Both apps estimate urine volume from the sound of urination. The difference is where that recording goes. Bladder Journal analyses it on your iPhone and never uploads it. Bladderly uploads it and calculates the volume on its servers, and its privacy policy lists urination audio as sensitive data that may be processed in the United States, South Korea and other countries. Bladder Journal is also the stronger everyday diary: you log on the iPhone or straight from the Apple Watch, reminders and Journey keep the diary complete, it syncs with Apple Health, and the PDF and CSV report for your doctor is free. Bladderly charges $1.99 for each PDF export on its free plan and has no Apple Watch app. Paid plans are where the gap is widest: Bladderly's unlock sound-based volume and export, while Bladder Journal PRO adds AI insights, predictive Smart Alerts and AI Chat on top of on-device Audio Analysis. Bladderly's main advantage is Android support.
Where Your Recordings Go
Both apps listen to you urinate. A recording of that is about as personal as health data gets, and the two apps treat it in opposite ways.
| Bladder Journal | Bladderly | |
|---|---|---|
| Where the sound is analysed | On your iPhone, in real time | On Bladderly’s servers, once your phone is online |
| Does the recording leave your phone? | Never | Yes. It is stored in the app until you are connected, then processed online |
| What the privacy policy says | “No audio recordings are ever stored on your device or transmitted to any server” | Lists “audio data limited to urination sounds” as sensitive information it processes |
| Cloud providers named in the policy | None involved in Audio Analysis | Amazon Web Services and Google Cloud Platform |
| Where it may be processed | Your iPhone | “the United States, South Korea, and other countries” |
| How long it may be kept | Nothing is kept: the audio is discarded after analysis | “as long as it is necessary”, and no longer than you have an account |
| Volume without internet | Yes | No. The volume is calculated once you are back online |
Bladderly's App Store privacy label lists only contact info, usage data and diagnostics. It does not list audio data or health data, although its privacy policy names both as sensitive information it processes.
With Bladder Journal there is no recording on a server to keep, share, move between countries or lose. The safest recording is the one that never leaves your phone.
Sources, checked September 25, 2026: Bladderly Help Center, “Can I use Sound Input without internet access?”; Bladderly Privacy Policy (effective February 11, 2025), sections 1, 4, 7 and 8; Bladderly's App Store privacy label; Bladder Journal Privacy Policy.
The Key Difference: The Everyday Experience
Bladder Journal
Built for logging every void
- Log on the iPhone or straight from the Apple Watch, which works offline
- Free daily, toilet and hydration reminders
- Journey keeps you on track with your daily habits
- Free PDF and CSV report for your doctor
- Audio Analysis estimates volume from sound on the iPhone, nothing uploaded
- Two-way Apple Health sync, with entries linked to your workouts
Bladderly
Built around sound-based volume
- iPhone, iPad and Android; no Apple Watch app
- Sound-based volume estimate is paid
- Recordings are uploaded and processed on its servers
- Volume is only calculated once you are online
- PDF export costs $1.99 each on the free plan
What Paying Gets You
Both apps have a free tier and paid plans. What the money buys is very different.
Bladder Journal PRO
From $2.99 a week, or $29.99 a year for everything
- Audio Analysis: volume from sound, processed on your iPhone
- Deep Insights: AI summaries of the patterns and triggers in your diary
- Smart Alerts (Yearly PRO): predicts bathroom timing, safe windows for activities and travel, and dehydration risk
- AI Chat (Yearly PRO): ask questions about your own data
Free without PRO: the full diary, Apple Watch app, reminders, Journey and the PDF/CSV report.
Bladderly premium
$4.99 to $9.99 a month, $24.99 to $69.99 a year, or a $4.99 3-day pass
- Sound-based volume: recordings processed on its servers
- Diary export: otherwise $1.99 per PDF on the free plan
Its pricing page lists these two benefits. Its App Store listing describes insights as a possible future feature.
Bladderly's published research is about one thing: how closely its algorithm estimates volume. Bladder Journal PRO goes further, into what your diary means: the patterns, the likely triggers and what to expect next. Deep Insights and Smart Alerts have been refined release after release since 2025, with input from health practitioners and feedback from real users.
Full Feature Comparison
| Feature | Bladder Journal | Bladderly |
|---|---|---|
| Apple Watch | Full companion app, works offline | No |
| Report for your doctor | Free (PDF + CSV) | $1.99 per PDF on the free plan; included in paid plans |
| Volume from sound | On your iPhone, never uploaded (PRO) | Uploaded, processed on its servers (paid); advertises 96% accuracy |
| Reminders | Daily, toilet + hydration (free) | — |
| Progress tracking | Journey (all users) | — |
| Urgency Tracking | 4-level scale | — |
| Stream Strength | Strong / Intermittent / Weak | — |
| Fluid Intake | Type + amount | Yes |
| Leakage Tracking | Severity + pad changes | Yes |
| Charts | 10 types + Bubble Heatmap | — |
| Apple Health | Two-way sync + workout linking (free) | — |
| Widgets | Home + Lock Screen | — |
| AI Insights | Deep Insights + AI Chat | — |
| Smart Alerts | Yes (AI predictions) | — |
| Urine Color | 7-level chart | — |
| Price | Free core / $5.99/mo | Free manual log; paid plans from $4.99/mo; 3-day pass $4.99 |
| Platform | iOS only | iOS + Android |
"—" means Bladderly's App Store listing does not mention it. Prices are US App Store prices, checked September 25, 2026.
