| Document and Entity Information | Sep. 26, 2024 |
| Document Information: | |
| Document Type | 8-K |
| Document Period End Date | Sep. 26, 2024 |
| Entity Registrant Name | Renalytix plc |
| Entity Incorporation State Country Code | X0 |
| Entity File Number | 001-39387 |
| Entity Tax Identification Number | 00-0000000 |
| Entity Address Address Line 1 | 2 Leman Street |
| Entity Address City Or Town | London |
| Entity Address Postal Zip Code | E1W 9US |
| Entity Address Country | GB |
| 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 |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001811115 |
| Amendment Flag | false |
| Ordinary shares, nominal value £0.0025 per ordinary share [Member] | |
| Document Information: | |
| Security 12b Title | Ordinary shares, nominal value £0.0025 per ordinary share |
| No Trading Symbol Flag | true |
| Security Exchange Name | NASDAQ |
| American Depositary Shares, each representing two ordinary shares, nominal value £0.0025 per ordinary share [Member] | |
| Document Information: | |
| Security 12b Title | American Depositary Shares, each representing two ordinary shares, nominal value £0.0025 per ordinary share |
| Security Exchange Name | NASDAQ |
| Trading Symbol | RNLX |
