Sound Analysis Tools
Pitch Detector Tools

Free Sound Analysis Tools: dB, LUFS & Mic Tests

Last updated: October 31, 2026 · Written by the Pitch Detectors Editorial Team

These free sound analysis tools measure real-time sound levels, check loudness in LUFS, test your microphone, and visualize audio as waveforms. Everything runs in your browser — no downloads, no sign-up, and no audio ever leaves your device.

Decibel Meter

Measure real-time sound levels using your device microphone. Useful for noise monitoring, room acoustics, and environmental sound analysis.

Loudness Meter (LUFS)

Measure real-time audio loudness in LUFS. Track momentary, short-term, and integrated loudness for podcasts, audiobooks, and streaming audio.

Microphone Test

Test your microphone online to check volume levels, background noise, echo, and real-time audio input without installing software.

Audio Waveform Visualizer

Visualize audio waveforms in real time using your microphone or sound input. No software installation required.

Key Takeaways

  • 4 free tools: Decibel Meter, Loudness Meter (LUFS), Microphone Test, and Audio Waveform Visualizer — all running on your device's microphone.
  • dB, dBA, and LUFS measure different things: dB SPL is raw sound pressure, dBA weights it for human hearing, and LUFS measures perceived loudness over time.
  • Browser meters are excellent relative meters (is it getting louder?) but are not calibrated SPL meters — your mic's sensitivity is unknown to the page.
  • For hearing safety, NIOSH recommends no more than 85 dBA averaged over 8 hours, halving allowed time for every 3 dB increase.
  • No audio is recorded, uploaded, or stored — analysis happens locally in your browser.

What Is Sound Analysis?

Definition: Sound analysis is the measurement of audio signals to understand their level, loudness, clarity, and noise content. Online sound analysis tools perform these measurements in your browser using your device's microphone and the Web Audio API — no installed software needed.

Use them to check whether a room is too loud, verify a microphone works before a call or stream, confirm a podcast's loudness hits platform targets, or simply see what sound looks like as a waveform. They answer "how loud is this, really?" with a number instead of a guess.

The 4 Tools in This Category

Decibel Meter — measures real-time sound levels in dB through your microphone. Useful for noise monitoring, checking room loudness, and environmental sound checks.

Loudness Meter (LUFS) — measures perceived loudness in LUFS (momentary, short-term, and integrated), the unit streaming platforms and podcasts standardize on.

Microphone Test — verifies your mic captures clean audio at usable levels: checks input volume, background noise, and delay without installing anything.

Audio Waveform Visualizer — draws your sound as a live waveform, making amplitude, clipping, and silence visible.

How to Choose the Right Tool

Your question Use this tool
How loud is this room right now? Decibel Meter
Is my podcast at the right loudness for platforms? Loudness Meter (LUFS)
Is my microphone working properly? Microphone Test
What does my voice look like as sound? Waveform Visualizer

dB vs. dBA vs. LUFS: Three Numbers, Three Jobs

People say "decibels" for three different measurements. Mixing them up is the most common loudness mistake.

Unit Measures Use it for
dB SPL Raw sound pressure vs. 20 micropascals Physical loudness of a space (the Decibel Meter)
dBA Sound pressure weighted for human hearing Hearing safety, noise regulations, workplace limits
LUFS Perceived loudness over time (ITU-R BS.1770) Podcasts, streaming, broadcast delivery (the Loudness Meter)

Everyday reference points: a whisper is about 30 dB, normal conversation about 60 dB, a rock concert about 110 dB. Because the decibel scale is logarithmic, 70 dB isn't "a bit louder" than 60 dB — it carries ten times the sound energy.

TECHNICAL SPECIFICATION common sound levels on the logarithmic decibel scale INPUT CRITERIA Standard Parameters BASELINE SPECS DSP COMPUTATION Algorithmic Conversion IN-BROWSER DSP OPTIMAL OUTPUT Calibrated Value ACCURATE RESULT logarithmic loudness ladder — whisper 30 dB, conversation 60 dB, concert 110 dB — showing each
Diagram: common sound levels on the logarithmic decibel scale

How Loud Is Too Loud? OSHA and NIOSH Limits

Hearing damage depends on both level and duration. Two US authorities define the limits — and they disagree on the math, which is worth knowing.

OSHA (legal requirement) NIOSH (health recommendation)
8-hour limit 90 dBA (permissible exposure limit) 85 dBA (recommended exposure limit)
Action level 85 dBA — triggers a hearing conservation program —
Exchange rate 5 dB: every +5 dB halves allowed time 3 dB: every +3 dB halves allowed time
At 100 dBA 2 hours allowed 15 minutes allowed

The NIOSH 3 dB exchange rate follows physics (every 3 dB doubles sound energy); OSHA's 5 dB rate is the legally enforceable minimum in US workplaces. For personal listening, the conservative move is the NIOSH math: 85 dBA for 8 hours, 88 for 4, 91 for 2. Sources: OSHA 29 CFR 1910.95; NIOSH noise criteria.

LUFS Targets: What Platforms Expect

Streaming services normalize everything to a target loudness, turning louder tracks down (and sometimes quieter ones up). Mastering near the target means your audio plays at the intended level instead of being adjusted.

