A 16-point LED strip pinned to the edge of your Mac's screen, floating above every window — fullscreen included. It never takes focus, it never steals clicks, and it reads VU, PPM, and LUFS with the ballistics each one is supposed to have. You work in OBS, in Logic, in the game. Your levels stay where you can see them.
What flexMeter is about
A 16-point strip on whichever edge you pin it to. It rides above every window — including fullscreen apps — follows you across Spaces, and passes clicks through to whatever is underneath. You'll forget it's a panel until your levels move.
VU with broadcast-standard 300ms integration. PPM with IEC 60268-10 Type I fast-attack ballistics. LUFS with ITU-R BS.1770-4 K-weighting and momentary, short-term, and integrated readings. Real standards, real ballistics — not a colourful gradient someone called a meter.
Everything lives in the menu bar and on the strip itself. Right-click for quick settings, keyboard shortcuts for the rest. Launch at login, set a position, and it runs all day without stealing a single focus event.
Meter modes
The mode you pick changes the ballistics, not the drawing. VU reads average loudness the way broadcast engineers already know. PPM is a peak meter that actually catches peaks. LUFS is the one streaming platforms check your show against when nobody is watching. All three use the correct smoothing and decay — we looked up the numbers so you didn't have to.
Exponential moving average with 300ms integration. Peak decay at 26 dB/s.
The classic VU response broadcast engineers grew up on. Slow enough to read at a glance, fast enough to catch the shape of a voice. We didn't reinvent it — we just shipped it with the ballistics it's supposed to have.
Use it when: Mixing voice, monitoring a stream, running levels on anything where average loudness is what you actually care about.
IEC 60268-10 Type I peak programme meter. Fast attack smoothing, 7 dB/s decay.
A PPM catches transient peaks that a VU politely ignores. If a snare or a gate-slam is going to clip, PPM sees it before you do and sits on it long enough for you to react.
Use it when: Tracking drums, capturing dialogue in rooms with surprises in them, or anywhere a single sharp transient would ruin the take.
ITU-R BS.1770-4 with K-weighting, 100ms step, 75% overlap. Momentary, short-term, integrated.
Cascaded biquads handle K-weighting (high-shelf + RLB). Gated loudness runs over 400ms (momentary), 3s (short-term), and the full session (integrated). Absolute gate at -70 LUFS. Platforms care about this number. Now you can, too.
Use it when: Mastering a podcast, checking a stream against a platform target, or meeting a broadcast spec without opening a plugin.
Loudness presets
LUFS mode ships with the three targets most people actually need, and draws a cyan reference line on the strip at whichever one you pick. You can see, at a glance, whether your integrated reading is sitting where it's supposed to.
Reset the integrated measurement between takes from the settings panel or the right-click menu. No plugin, no host, no extra window.
The loudness target most streaming services are quietly measuring you against.
The target Apple's podcast and music teams publish, and the one to hit if you want to stop hearing "your podcast is quiet."
EBU R128 / ATSC A/85 territory. The number your station's loudness log is looking for.
Features
Nine of the 24 that ship in 1.0 — the rest live on the features page. Every one earns its place by staying out of your way until the levels actually move.
Per-channel RMS rendered as 3-point segments with 1-point gaps, clamped to -60 to 0 dB. Colours step from green to amber to red so a clip is a clip whether you glance or stare.
See every channel without taking your eyes off the app you're actually working in.
Broadcast-standard 300ms integration via an exponential moving average (alpha 0.3). Peak decay at 26 dB/s. The ballistic response VU meters are supposed to have.
The meter your ears are already calibrated to.
IEC 60268-10 Type I peak programme meter. Smoothing alpha 0.6 for a fast attack, 7 dB/s return. Built to catch the transients VU meters read past.
Short, sharp peaks stay visible long enough to react to.
