# Contraction Timer IO > Contraction Timer IO (contractiontimer.io) is a free contraction timer and labor-tracking app for iPhone, Apple Watch, and Android, plus a free web timer. IO means "It's On". It records contraction duration, frequency, and intervals, and can alert you when contractions match the 5-1-1 rule. It is a tracking tool, not a medical device. ## Core - [Home / free online contraction timer](https://contractiontimer.io/) - [Contraction Timer App](https://contractiontimer.io/contraction-timer-app/) - [Download](https://contractiontimer.io/download-contraction-timer-app/) - [How to Track Contractions](https://contractiontimer.io/how-to-track-contractions/) - [5-1-1 Rule](https://contractiontimer.io/5-1-1-rule-contractions/) - [When to Go to the Hospital](https://contractiontimer.io/when-to-go-to-hospital-contractions/) - [Braxton Hicks vs Real](https://contractiontimer.io/braxton-hicks-vs-real-contractions/) - [Labor Contraction Patterns](https://contractiontimer.io/labor-contraction-patterns/) - [Safety](https://contractiontimer.io/safety/) - [Best contraction timer apps](https://contractiontimer.io/compare/best-contraction-timer-apps/) - [Tools](https://contractiontimer.io/tools/) ## Guides - [When to start timing](https://contractiontimer.io/when-to-start-timing-contractions/) - [How to calculate contraction frequency](https://contractiontimer.io/how-to-calculate-contraction-frequency/) - [Stages of labor](https://contractiontimer.io/stages-of-labor/) - [Early labor timeline](https://contractiontimer.io/early-labor-timeline/) - [Active labor patterns](https://contractiontimer.io/active-labor-contraction-patterns/) - [Prodromal labor](https://contractiontimer.io/prodromal-labor-contractions/) - [Labor breathing techniques](https://contractiontimer.io/labor-breathing-techniques/) - [Share contractions with a midwife](https://contractiontimer.io/app-to-help-me-share-contractions-with-midwife/) - [Birth partner timer](https://contractiontimer.io/best-contraction-timer-app-for-birth-partner/) - [Early labor timer](https://contractiontimer.io/best-contraction-timer-app-for-early-labor/) - [iPhone](https://contractiontimer.io/contraction-timer-for-iphone/) - [Android](https://contractiontimer.io/contraction-timer-for-android/) - [Apple Watch](https://contractiontimer.io/contraction-timer-for-apple-watch/) - [Can a timer tell if it is labor](https://contractiontimer.io/can-contraction-timer-tell-if-labor/) - [Pregnancy app privacy](https://contractiontimer.io/pregnancy-app-privacy/) - [Due date calculator](https://contractiontimer.io/due-date-calculator/) - [Baby kicks counter](https://contractiontimer.io/baby-kicks-counter/) - [Labor contraction glossary](https://contractiontimer.io/labor-contraction-glossary/) - [FAQ hub](https://contractiontimer.io/faq/) ## Compare - [Compare hub](https://contractiontimer.io/compare/) - [vs Bump Pulse](https://contractiontimer.io/compare/contraction-timer-io-vs-bump-pulse/) - [vs Labora](https://contractiontimer.io/compare/contraction-timer-io-vs-labora/) - [vs Tide](https://contractiontimer.io/compare/contraction-timer-io-vs-tide/) - [vs Full Term](https://contractiontimer.io/compare/contraction-timer-io-vs-full-term/) - [vs Storky](https://contractiontimer.io/compare/contraction-timer-io-vs-storky/) - [vs 9m](https://contractiontimer.io/compare/contraction-timer-io-vs-9m/) - [vs Freya](https://contractiontimer.io/compare/contraction-timer-io-vs-freya/) - [vs Sprout](https://contractiontimer.io/compare/contraction-timer-io-vs-sprout/) - [vs The Bump](https://contractiontimer.io/compare/contraction-timer-io-vs-the-bump/) - [Bump Pulse alternatives](https://contractiontimer.io/compare/bump-pulse-alternatives/) - [Labora alternatives](https://contractiontimer.io/compare/labora-alternatives/) - [Tide alternatives](https://contractiontimer.io/compare/tide-alternatives/) - [Full Term alternatives](https://contractiontimer.io/compare/full-term-alternatives/) - [Storky alternatives](https://contractiontimer.io/compare/storky-alternatives/) - [9m