| Cover | Aug. 17, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 13, 2021 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-36616 |
| Entity Registrant Name | Nxt-ID, Inc. |
| Entity Central Index Key | 0001566826 |
| Entity Tax Identification Number | 46-0678374 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | Nxt-ID, Inc. |
| Entity Address, Address Line Two | 288 Christian Street |
| Entity Address, Address Line Three | Hangar C 2nd Floor |
| Entity Address, City or Town | Oxford |
| Entity Address, State or Province | CT |
| Entity Address, Postal Zip Code | 06478 |
| City Area Code | (203) |
| Local Phone Number | 266-2103 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | NXTD |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
