Heart rate guides and product methodology

Choose a guide by your goal

What these guides do differently

The methodology article refers to the actual behavior of this codebase: user-generated tap timestamps, millisecond intervals, short rolling windows and local browser history. It does not imply that the browser can sense a heartbeat. Health reference ranges are kept separate from the product calculation and linked to their original authoritative sources.

Every result still depends on your ability to find a pulse and tap with each beat. If a pulse feels irregular, a value is surprising, or symptoms are present, a tap estimator is the wrong tool for deciding what is happening.

How to use a result responsibly

Start by labeling the situation: a calm resting check and a reading taken after activity are not interchangeable. Repeat an unexpected value under the same conditions and note whether a tap was missed or added. The browser's recent-history chart is a convenience for comparison, not an alert system and not a clinical record.

A BPM estimate cannot identify a rhythm problem or explain a change. Symptoms and personal medical context take priority over a general range. If a suddenly unusual heart rate comes with chest pain, shortness of breath, fainting or marked dizziness, contact local emergency services instead of repeating the calculator.

How the library is maintained

Guides show publication and review dates, distinguish editorial review from medical review, and link health claims to named sources. Product statements are checked against the current code. If a source changes or a feature behaves differently, the relevant page should be corrected rather than duplicated in another guide. The full process and correction contact are on the About page.