Destination Integrated loudness target True peak ceiling
Spotify / YouTube (music) −14 LUFS −1 dBTP
Apple Music −16 LUFS −1 dBTP
Apple Podcasts −16 LKFS −1 dBFS
Podcasts (AES TD1008 guidance) −18 LUFS −1 dBTP

Check your mix with the Loudness Meter before publishing: play the finished episode or track through it and compare the integrated reading to your platform's target. Note that older advice citing −16 LUFS stereo / −19 LUFS mono comes from the superseded AES TD1004 — the current AES TD1008 guidance centers podcast content at −18 LUFS.

Why Browser Meters Aren't Calibrated SPL Meters

An honest limitation worth understanding: a $2,000 Class 1 sound level meter is calibrated against a known reference tone so its dB readings are absolute. A browser page has no idea how sensitive your microphone is — a phone mic, a headset, and a USB condenser all report different raw levels for the same room.

What the tools can do reliably: relative measurement. "The room got 10 dB louder when the AC kicked in" is trustworthy; "the room is exactly 52 dB" is approximate. Two more gotchas: many devices apply automatic gain control (AGC) that fights the meter — disable mic "enhancements" in your OS settings for steadier readings — and browsers can't defeat a mic's own noise floor, typically 30–40 dBA on built-in mics.

Who These Tools Are For

Podcasters and streamers verify mic health and loudness before recording.

Musicians check rehearsal-room levels against hearing-safety limits.

Remote workers and gamers test microphones before calls and streams.

Teachers and students visualize sound and run no-install acoustics demos.

Limitations

  • Not calibrated instruments. Readings are approximate in absolute terms; trust them for comparisons, not compliance measurements.
  • OS audio processing interferes. Automatic gain control, noise suppression, and "enhancements" can skew readings — turn them off for measurement.
  • Mic quality bounds everything. Built-in mics have higher noise floors and uneven frequency response versus measurement microphones.
  • No legal standing. These tools can't certify workplace noise compliance — that requires calibrated equipment and a qualified hygienist.

Browser Tools vs. Dedicated Meters

These browser tools Phone SPL app Calibrated SPL meter
Cost Free Free–$30 $200–$2,000+
Calibration None Rough (per-device) Traceable to standards
Best for Quick checks, mic tests, LUFS Casual spot checks Compliance, professional acoustics
Needs Browser + mic permission Install Hardware + calibrator
WAVEFORM ANALYSIS peak level is not perceived loudness — why LUFS exists Original Reference Signal UNPROCESSED NORMALIZED Processed Output Signal waveform vs. loudness — the same audio shown as an amplitude waveform (peaks) and as a LUFS lou
Diagram: peak level is not perceived loudness — why LUFS exists

Frequently Asked Questions

Four free tools: the Decibel Meter (real-time sound levels in dB), the Loudness Meter (perceived loudness in LUFS — momentary, short-term, and integrated), the Microphone Test (checks your mic's volume, noise, and delay), and the Audio Waveform Visualizer (draws your sound as a live waveform).

They are accurate for relative measurement — detecting that a room got louder, or comparing two mics — but not calibrated in absolute terms, because the page doesn't know your microphone's sensitivity. Treat readings as good estimates (±a few dB) rather than lab measurements, and disable OS mic "enhancements" for steadier results.

dB SPL measures raw sound pressure; dBA applies a weighting curve matching human hearing (used for safety limits); LUFS measures perceived loudness over time per ITU-R BS.1770 (used by streaming platforms). Use the Decibel Meter for room levels, safety tables in dBA, and the Loudness Meter for anything you publish.

NIOSH recommends no more than 85 dBA averaged over 8 hours, with allowed time halving for every 3 dB increase — so 88 dBA for 4 hours, 91 for 2, 94 for 1. OSHA's legal limit is 90 dBA over 8 hours with a 5 dB exchange rate. For headphones, if someone next to you can hear your music, it's too loud.

No. All analysis runs locally in your browser via the Web Audio API — audio is measured in real time and never recorded, uploaded, or stored on any server. Closing the tab ends the session completely, which is why the tools can check sensitive environments without privacy concerns.

Apple Podcasts specifies −16 LKFS with peaks under −1 dBFS. The AES TD1008 guidance centers podcast-type content at −18 LUFS. Either way, play your finished episode through the Loudness Meter and compare the integrated reading — consistency across episodes matters more than hitting one exact number.

Open the Microphone Test, grant permission, and speak at normal volume. You should see the level meter respond strongly without constantly hitting maximum (clipping), hear yourself clearly in the playback check, and see minimal movement on the meter during silence (low background noise). If the meter barely moves, check OS input volume and that the right device is selected.

Yes — they work on Android and iOS in modern browsers with microphone permission. Note that phones apply aggressive audio processing and their mics vary widely, so mobile readings are best for rough checks ("is this venue painfully loud?") rather than precise measurement.

A waveform plots amplitude over time — it shows how loud sound is moment to moment, and reveals clipping (flattened peaks) and silence. A spectrogram plots frequency over time, showing which pitches are present. The Waveform Visualizer shows the former; it's the right view for checking levels and spotting distortion.

Real environments are noisy — HVAC, traffic, and reflections make levels fluctuate constantly, which is normal. If the meter swings wildly in a quiet room, your OS is likely applying automatic gain control: disable mic "enhancements" or "AGC" in system sound settings. Professional meters offer fast/slow response settings to smooth readings; holding the device still also helps.