[{"data":1,"prerenderedAt":174},["ShallowReactive",2],{"product-detail:en:apple-watch-series-4":3},{"id":4,"name":5,"familyId":6,"branchId":7,"announcedAt":8,"year":9,"narrativeWeight":10,"signature":11,"predecessorId":12,"positioningReferenceIds":13,"architecturalAncestorIds":14,"peerIds":15,"technologyIds":16,"deltas":19,"technologies":138,"sourceRefs":145,"specVariants":146,"specs":150,"specSource":169},"apple-watch-series-4","Apple Watch Series 4","apple-watch","series","2018-09-12",2018,"epic","A major industrial redesign introduces 40mm\u002F44mm curved LTPO displays, the 64-bit S4 SiP, Fall Detection, and the first consumer-grade over-the-counter ECG sensor cleared by the US FDA.","apple-watch-series-3",[],[],[],[17,18],"digital-crown","retina-display",[20,31,36,42,48,55,61,66,71,77,82,87,93,99,104,110,116,122,128,133],{"id":21,"baselineProductId":12,"type":22,"category":23,"headline":24,"summary":25,"significance":26,"sourceRefs":27},"apple-watch-series-4-40mm-and-44mm-casing-architecture-with-curved-borders","introduced","display","40mm and 44mm casing architecture with curved borders","First physical case enlargement in Apple Watch history, expanding screen viewable area by over 30% while slimming overall case thickness from 11.4mm to 10.7mm; display corners are curved to match the contours of the casing.","defining",[28,29,30],"src-apple-watch-redesigned-apple-watch-series-4-revolutionizes-communication-fitness-and","src-apple-watch-ecg-app-and-irregular-heart-rhythm-notification-available-today-on-apple","src-apple-watch-sp778",{"id":32,"baselineProductId":12,"type":22,"category":23,"headline":33,"summary":34,"significance":26,"sourceRefs":35},"apple-watch-series-4-ltpo-oled-retina-display-backplane","LTPO OLED Retina display backplane","Low-Temperature Polycrystalline Oxide technology significantly improves display energy efficiency, permitting larger screen dimensions while preserving 18-hour battery longevity.",[28,29,30],{"id":37,"baselineProductId":12,"type":22,"category":38,"headline":39,"summary":40,"significance":26,"sourceRefs":41},"apple-watch-series-4-electrical-heart-sensor-hardware-digital-crown-and-bac","silicon","Electrical heart sensor hardware (Digital Crown & back crystal electrodes)","Physical electrodes integrated into the titanium Digital Crown and an ultrathin chromium silicon carbon nitride layer on the back sapphire crystal, forming a closed Lead I bi-potential circuit when a finger touches the crown.",[28,29,30],{"id":43,"baselineProductId":12,"type":22,"category":44,"headline":45,"summary":46,"significance":26,"sourceRefs":47},"apple-watch-series-4-consumer-ecg-app-fda-de-novo-class-ii-software-enablem","sensors","Consumer ECG app (FDA De Novo Class II software enablement)","Software application utilizing the built-in electrical heart sensor to record a 30-second electrocardiogram and classify normal sinus rhythm vs. Atrial Fibrillation (AFib). (Hardware present at launch on 2018-09-21; US software clearance granted 2018-09-11 via De Novo DEN180044; app launched via watchOS 5.1.2 on 2018-12-06; international rollout occurred iteratively across 2019–2021 as local regulatory approvals were secured).",[28,29,30],{"id":49,"baselineProductId":12,"type":22,"category":50,"headline":51,"summary":52,"significance":53,"sourceRefs":54},"apple-watch-series-4-fall-detection-capability","software","Fall Detection capability","Next-generation accelerometer and gyroscope sampling at 8x faster rates up to 32 g-forces; analyzes wrist trajectory and impact dynamics to detect hard falls and automatically call emergency services if the user remains immobile for 60 seconds.","meaningful",[28,29,30],{"id":56,"baselineProductId":12,"type":22,"category":57,"headline":58,"summary":59,"significance":53,"sourceRefs":60},"apple-watch-series-4-digital-crown-with-haptic-feedback","input","Digital Crown with haptic feedback","Completely re-engineered crown mechanism containing 21% more parts that incorporates precise tactile clicking sensations generated via the Taptic Engine.",[28,29,30],{"id":62,"baselineProductId":12,"type":22,"category":38,"headline":63,"summary":64,"significance":53,"sourceRefs":65},"apple-watch-series-4-apple-s4-64-bit-dual-core-sip","Apple S4 64-bit dual-core SiP","First custom 64-bit dual-core processor in an Apple Watch, delivering up to 2x faster application performance.",[28,29,30],{"id":67,"baselineProductId":12,"type":22,"category":38,"headline":68,"summary":69,"significance":53,"sourceRefs":70},"apple-watch-series-4-apple-w3-wireless-chip","Apple W3 wireless chip","(minor): Upgrades Bluetooth from 4.2 to Bluetooth 5.0 for improved wireless throughput and range.",[28,29,30],{"id":72,"baselineProductId":12,"type":22,"category":73,"headline":74,"summary":75,"significance":53,"sourceRefs":76},"apple-watch-series-4-universal-ceramic-and-sapphire-back-crystal","connectivity","Universal ceramic and sapphire back crystal","Black ceramic and sapphire back crystal becomes standard across all models (both GPS and GPS + Cellular), enhancing optical and electrical conductivity and radio