What this guide covers
A numeric rule begins with OCR and then parses a number from the recognized text. The first number in the selected region is the one used by the condition. This matters when a card displays a product identifier, a date and a price together. Crop to the intended value instead of expecting the rule to understand the semantic role of every number.
Set it up
Choose the number detector, isolate one value and select number changed, greater than or less than. Enter a plain numeric threshold for a comparison and select the desired action. To test a below-100 rule, show a clearly readable value above 100, then a value below 100. Finally show another nonmatching value and inspect the stored execution results.
Check the result
Greater than and less than are strict comparisons: equality does not satisfy either condition. Number changed uses a previous valid reading as a baseline, so the first recognized number does not by itself count as a numeric change. A blank frame or unreadable value is not a zero. Make these cases part of your test before depending on the rule.
Before you rely on it
Text normalization and numeric extraction do not establish a financial price feed or a measurement instrument. Commas used for thousands and decimal points deserve special attention, especially in sources that use a decimal comma. Compare the parsed number in history with the original screen. Do not assume that the website’s language automatically changes the numeric parser’s conventions.
Troubleshooting
An unexpected alert can come from OCR mistaking a character, a second number entering the region or a layout shift after zooming. A missing alert may be an unchanged reading, a comparison that never became true or a notification action that failed after recognition. Inspect the parsed value first, then the rule state, then delivery.
Product reference
Threshold conditions avoid repeatedly alerting while the same matching state persists; returning to a nonmatching state and crossing again is a different event. Restarting a source or editing a task can change its baseline. Re-test after such changes. Use screen alerts as assistance, not as the only safeguard for trading, medical equipment or other high-stakes decisions.
Yes. Select a region containing one number, then choose number changed, greater than or less than. For example, get an alert when stock falls below 10 or a price falls below 100. Number changed uses the first reading as its baseline. Each region reads its first number, so avoid including unrelated values. Speed and accuracy depend on image clarity, fonts and your device.
Further reading
- Color changes and reference-image matching
- Keep, review and export local recognition history
- Screen sharing and browser permissions