QT IMAGING HOLDINGS, INC.

Up to $100,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

We may, from time to time in one or more offerings, offer and sell up to $100.0 million in the aggregate principal amount of our common stock, par value $0.0001 per share ("Common Stock"), preferred stock, debt securities, warrants and/or units, in one or more series or classes and in any combination, together or separately, in one or more offerings in amounts, at prices and on the terms that we will determine at the time of the offering and which will be set forth in a prospectus supplement to this prospectus and any related free writing prospectus.

We may offer these securities separately or together in units. This prospectus provides a general description of the securities we may offer. Each time we sell securities described herein, we will provide the specific terms of the securities offered in one or more supplements to this prospectus. we will provide prospective investors with a supplement to this prospectus that will specify the terms of the securities being offered. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. We may sell these securities to or through underwriters or dealers and also to other purchasers or through agents. We will set forth the names of any underwriters or agents, and any fees, conversions, or discount arrangements, in the applicable prospectus supplement. For additional information on the methods of sale, you should refer to the section entitled "Plan of Distribution" in this prospectus and in the applicable prospectus supplement. The prospectus supplement and any related free writing prospectus may add, update or change information contained in this prospectus. Please read carefully this prospectus, the applicable prospectus supplement, any related free writing prospectus, and the documents incorporated by reference before you invest in any of our securities. We may not sell any securities under this prospectus without delivery of the applicable prospectus supplement. This prospectus may not be used to offer or sell any securities unless accompanied by the applicable prospectus supplement.

You should read this prospectus and any prospectus supplement of amendment carefully before you invest in our securities. Our Common Stock is traded on the Nasdaq Stock Market LLC ("Nasdaq") under the symbol "QTI," and our public warrants are traded in the over-the-counter (OTC) market under the symbol "QTIWW." On March 26, 2026, the closing price of our Common Stock was $6.30, and on March 26, 2026, the closing price for our public warrants was $0.33.