precise visual feedback and deep insight into your audio at every stage of the workflow.

01 — Advanced Analysis Modes

Three modes.
Every perspective.

Switch between Mid/Side, Left/Right, and Transient/Tone analysis to explore your signal from any angle. Monitor individual components — isolate transients from tonal content, or hear the mid and side channels in complete separation.

Mid / Side Left / Right Transient / Tone Component monitoring
gFractor spectrum analyzer with Mid/Side channel mode controls
02 — Signal Comparison

Main and sidechain,
side by side

Visually compare your main signal against a sidechain reference — instantly revealing spectral relationships between tracks. Swap main and sidechain with a single key press for rapid A/B analysis without breaking your flow.

Main signal Sidechain One-key swap Visual overlay
gFractor overlaid primary and secondary spectrum curves
03 — Stereo Analysis

Your stereo field,
fully mapped.

Comprehensive stereo visualization in one place: a goniometer for phase and imaging, a correlation meter for mono compatibility, and correlation broken down per octave — so a phase problem in the sub can't hide behind an in-phase midrange.

Goniometer Correlation meter Correlation per octave Band-pass filter
gFractor stereo analysis with goniometer, correlation and width per octave
04 — Target Save & Compare

Save a target.
Match it later.

Capture any Peak Hold curve as a reusable target and save it to a file. Load it back in any session to compare against your current track — perfect for matching tonal balance across mixes or checking a master against a reference.

Peak Hold capture Save / Load Reference overlay Cross-session
gFractor save, load and target curve controls
05 — Loudness Metering

Loudness,
to spec.

A full ITU-R BS.1770-4 / EBU R128 loudness meter sits alongside the analyzer. Track short-term and integrated LUFS, loudness range, and dynamics at a glance — with momentary, short-term, and peak maximums held since the last reset. Switch to LU to read against your delivery target, and check crest factor alongside PSR and PLR.

Short-term & Integrated Loudness Range Dynamics LU vs target
gFractor LUFS loudness metering panel

Available now

Free. No compromises.

No demo mode. No watermark. No 30-day trial.
Professional-grade tools should be in everyone's hands.

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v1.2.3 Previous versions
~/gFractor — CHANGELOG.md
$ cat v1.2.3.md
# gFractor 1.2.3
Released 2026-09-24
## New
+ LUFS / LU pills switch the loudness readouts between absolute LUFS and LU relative to a target
+ Draggable TARGET badge sets the target in 0.5 LU steps; the bar marks it as a dashed line at 0 LU
+ CREST readout: the plain peak-to-RMS ratio in dB, over the same 3 s window as the peak
+ Reset On Play restarts the loudness measurement whenever the host transport rolls (off by default)
+ The per-octave stereo chart now plots correlation per band, on an 8192-point FFT so 31.5 Hz resolves
+ Scope dB cursor: a horizontal line follows the pointer, labelled in dB relative to the lane's zero line
+ The sidechain draws in the scope as a ghost envelope beneath the main curves, so G works there too
+ Export any view as a branded 2x PNG with E or the camera pill in the header
## Changed
* New Meters preferences tab between Display and System — target level, LUFS Min / Max, Reset On Play
* Preference tabs are sized to their captions, and the panel is widened to 620 px so they fit on Windows
* An empty octave band reads zero correlation instead of painting a confident bar off noise
## Fixes
- A target curve saved at one FFT size and reloaded at a smaller one read past the end of its data
- The GHOST pill state survives a reopened editor; reference mode is dropped when the window closes
- Switching channel mode restarts the ghost trace's Transient/Tonal envelopes
Beta

Preview channel

Try the next release early.

New features, fresh fixes — and the occasional rough edge. Feedback helps shape the next stable build.

No preview build right now

The latest stable release is 1.2.3. When the next preview opens it lands here first — follow the news to catch it early.

Read the news Previous versions

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