| Cover | Oct. 31, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 31, 2024 |
| Entity File Number | 001-39387 |
| Entity Registrant Name | Renalytix plc |
| Entity Central Index Key | 0001811115 |
| Entity Tax Identification Number | 00-0000000 |
| Entity Incorporation, State or Country Code | X0 |
| Entity Address, Address Line One | 2 Leman Street |
| Entity Address, City or Town | London |
| Entity Address, Country | GB |
| Entity Address, Postal Zip Code | E1W 9US |
| Country Region | 44 |
| City Area Code | 20 |
| Local Phone Number | 3139 2910 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