Which App Should You Choose?
Choose Bladder Journal if you:
- ✓ Want a diary that is easy to keep up with, on iPhone and Apple Watch
- ✓ Want reminders and progress tracking to keep your diary complete
- ✓ Want a free PDF/CSV report for your doctor (no paywall)
- ✓ Want volume from sound without your recordings ever leaving your phone
- ✓ Want your diary to stay on your device
- ✓ Need detailed urgency and stream strength tracking
- ✓ Want AI insights and Smart Alerts (PRO)
- ✓ Value Apple Health integration
Choose Bladderly if you:
- ✓ Use an Android device
- ✓ Need one diary across Android and iPhone
Frequently Asked Questions
Which is better for keeping a bladder diary — Bladder Journal or Bladderly?
For iPhone users, Bladder Journal. A diary only helps if you log every void, and Bladder Journal is built for that: you log on the iPhone or straight from the Apple Watch, reminders prompt you to log and to drink, Journey keeps you on track with your daily habits, and the PDF and CSV report for your doctor is free. Both apps estimate volume from the sound of urination, but Bladder Journal does it on the iPhone, while Bladderly uploads the recording and calculates the volume on its servers. On Bladderly's free plan each PDF export costs $1.99. Bladderly runs on Android, which Bladder Journal does not.
Is Bladderly free?
Partly. Bladderly's free plan is a manual diary. Estimating volume from sound needs a paid plan ($4.99 to $9.99 a month or $24.99 to $69.99 a year on the US App Store, or a $4.99 3-day pass), and on the free plan each PDF export costs $1.99. In Bladder Journal, the full diary, the Apple Watch app, reminders and PDF/CSV export are free; Audio Analysis is part of Bladder Journal PRO.
Does Bladderly charge for PDF export?
Yes. On Bladderly's free plan, each PDF export is a $1.99 one-time purchase; its paid plans, from a 3-day pass to annual subscriptions, include export (US App Store prices, September 2026). Bladder Journal's PDF and CSV export is free.
Do either of these apps work with Apple Watch?
Of the two, only Bladder Journal has an Apple Watch app. It lets you log urination events, start/stop the urination timer, record fluid intake, and note leakage directly from your wrist, and it works offline. Bladderly does not offer Apple Watch support.
Which app is better for privacy?
Bladder Journal, by a wide margin for anything involving sound. Its Audio Analysis runs entirely on the iPhone, and its privacy policy states that no audio recordings are ever stored or transmitted to any server. Bladderly records the sound in the app and calculates the volume once your phone is online. Its privacy policy lists "audio data limited to urination sounds" as sensitive information, names Amazon Web Services and Google Cloud Platform among the services it may share personal information with, and says data may be processed in the United States, South Korea and other countries. Bladder Journal also keeps your diary on your device by default, with optional iCloud sync and App Lock.
Does Bladderly work offline?
Only partly. Its help center says you can record without an internet connection, but the volume is calculated only once your device is connected, because the recording is processed online. Bladder Journal's Audio Analysis runs on the iPhone, so it gives you the volume without a connection.
Is Bladderly available on Android?
Yes, Bladderly is available on both iOS and Android, which is one of its advantages. Bladder Journal is currently iOS only (iPhone + Apple Watch). If you are on Android and want volume estimated from sound, Bladderly is the option.
Which has better audio analysis — Bladder Journal or Bladderly?
Both estimate the volume of each void from the sound of urination, so you can skip the measuring cup. The difference is where the audio goes. Bladder Journal's Audio Analysis analyses it on your iPhone in real time and discards it, and it works without an internet connection. Bladderly stores the recording in the app until you are online and then calculates the volume on its servers. Bladderly advertises "96% accuracy", a figure its published study does not report.
Which app has better AI features?
Bladder Journal, by a distance. Its PRO plans include Deep Insights (AI summaries of the patterns and triggers in your diary, with an exclusive Bubble Heatmap), Smart Alerts that predict bathroom timing and flag safe windows and dehydration risk, and AI Chat for questions about your own data. Bladderly's AI is its sound-based volume estimate; its App Store listing describes insights as a possible future feature.
Related Comparisons
Try Bladder Journal Free
All core tracking is free, including the Apple Watch app and the PDF report for your doctor. Audio Analysis and Deep Insights start at $5.99/month, with audio processed on your iPhone.
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