Frequently asked questions
Does SmartCalcu need an internet connection?
Handwriting recognition and calculation both run locally on your device, so no connection is needed —
it works in airplane mode. The only feature that may use the network is voice input, which calls the
speech recognition service built into your operating system; on some OS versions that service
requires a connection. Skip voice input and there is no network activity at all.
Do I need an account? Do you collect my data?
No account, and no personal information is collected. There is no user account system, no ad SDK and
no analytics tracking. See the Privacy Policy.
Are my handwritten formulas uploaded?
No. Your strokes are processed in device memory into input for the recognition model, then discarded.
Nothing is uploaded or retained.
Why does handwriting recognition sometimes get it wrong?
Recognition is a probabilistic model and is sensitive to legibility. A few tips:
- Write larger and leave gaps so characters do not touch
- Write near the baseline of the whiteboard
- Make easily confused characters distinct, e.g. 1 vs. 7, x vs. ×, dot vs. comma
Which operations are supported?
Addition, subtraction, multiplication and division, decimals, and brackets to control precedence —
for example
12×(3+4)÷2. Standard precedence applies: brackets first, then multiplication
and division, then addition and subtraction.
Why does it say the formula needs a check?
The current formula is not a valid expression. Common causes: unpaired brackets, consecutive
operators, a trailing operator, or division by zero. Fix it and the result appears automatically.
How does voice input work?
Tap the microphone button and speak, e.g. "twelve times three plus four". Speak clearly in a quiet
environment. First use requires microphone permission (plus speech recognition permission on
iOS / macOS). If you decline, voice input is unavailable but keypad and handwriting keep working.
How is the web version different from the app?
The core recognition and calculation are identical. The differences: the web version downloads the
recognition model on first visit (then the browser caches it), and it has no voice input.
Why is the first launch slow?
The app loads and initializes the local recognition model. This happens once at startup; after that
recognition is immediate. The web version also downloads the model file on first visit, which
depends on your connection speed.
Does it cost anything? Any ads or in-app purchases?
No in-app purchases, no subscriptions, no ads.
Can I rely on the results for homework or work?
SmartCalcu is an assistive tool and recognition can be wrong. Always verify results before using them
for homework, financial or engineering purposes. See the Terms of Service.
How do I report a bug or suggest a feature?
Email w2386767757@163.com with your device model, OS version
and the exact steps involved. We usually reply within 1–3 business days. See
Support for details.