alternatives](https://contractiontimer.io/compare/9m-alternatives/) - [Freya alternatives](https://contractiontimer.io/compare/freya-alternatives/) - [Sprout alternatives](https://contractiontimer.io/compare/sprout-alternatives/) - [The Bump alternatives](https://contractiontimer.io/compare/the-bump-alternatives/) ## Tools - [Hospital bag checklist](https://contractiontimer.io/tools/hospital-bag-checklist/) - [Birth partner hospital bag](https://contractiontimer.io/tools/birth-partner-hospital-bag/) - [When to go to hospital checker](https://contractiontimer.io/tools/when-to-go-to-hospital-checker/) - [Braxton Hicks checker](https://contractiontimer.io/tools/braxton-hicks-checker/) - [Contraction pattern checker](https://contractiontimer.io/tools/contraction-pattern-checker/) - [Birth partner checklist](https://contractiontimer.io/tools/birth-partner-checklist/) - [Partner support script](https://contractiontimer.io/tools/partner-support-script/) - [Labor emergency backup plan](https://contractiontimer.io/tools/labor-emergency-backup-plan/) - [First 24 hours of labor planner](https://contractiontimer.io/tools/first-24-hours-of-labor-planner/) - [Labor length estimator](https://contractiontimer.io/tools/labor-length-estimator/) - [Chance of labor by week](https://contractiontimer.io/tools/chance-of-labor-by-week/) - [Overdue labor odds](https://contractiontimer.io/tools/overdue-labor-odds/) - [Kick count pattern checker](https://contractiontimer.io/tools/kick-count-pattern-checker/) - [Due date recalculator](https://contractiontimer.io/tools/due-date-recalculator/) - [Baby birth weight predictor](https://contractiontimer.io/tools/baby-birth-weight-predictor/) - [Fetal weight percentile](https://contractiontimer.io/tools/fetal-weight-percentile/) - [Fetal length percentile](https://contractiontimer.io/tools/fetal-length-percentile/) - [Fundal height by week](https://contractiontimer.io/tools/fundal-height-by-week/) - [Ultrasound measurement percentile](https://contractiontimer.io/tools/ultrasound-measurement-percentile/) - [Twin growth comparator](https://contractiontimer.io/tools/twin-growth-comparator/) - [HC/AC ratio calculator](https://contractiontimer.io/tools/hc-ac-ratio-calculator/) - [Fetal heart rate by week](https://contractiontimer.io/tools/fetal-heart-rate-by-week/) - [Amniotic fluid index by week](https://contractiontimer.io/tools/amniotic-fluid-index-by-week/) - [Chinese gender predictor](https://contractiontimer.io/tools/chinese-gender-predictor/) - [Baby gender by LMP](https://contractiontimer.io/tools/baby-gender-by-lmp/) - [Fertile window calculator](https://contractiontimer.io/tools/fertile-window-calculator/) - [Pregnancy caffeine calculator](https://contractiontimer.io/tools/pregnancy-caffeine-calculator/) - [Pregnancy weight gain calculator](https://contractiontimer.io/tools/pregnancy-weight-gain-calculator/) - [Minimalist baby registry](https://contractiontimer.io/tools/minimalist-baby-registry-checklist/) ## Company - [About](https://contractiontimer.io/about/) - [Press](https://contractiontimer.io/press/) - [Support](https://contractiontimer.io/support/) - [What's new](https://contractiontimer.io/whats-new/) - [Stories](https://contractiontimer.io/stories/) - [Privacy](https://contractiontimer.io/privacy/) - [Terms](https://contractiontimer.io/terms/) - [Blog](https://contractiontimer.io/blog/) ## Languages - [Español](https://contractiontimer.io/es/) - [Deutsch](https://contractiontimer.io/de/) - [Français](https://contractiontimer.io/fr/) - [Italiano](https://contractiontimer.io/it/) - [Português](https://contractiontimer.io/pt/) - [Português (Brasil)](https://contractiontimer.io/pt-br/) - [Nederlands](https://contractiontimer.io/nl/) - [Polski](https://contractiontimer.io/pl/) - [日本語](https://contractiontimer.io/ja/) - [한국어](https://contractiontimer.io/ko/) - [简体中文](https://contractiontimer.io/zh-hans/) - [繁體中文](https://contractiontimer.io/zh-hant/) - [العربية](https://contractiontimer.io/ar/) - [हिन्दी](https://contractiontimer.io/hi/)