The is a commuter and suburban electric multiple unit (EMU) train type developed by East Japan Railway Company (JR East) from the earlier E231 series and the E531 series design. The first train was introduced in December 2006 for use on the Chūō Line (Rapid), followed by the E233-1000 series variant in 2007 for use on the Keihin–Tōhoku and Negishi lines, the E233-3000 series outer-suburban variant in December 2007 for use on the Tōkaidō Main Line, and narrow-bodied E233-2000 series variant for Jōban Line and Tokyo Metro Chiyoda Line through services. Further variants were built for use on the Keiyō Line, Yokohama Line, Saikyō Line, and Nambu Line.

Design The E233 series features two identical sets of main equipment in case of failure. This is the first JR East stock to feature such backup measures. The E233 series provides for better accessibility for the disabled, and is designed to be more comfortable to ride overall than previous stock. The height between the platform and the train was reduced from the of the 201 and 209 series to only . Seats are wide, compared to the of the 201 series and of the 209 series. For standing passengers the handle straps have been lowered by compared to older train models.

This stock also features an air filtration system to remove unpleasant smells. It also features liquid crystal display information screens and automatic announcement system similar to those previously used on the E231 series rolling stock on the Yamanote Line.

The stock is the first JR East stock to use full-colour LEDs for the destination indicators on the sides of the carriages. This is due to the fact that the Chūō Line has numerous types of services, and colour-coding will help passengers board the correct train.

Variants E233-0 series: 4-, 6-, and 10-car sets used on the Chūō Rapid, Ōme, Itsukaichi, Hachikō and Fujikyuko lines since 26 December 2006. E233-1000 series: 10-car sets used on the Keihin–Tōhoku and Negishi lines since 22 December 2007, on the Keiyō Line since 7 May 2026. E233-2000 series: 10-car sets used on Jōban Line/Tokyo Metro Chiyoda Line through services since 9 September 2009 E233-3000 series: 5- and 10-car sets used on Tōkaidō Main Line, Takasaki Line, and Utsunomiya Line outer-suburban services since March 2008, and on Ueno–Tokyo Line and Shōnan–Shinjuku Line through services since March 2015 E233-5000 series: 4-, 6-, and 10-car sets used on the Keiyō Line since 1 July 2010 E233-6000 series: 8-car sets used on the Yokohama Line since 16 February 2014 E233-7000 series: 10-car sets used on the Saikyō Line, Kawagoe Line and Rinkai Line since 30 June 2013, and on Sōtetsu Shin-Yokohama Line and Sōtetsu Main Line services since November 2019 E233-8000 series: 6-car sets used on the Nambu Line since 4 October 2014 E233-8500 series: One converted former E233-0 series 6-car set used on the Nambu Line from 2017

E233-0 series

The first E233-0 series train was introduced in December 2006 for use on the Chūō Line (Rapid), Ōme, and Itsukaichi lines, replacing the aging 201 series trains. The fleet of 688 E233-0 series vehicles (10-car x 42, 6-car x 28, 4-car x 25) was delivered by the end of March 2008;"Tetsudō Daiya Jōhō" magazine May 2008 issue, p. 53 (in Japanese) 42 ten-car sets (T1-T42), and 15 6+4-car sets (H43-H57) were constructed primarily for use on the Chūō Line (but also on through services to the Ōme, Itsukaichi, Hachikō, and Fujikyuko Lines), while ten four-car sets (Ao458-Ao467) and 13 six-car sets (Ao658-Ao670) were constructed for the Ōme Line and Itsukaichi Line. In March 2008 and April 2015, sets Ao458+Ao658 and Ao459+Ao659 were transferred to the Chūō Line and renumbered H58 and H59 respectively.

An additional five cars were built at JR East's Niitsu factory in 2009 to replace five cars from six-car set Ao661 which were withdrawn due to accident damage in 2008.

Green Car introduction In April 2018, JR East announced plans to add two bilevel Green (first class) cars to 58 ten-car and six-car E233-0 series EMU sets operated on the Chūō Line and through-service trains to the Ōme Line, and to install toilets on these sets ahead of Green car introductions. To compensate for train shortages brought on by toilet installations, a new ten-car set (T71) was delivered from J-TREC's Yokohama facility on 11 June 2020.

