Comparison

Paced vs HzLab

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Paced

Features
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StutterPractice helps people who stutter build fluency and confidence through structured, rhythm-based speech practice. PRACTICE MODE Add words or sentences to your personal library and practice them one at a time. A metronome guides your speech rhythm, breaking each word into syllables so you can pace yourself naturally. Adjust the tempo to match your comfort level and build up gradually. LIVE MODE Use Live Mode during real conversations or reading aloud. The metronome runs in the background through your headphones or phone speaker, keeping your rhythm steady without interrupting your flow. Enable Gradual Fade to slowly reduce the metronome over time as your natural rhythm takes over. DESIGNED FOR FLUENCY - Syllable-by-syllable guidance - Adjustable BPM from 40 to 180 - Audio, haptic, and wrist feedback options - Gradual fade-out to build independence - Clean, distraction-free interface Paced is a practice companion, not a medical device. For best results, use it alongside guidance from a speech-language pathologist.

About

HzLab

Features
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Plenty of apps will play you a “healing” frequency. This one plays the same tones — but it always shows you how far the research on that frequency has actually got, right next to the play button. ■ Start from a goal, not a number Sleep / Relaxation & Anxiety / Focus & Cognition / 40 Hz Gamma Stimulation / Pain Self-Care / Solfeggio & 432 Hz / Noise. Follow one of seven categories and you arrive at the tone you came for. No knowledge of hertz required. ■ Every tone carries its evidence rating All 38 items are labeled with a four-level rating of the human research behind them. • Moderate — several human studies or a meta-analysis • Low–moderate — clear in physiological measures, unproven clinically • Low — small, exploratory, or conflicting results • No evidence — no controlled study supports an effect specific to that frequency The player screen gives you the study year, the sample size, the conditions, and the negative findings too. It says plainly that the claim “1 Hz gives you deep sleep” is not supported, and that the study usually cited for 528 Hz had about nine participants. ■ The popular frequencies are here — honestly 432 Hz, 528 Hz, and the full 174–963 Hz Solfeggio set are all playable. They are simply labeled with the fact that no human clinical evidence supports claims like “resonates with the universe” or “repairs DNA.” We think putting the fact next to the claim is more useful than deleting the claim. ■ What's inside (38 items) • Sleep: binaural beats at 0.25 / 1 / 3 / 6 Hz, plus white, pink, and brown noise • Relaxation & Anxiety: theta binaural, 6 / 10 Hz monaural beats, 40 Hz isochronic • Focus & Cognition: white and pink noise, binaural beats at 10 / 16 / 25 / 40 Hz • 40 Hz Gamma: amplitude-modulated tone, isochronic, monaural, 60 Hz • Pain Self-Care: alpha entrainment, 40 Hz, theta binaural • Solfeggio & 432 Hz: 432 and 528 Hz plus the complete 174–963 Hz set • Noise: white, pink, brown ■ Synthesized on your device Nothing here is an audio file. Each waveform is computed sample by sample as it plays, so there is no loop seam and no compression artifact, however long you leave it running. Supports pure tones, binaural beats, monaural beats, isochronic tones, amplitude modulation, and three noise colors. ■ Custom frequency generator Pick a method, then dial the carrier from 20 to 1000 Hz and the beat from 0.25 to 60 Hz, with presets at 40, 100, 250, 432, and 528 Hz. ■ Night mode, for bedtime Beyond System, Light, and Dark, a Night mode takes the screen almost to black, with the dimming on a slider. The sleep timer runs 15, 30, 60, or 90 minutes, and background audio keeps playing with the screen off. ■ Seven languages Japanese, English, Simplified Chinese, Korean, Spanish, French, and German — including every research note. ■ Nothing collected, nothing sent • No account, no sign-in • No analytics, no tracking • No access to the microphone, camera, location, or health data • No connection needed at all — every feature works in airplane mode The only thing stored on your device is your appearance mode and dimming level. ■ Before you use it This app is a sound generator, not a medical device. It is not intended to diagnose, treat, or prevent any condition, and it is not a substitute for care from a physician or other professional. Binaural beats physically require stereo headphones or earphones. To protect your hearing, use the lowest volume that serves your purpose. Stop using the app if you feel discomfort, headache, tinnitus, or worsening symptoms. The research summaries shown in the app organize literature published as of August 2026 and do not guarantee any particular effect.

Screenshots

Paced4 screens
HzLab4 screens

Verdict

The call

The clearest difference is price: Paced at Free against HzLab's $4.99. On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Paced is free to download; HzLab costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Scorecard1 real difference · 5 level
Paced versus HzLab: the parameters behind the verdict, then further details
ParameterPacedHzLab
PriceFree — better$4.99
Update frequencyEvery 2 months—
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS17.617.0 — better
Further details — not scored
Size5 MB2 MB
Age rating4+4+
DeveloperAbbas YousefzadehCode and DESIGN inc

In-app purchases

None

Paced

No in-app purchases

None

HzLab

No in-app purchases

Questions

Is Paced free?
Paced is free to download, with no in-app purchases.
Is HzLab free?
HzLab costs $4.99, with no in-app purchases.
Do Paced or HzLab have ads?
Neither Paced nor HzLab shows ads.

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