| Cover | 9 Months Ended |
| Sep. 30, 2021 | |
| Cover [Abstract] | |
| Document Type | S-1/A |
| Amendment Flag | false |
| Entity Registrant Name | IIOT-OXYS, INC. |
| Entity Central Index Key | 0001290658 |
| Entity Filer Category | Non-accelerated Filer |
| Entity Small Business | true |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
