Autonomous Systems (AS) in Japan

AS numbers assigned in Japan (JP), ranked by the number of IPv4 addresses mapped to each AS. Organization names are shown as registered.

Data as of: 2026-10-19

RankAS numberOrganizationIPv4 addresses
1 AS17676 SoftBank Corp. 38,445,056
2 AS4713 NTT DOCOMO BUSINESS,Inc. 28,624,384
3 AS2516 KDDI CORPORATION 18,072,575
4 AS2907 Research Organization of Information and Systems, National Institute of Informatics 8,769,536
5 AS17506 ARTERIA Networks Corporation 5,382,144
6 AS9824 JCOM Co., Ltd. 4,745,214
7 AS2497 Internet Initiative Japan Inc. 4,093,184
8 AS2527 Sony Network Communications Inc. 3,867,648
9 AS2518 BIGLOBE Inc. 3,670,016
10 AS17511 OPTAGE Inc. 2,994,432
11 AS9605 NTT DOCOMO, INC. 2,536,448
12 AS2514 NTT PC Communications, Inc. 2,078,976
13 AS10013 FreeBit Co.,Ltd. 1,944,064
14 AS4725 SoftBank Corp. 1,918,720
15 AS9595 NTT-ME Corporation 1,513,472
16 AS18126 Chubu Telecommunications Company, Inc. 1,505,536
17 AS10010 TOKAI Communications Corporation 1,501,184
18 AS2510 FUJITSU LIMITED 1,487,616
19 AS2519 ARTERIA Networks Corporation 1,464,320
20 AS4685 Asahi Net 1,277,952
21 AS9617 JCOM Co., Ltd. 1,163,264
22 AS4694 IDC Frontier Inc. 1,040,896
23 AS7679 QTnet,Inc. 760,832
24 AS4721 JCOM Co., Ltd. 631,808
25 AS7522 STNet, Incorporated 594,944
26 AS7671 NTT SmartConnect Corporation 453,888
27 AS18081 Kintetsu Cable Network Co., Ltd. 442,368
28 AS138384 Rakuten Mobile Network, Inc. 420,864
29 AS9365 its communications Inc. 404,480
30 AS18071 Panasonic Information Systems Co., Ltd 383,232
31 AS7684 SAKURA Internet Inc. 368,640
32 AS7524 ITEC HANKYU HANSHIN CO.,LTD. 366,336
33 AS9370 SAKURA Internet Inc. 340,992
34 AS131932 JR East Information Systems Company 327,680
35 AS9371 SAKURA Internet Inc. 297,216
36 AS18144 Enecom,Inc. 291,840
37 AS9597 KDDI Web Communications Inc. 276,736
38 AS7506 GMO Internet, Inc. 252,672
39 AS9351 ZTV CO.,LTD 249,856
40 AS4673 NTT DATA CORPORATION 241,664
41 AS2522 Japan Network Information Center 229,120
42 AS2506 NTT business Solutions corporation 214,272
43 AS7687 TOYOTA SYSTEMS CORPORATION 200,960
44 AS2501 The University of Tokyo 200,704
45 AS9354 Community Network Center Inc. 200,448
46 AS23793 National Institute of Advanced Industrial Science and Technology 199,936
47 AS9619 Sony Global Solutions Inc. 199,680
48 AS4686 BEKKOAME INTERNET INC. 198,400
49 AS7514 Computer Engineering & Consulting, Ltd. 192,000
50 AS17698 COMMUNITY NETWORK CENTER INCORPORATED. 174,080
51 AS9374 EDION Corporation 165,888
52 AS9614 JCOM Marketing Co.,Ltd. 165,888
53 AS131965 Xserver Inc. 165,120
54 AS9997 Suzuka Cable Co.,Ltd 157,696
55 AS10006 SECOM Trust Systems Co.,Ltd. 146,176
56 AS18077 Yamaguchi Cable Vision Co.,Ltd 135,680
57 AS17529 STARCAT Co .,LTD. 135,424
58 AS7670 Enecom,Inc. 134,656
59 AS2504 Kyoto University 132,096
60 AS37917 University of Tsukuba 132,096
61 AS7509 Hokkaido University 131,328
62 AS17687 National University Corporation Nagoya University 131,328
63 AS4729 Japan Atomic Energy Agency 131,072
64 AS9355 National Institute of Information and Communications Technology 131,072
65 AS38635 Keio University 131,072
66 AS63802 Nippon Telegraph and Telephone East Corporation 131,072
67 AS7516 TOHKnet Co.,Inc. 119,040
68 AS24572 Yahoo Japan 118,784
69 AS3488 Japan Aerospace Exploration Agency 115,200
70 AS10021 KVH Co.,Ltd 110,848
71 AS38631 LY Corporation 108,288
72 AS59108 KATCH NETWORK INC. 96,256
73 AS17534 NSK Co.,Ltd. 94,208
74 AS131921 GMO GlobalSign Holdings K.K. 92,928
75 AS17707 AS for DATAHOTEL, which is one of iDC in Japan, 90,368
76 AS4678 Canon IT Solutions Inc. 90,112
77 AS9993 ITOCHU Techno-Solutions Corporation 89,088
78 AS24282 KAGOYA JAPAN Inc. 89,088
79 AS58791 GMO Internet, Inc. 86,784
80 AS17514 Otsuka Corp. 83,968
81 AS9600 So-net Corporation 82,944
82 AS9466 UUNET Japan Limited 82,688
83 AS7511 SYNAPSE Co.,Ltd. 78,848
84 AS9622 Kurashiki Cable TV 78,848
85 AS18260 EHIME CATV CO.,LTD. 78,592
86 AS38628 HIMEJI CABLE TELEVISION CORPORATION 77,824
87 AS9621 Okinawa Telecommunication Network Co.,Inc 76,800
88 AS2505 High Energy Accelerator Research Organization, KEK 74,240
89 AS55374 FUJITSU LIMITED 74,240
90 AS10000 Nagasaki Cable Media Inc. 73,728
91 AS58647 Kagawa University 73,728
92 AS23781 Toyama University 72,704
93 AS9615 TOYOHASHI CABLE NETWORK INC. 71,680
94 AS17939 miyazaki cabletelevision network Co.,LTD 71,680
95 AS7502 Advanced Software Technology & Management Research Institute of KYOTO 70,144
96 AS17947 SAKURA KCS Corporation. 69,632
97 AS18271 Sojitz Tech Innovation Co., Ltd. 69,632
98 AS23820 Rakuten Group, Inc. 69,632
99 AS37918 NTT, Inc. 69,376
100 AS7672 Hokuden Information System Service Co.,Ltd. 68,352

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