| Document and Entity Information | Sep. 17, 2021 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001719489 |
| Document Type | 8-K |
| Document Period End Date | Sep. 17, 2021 |
| Entity Registrant Name | KALEYRA, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38320 |
| Entity Tax Identification Number | 82-3027430 |
| Entity Address, Address Line One | Via Marco D’Aviano, 2, |
| Entity Address, City or Town | Milano MI |
| Entity Address, Country | IT |
| Entity Address, Postal Zip Code | 20131 |
| City Area Code | 39 02 |
| Local Phone Number | 288 5841 |
| 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 |
| Common Stock Par Value 0.0001 Per Share 2 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | KLR |
| Security Exchange Name | NYSE |
| Warrants At An Exercise Price Of 11.50 Per Share Of Common Stock 1 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants, at an exercise price of $11.50 per share of Common Stock |
| Trading Symbol | KLR WS |
| Security Exchange Name | NYSE |