The Green cars will be positioned as cars 4 and 5 in the newly formed 12- and 8-car sets. Green car services were initially due for introduction in fiscal 2020, but this was deferred to 2023. On 27 April 2022, JR East announced that Green car introductions would again be postponed until the end of fiscal 2024 or later as a result of the global chip shortage.

The first Green cars, SaRo E233-1 and SaRo E232-1, were delivered from J-TREC's Yokohama facility from 12 July 2022. These cars use double-leaf sliding doors with a width of to allow for reduced boarding times at stations; previous designs were built using single-leaf doors with a width of . Test runs of the new Green cars were conducted, starting with set H57. The new Green cars were eventually put into service on a trial basis as of 13 October 2024.

Transfer In 2017, six-car set Ao670 was modified to become the E233-8500 series set N36 for use on the Nambu Line alongside the fleet of E233-8000 series sets.

In December 2025, ten-car set T71 was transferred to Makuhari Depot as a six-car set and renumbered C1. Six cars from set H49 followed suit in January 2026 and became set C3, while four cars from set H49 was renumbered as set C2, lengthened as six cars from former two cars of set T71. On 10 September 2026, JR East announced that the 6 car E233s will be rolled out in the Boso Area in October 2026.

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Formations

10-car Chūō Line sets As of 11 June 2020, 43 ten-car sets (T1-T42 and T71) are based at Toyoda Depot and formed with six motored ("M") cars and four non-powered trailer ("T") cars.

   Car No. 1 2 3 4 5 6 7 8 9 10Sets with on-board toilet Designation Tc M M' T M M' T M M' Tc' Numbering KuHa E233 MoHa E233 MoHa E232 SaHa E233-500 MoHa E233-200 MoHa E232-200 SaHa E233 MoHa E233-400 MoHa E232-400 KuHa E232 Capacity (total/seated) 142/39 160/54 155/48 160/54 142/39Sets without on-board toilet Designation Tc M M' M M' T M M' Tc' Numbering KuHa E233 MoHa E233 MoHa E232 MoHa E233-200 MoHa E232-200 SaHa E233-500 SaHa E233 MoHa E233-400 MoHa E232-400 KuHa E232 Capacity (total/seated) 142/39 160/54 142/39 MoHa E233-200 and MoHa E233-400 cars each have one PS33D single-arm pantograph, and MoHa E233 cars has two PS33D single-arm pantographs (one used as a backup). Cars 1 and 10 have a wheelchair space (also car 4 in sets equipped with a toilet). Car 4 has a universal design toilet (in sets equipped with a toilet). Car 4 is designated as a mildly air-conditioned car.

6+4-car Chūō Line sets As of 22 March 2020, 17 6+4-car sets (H43-H59) are based at Toyoda Depot and formed with six motored ("M") cars and four non-powered trailer ("T") cars.

   Car No. 1 2 3 4 5 6 7 8 9 10Sets with on-board toilet Designation Tc M M' M M' Tc' Tc M M' Tc' Numbering KuHa E233 MoHa E233 MoHa E232 MoHa E233-800 MoHa E232-200 KuHa E232-500 KuHa E233-500 MoHa E233-600 MoHa E232-600 KuHa E232 Capacity (total/seated) 142/39 160/54 155/48 160/54 142/42 142/42 160/54 142/39Sets without on-board toilet Designation Tc M M' M M' Tc' Tc M M' Tc' Numbering KuHa E233 MoHa E233 MoHa E232 MoHa E233-200 MoHa E232-200 KuHa E232-500 KuHa E233-500 MoHa E233-600 MoHa E232-600 KuHa E232 Capacity (total/seated) 142/39 160/54 142/42 142/42 160/54 142/39 Car 4 has one PS33D single-arm pantograph, and cars 2 and 8 each have two PS33D single-arm pantographs (one used as a backup). Cars 1 and 10 have a wheelchair space (also car 4 in sets equipped with a toilet). Car 4 has a universal design toilet (in sets equipped with a toilet). Car 4 is designated as a mildly air-conditioned car.

