| Cover Page | Nov. 30, 2021 |
| Cover [Abstract] | |
| Entity Central Index Key | 0001023731 |
| Document Type | 8-K |
| Document Period End Date | Nov. 30, 2021 |
| Entity Registrant Name | 8X8 INC /DE/ |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-38312 |
| Entity Tax Identification Number | 77-0142404 |
| Entity Address, Address Line One | 675 Creekside Way |
| Entity Address, City or Town | Campbell |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 95008 |
| City Area Code | 408 |
| Local Phone Number | 727-1885 |
| Title of 12(b) Security | COMMON STOCK, PAR VALUE $.001 PER SHARE |
| Trading Symbol | EGHT |
| Security Exchange Name | NYSE |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
