| Document and Entity Information | Nov. 26, 2021 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001836981 |
| Document Type | 8-K |
| Document Period End Date | Nov. 26, 2021 |
| Entity Registrant Name | GigCapital4, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-40031 |
| Entity Tax Identification Number | 85-4164597 |
| Entity Address, Address Line One | 1731 Embarcadero Rd. |
| Entity Address, Address Line Two | Suite 200 |
| Entity Address, City or Town | Palo Alto |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94303 |
| City Area Code | 650 |
| Local Phone Number | 276-7040 |
| Written Communications | false |
| Soliciting Material | true |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Units Each Consisting Of One Share Of Common Stock 0.0001 Par Value And One Third Of One Redeemable Warrant [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Units, each consisting of one share of common stock, $0.0001 par value, and one-third of one redeemable warrant |
| Trading Symbol | GIGGU |
| Security Exchange Name | NASDAQ |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common stock, $0.0001 par value |
| Trading Symbol | GIG |
| Security Exchange Name | NASDAQ |
| Redeemable Warrants Each Full Warrant Exercisable For One Share Of Common Stock At An Exercise Price Of 11.50 Per Share [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Redeemable warrants, each full warrant exercisable for one share of common stock at an exercise price of $11.50 per share |
| Trading Symbol | GIGGW |
| Security Exchange Name | NASDAQ |