6+4-car Ōme Line and Itsukaichi Line sets As of 1 October 2018, ten six-car sets (Ao660-Ao669) and eight four-car (Ao460-Ao467) sets are based at Toyoda Depot and formed with six motored ("M") cars and four non-powered trailer ("T") cars. Depending on the specific schedule and line, trains are operated in 4-, 6-, or 6+4-car sets.

   Car No. 1 2 3 4 5 6 7 8 9 10 Designation Tc M M' M M' Tc' Tc M M' Tc' Numbering KuHa E233 MoHa E233 MoHa E232 MoHa E233-200 MoHa E232-200 KuHa E232-500 KuHa E233-500 MoHa E233-600 MoHa E232-600 KuHa E232 Capacity (total/seated) 142/39 160/54 142/42 142/42 160/54 142/39 Car 4 has one PS33D single-arm pantograph, and cars 2 and 8 each have two PS33D single-arm pantographs (one used as a backup). Cars 1 and 10 have a wheelchair space. Car 4 is designated as a mildly air-conditioned car.

E233-1000 series

A fleet of 83 ten-car E233 series sets was introduced on the Keihin–Tōhoku and Negishi lines from autumn 2007, replacing the 209 series EMUs previously used from 1993 until 2010. The first set was delivered in August 2007. The main difference over the earlier E233-0 series is the absence of passenger door controls.

The first set entered service on 22 December 2007.

Two cars of set 177, KuHa E233-1077 and SaHa E233-1277, were involved in a derailment in February 2014 and were scrapped in December 2016. The remaining eight cars of set 177 were scrapped in April 2018.

Set 103 was transferred to the Keiyō Depot for use on the Keiyō, Uchibō and Sotobō lines in January 2026. That set began service on these services on 7 May 2026.

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Formation As of June 2026, 81 ten-car sets were based at Saitama depot and formed with six motored ("M") cars and four non-powered trailer ("T") cars.

   Car No. 10 9 8 7 6 5 4 3 2 1 Designation Tc T M M' T M M' M M' Tc' Numbering KuHa E233-1000 SaHa E233-1200 MoHa E233-1400 MoHa E232-1400 SaHa E233-1000 MoHa E233-1000 MoHa E232-1000 MoHa E233-1200 MoHa E232-1200 KuHa E232-1000

Set 103 has been reconfigured to resemble the -5000 series, and is based at Keiyō Depot and formed with six motored ("M") cars and four non-powered trailer ("T") cars.

   Car No. 10 9 8 7 6 5 4 3 2 1 Designation Tc M M' T T M M' M M' Tc' Numbering KuHa E233-1003 MoHa E233-1403 MoHa E232-1403 SaHa E233-1203 SaHa E233-1003 MoHa E233-1003 MoHa E232-1003 MoHa E233-1203 MoHa E232-1203 KuHa E232-1003

E233-2000 series

This is a narrow-bodied variant for Jōban Line and Tokyo Metro Chiyoda Line through services, replacing the 203 series and 207-900 series EMUs previously used."Japan Railfan Magazine" March 2008 issue, p. 73 (in Japanese) The first ten-car set was delivered to Matsudo Depot from Tokyu Car Corporation in May 2009. It entered service on 9 September 2009. These trains have also been used on through services on Odakyu lines since 2016. In 2017 the last set was delivered (set number 19 built by J-TREC). Like all trains running into the Tokyo Subway, these trains are fitted with emergency doors in the driver's cabin to allow for the evacuation of passengers in the Chiyoda Line's tunnels.

The floor height is lowered to for improved accessibility, compared to for the earlier 203 series and for the 207-900 series and 209-1000 series trains.

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Formation , the fleet consists of 19 ten-car sets, numbered 1 to 19, based at Matsudo Depot, and formed as shown below, with car 1 at the southern end.

   Car No. 10 9 8 7 6 5 4 3 2 1 Designation Tc M M' T M M' T M M' Tc' Numbering KuHa E233-2000 MoHa E233-2400 MoHa E232-2400 SaHa E233-2200 MoHa E233-2000 MoHa E232-2000 SaHa E233-2000 MoHa E233-2200 MoHa E232-2200 KuHa E232-2000

Cars 3 and 9 are equipped with one single-arm pantograph. Car 6 is equipped with two.

Build details The delivery dates for the fleet are as shown below.