| Document and Entity Information | Feb. 25, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001719395 |
| Document Type | 8-K |
| Document Period End Date | Feb. 25, 2021 |
| Entity Registrant Name | EARGO, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39616 |
| Entity Tax Identification Number | 27-3879804 |
| Entity Address, Address Line One | 1600 Technology Drive |
| Entity Address, Address Line Two | 6th Floor |
| Entity Address, City or Town | San Jose |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 95110 |
| City Area Code | (650) |
| Local Phone Number | 351-7700 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.0001 par value per share |
| Trading Symbol | EAR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