wave transmission.",[28,29,30],{"id":78,"baselineProductId":12,"type":22,"category":57,"headline":79,"summary":80,"significance":53,"sourceRefs":81},"apple-watch-series-4-acoustic-redesign-50-louder-speaker-and-relocated-mic","Acoustic redesign (50% louder speaker & relocated mic)","Speaker volume increased by 50% for clearer phone calls, Walkie-Talkie, and Siri; microphone moved to the right side between the Digital Crown and Side button to eliminate acoustic feedback and echo.",[28,29,30],{"id":83,"baselineProductId":12,"type":22,"category":23,"headline":84,"summary":85,"significance":53,"sourceRefs":86},"apple-watch-series-4-infograph-and-infograph-modular-watch-faces","Infograph and Infograph Modular watch faces","(minor): Ultra-dense watch faces supporting up to eight complications, designed specifically for the expansive curved display corners.",[28,29,30],{"id":88,"baselineProductId":12,"type":22,"category":89,"headline":90,"summary":91,"significance":53,"sourceRefs":92},"apple-watch-series-4-gold-stainless-steel-casing-finish","product","Gold stainless steel casing finish","(minor): High-polish gold PVD stainless steel finish joins space black and silver.",[28,29,30],{"id":94,"baselineProductId":12,"type":95,"category":44,"headline":96,"summary":97,"significance":53,"sourceRefs":98},"apple-watch-series-4-optical-heart-sensor","changed","Optical heart sensor","Replaced four-diode cluster with a compact second-generation optical heart sensor; added low heart rate alerts (in addition to high heart rate) and irregular rhythm notifications (FDA De Novo clearance DEN180043 enabled in watchOS 5.1.2).",[28,29,30],{"id":100,"baselineProductId":12,"type":95,"category":73,"headline":101,"summary":102,"significance":53,"sourceRefs":103},"apple-watch-series-4-standardized-internal-storage","Standardized internal storage","16GB internal storage standardized across both GPS and GPS + Cellular configurations.",[28,29,30],{"id":105,"baselineProductId":12,"type":95,"category":106,"headline":107,"summary":108,"significance":53,"sourceRefs":109},"apple-watch-series-4-enclosure-thickness","design","Enclosure thickness","Reduced from 11.4mm to 10.7mm (-0.7mm), making Series 4 noticeably sleeker on the wrist.",[28,29,30],{"id":111,"baselineProductId":12,"type":112,"category":106,"headline":113,"summary":114,"significance":53,"sourceRefs":115},"apple-watch-series-4-38mm-and-42mm-original-case-standards","retired","38mm and 42mm original case standards","Retired from frontline production in favor of 40mm and 44mm form factors.",[28,29,30],{"id":117,"baselineProductId":12,"type":112,"category":118,"headline":119,"summary":120,"significance":53,"sourceRefs":121},"apple-watch-series-4-ceramic-edition-tier","storage","Ceramic Edition tier","(minor): White and gray ceramic Edition models omitted during the Series 4 generation (returning later in Series 5).",[28,29,30],{"id":123,"baselineProductId":12,"type":124,"category":89,"headline":125,"summary":126,"significance":53,"sourceRefs":127},"apple-watch-series-4-backwards-band-compatibility","retained","Backwards band compatibility","Retained complete compatibility with older bands (40mm accepts 38mm bands; 44mm accepts 42mm bands).",[28,29,30],{"id":129,"baselineProductId":12,"type":124,"category":89,"headline":130,"summary":131,"significance":53,"sourceRefs":132},"apple-watch-series-4-50-meter-water-resistance-iso-22810-2010","50-meter water resistance (ISO 22810:2010)","Maintained swimproof rating with acoustic water ejection.",[28,29,30],{"id":134,"baselineProductId":12,"type":124,"category":23,"headline":135,"summary":136,"significance":53,"sourceRefs":137},"apple-watch-series-4-18-hour-all-day-battery-life-standard","18-hour all-day battery life standard","Maintained 18-hour daily target despite 30%+ larger screen and more powerful 64-bit architecture.",[28,29,30],[139,142],{"id":17,"name":140,"category":57,"description":141},"Digital Crown","Rotary navigation control introduced on Apple Watch.",{"id":18,"name":143,"category":23,"description":144},"Retina display","High-density display branding introduced on iPhone 4 and later expanded across product families.",[28,29,30],[147],{"id":148,"label":149,"specs":150,"source":164,"verificationSource":169},"apple-watch-s4","default",{"cpu":151,"cores":152,"memory":153,"storage":154,"display":155,"gpu":156,"ports":157,"weight":158,"dimensions":159,"operatingSystem":160,"released":161,"discontinued":162,"launchPrice":163},"Apple S4 (64-bit dual-core) · 1 GHz","2","1 GB","16 GB","1.78\" LTPO OLED, 448×368","Integrated","Magnetic inductive charging","~36 g","40 mm or 44 mm case","watchOS 5","September 21, 2018","September 2019","$399",{"name":165,"url":166,"retrievedAt":167,"note":168},"One Infinite Fruit","https:\u002F\u002Foneinfinitefruit.com\u002Fdevice\u002Fapple-watch-s4\u002F","2026-09-14","secondary-structured-specs",{"name":170,"url":171,"retrievedAt":172,"note":173},"Apple Watch Series 4 - Technical Specifications","https:\u002F\u002Fsupport.apple.com\u002Fkb\u002FSP778","2026-09-13","first-party-verification",1789955608574]