| Date | IP Address |
| 2020-10-24 | 52.198.153.219 (ClassC) |
| 2023-12-17 | 52.192.87.235 (ClassC) |
| 2024-05-01 | 52.69.1.185 (ClassC) |
| 2024-07-10 | 54.250.141.29 (ClassC) |
| 2024-10-04 | 18.176.163.115 (ClassC) |
| 2024-12-23 | 54.64.148.222 (ClassC) |
| 2025-01-08 | 3.113.128.30 (ClassC) |
| 2025-05-09 | 52.197.176.62 (ClassC) |
| 2025-05-14 | 52.198.174.233 (ClassC) |
| 2025-06-27 | 13.114.198.211 (ClassC) |
| 2025-08-21 | 18.177.27.18 (ClassC) |
| 2025-09-11 | 13.230.188.111 (ClassC) |
| 2025-10-02 | 35.72.70.186 (ClassC) |
| 2025-10-10 | 54.248.69.20 (ClassC) |
| 2025-11-19 | 18.181.126.192 (ClassC) |
| Date | Domain | IP |
| abc011.contest.atcoder.jp | 2025-09-07 | 54.248.212.207 |
| ijpc2015-2.contest.atcoder.jp | 2023-12-17 | 35.74.49.246 |
| jag2014summer-day2.contest.atcoder.jp | 2023-12-19 | 18.178.198.236 |
| abc013.contest.atcoder.jp | 2025-09-07 | 18.179.245.43 |
| agc013.contest.atcoder.jp | 2024-01-08 | 52.197.192.28 |
| abc043.contest.atcoder.jp | 2023-12-17 | 52.192.87.235 |
| arc004.contest.atcoder.jp | 2024-10-11 | 54.249.159.122 |
| arc075.contest.atcoder.jp | 2023-12-17 | 52.192.87.235 |
| abc026.contest.atcoder.jp | 2025-09-07 | 57.181.78.215 |
| www.abc026.contest.atcoder.jp | 2025-08-27 | 54.95.52.236 |
| abc007.contest.atcoder.jp | 2025-08-27 | 35.74.137.7 |
| arc017.contest.atcoder.jp | 2024-10-11 | 54.249.159.122 |
| abc038.contest.atcoder.jp | 2024-01-07 | 52.198.66.14 |
| tenka1-2016-quala.contest.atcoder.jp | 2024-07-27 | 175.41.250.70 |
| practice.contest.atcoder.jp | 2024-01-09 | 52.193.3.14 |
| code-festival-2014-final-open.contest.atcoder.jp | 2024-01-10 | 52.193.3.14 |