ITU-R BS.1770-4 loudness. Cascaded biquads for K-weighting, 100ms step with 75% overlap, absolute gate at -70 LUFS. Momentary (400ms), short-term (3s), and integrated (full session) all visible in the settings panel.
Three loudness readings without opening a plugin host.
A bright segment marks the highest level per channel for 1.5 seconds before decaying at the active mode's return rate. Peaks above -6 dB render red, below -6 dB render white.
See where the spike actually was, not just where the meter is now.
Sample-peak tracking per channel with slow decay. Reported in dBFS alongside momentary, short-term, and integrated values.
Catch inter-sample peaks that a gated loudness number would otherwise miss.
One-click targets for YouTube/Spotify (-14), Apple Music/Podcast (-16), and Broadcast (-23). A cyan reference line draws on the strip itself at the chosen level.
Aim for a number, not a feeling.
One action in the settings panel or the right-click menu clears all LUFS accumulators, biquad state, and the true-peak value. Available only in LUFS mode, because it shouldn't be anywhere else.
Start every take on a clean integrated measurement.
CoreAudio enumerates every input device — built-in mic, USB interface, Thunderbolt rig, virtual audio. Device lists appear in the menu bar settings and the right-click menu.
Whatever you already plug in will show up here.
How it fits into a session
Pin the strip to the right edge. Fire up the game. OBS can go behind every window it wants — your mic levels stay at the edge of your monitor, click-through, never flashing the desktop mid-stream when you glance over.
Four-person call, four channels, four bars. Switch to LUFS, pick the -16 preset, and watch the integrated number settle in as the episode goes long. Hit Reset Integrated at the top of each take so the math starts clean.
PPM mode on, -23 LUFS preset as the reference line. The strip rides over your automation software, stays across Spaces, and gives you a standards-correct read without a rack.
Virtual audio device comes in from a capture rig; flexMeter picks it up through CoreAudio like any other input. Pin the strip to the secondary display and keep the main monitor for work.
Opacity at 30%, top edge, VU mode. A room-tone meter that disappears into the wallpaper and only shows up when something in the room gets loud enough to matter.
Questions we get a lot
No. It reads levels from your input device in real time and does not record, store, or transmit any audio. macOS requires microphone permission for any app that opens an audio input — flexMeter installs a tap on the input device to calculate levels, and that's all.
VU (300ms integration) is slow and reads average loudness — it's what broadcast uses for voice. PPM (IEC 60268-10 Type I) has a fast attack and slow return, so it catches short transient peaks a VU reads past. LUFS (ITU-R BS.1770-4) uses K-weighted gated loudness and is the measurement streaming platforms actually check against — momentary, short-term, and integrated readings all update in real time.
M (Momentary) is loudness over the last 400ms — it reacts almost immediately. S (Short-term) is loudness over the last three seconds, which smooths out brief fluctuations. I (Integrated) is the gated loudness across the whole measurement period — the number to match against a platform target. Hit Reset Integrated to start a new measurement at the top of a take.
Switch to LUFS, pick the preset that matches your target — YouTube/Spotify (-14), Apple Music/Podcast (-16), or Broadcast (-23). A cyan reference line appears on the strip at that target level. Aim to keep your integrated (I) reading near it.
Green below -12 dB (safe). Yellow between -12 and -6 dB (warm). Red above -6 dB (approaching clipping). Peak hold indicators turn red above -6 dB too, so a glance tells you the same story.
Yes. flexMeter detects every input device macOS sees via CoreAudio — built-in mic, USB interface, Thunderbolt interface, virtual audio device. It supports 1 to 8 channels per device.
flexMeter notices, switches the engine over to the system default input, and shows a brief status message. It does not crash, quit, or freeze the strip.
The first release is shipping, the beta is open to the people who want one, and the inbox has humans in it. Tell us what you record, stream, or broadcast — and where the meters in your current setup are hiding.
No waitlist form. No tracking. No recording — of your audio, or of your visit.