Form 424B3 Swarmer, Inc

Filed pursuant to Rule 424(b)(3)

Registration No. 333-296678

Prospectus Supplement No. 2

(To Prospectus dated June 15, 2026)

SWARMER, Inc

This prospectus supplement updates, amends and supplements the prospectus dated June 15, 2026 (the “Prospectus”), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-296678) and is being filed to update, amend and supplement the information included in the Prospectus with information contained in our Current Report on Form 8-K, which was filed with the Securities and Exchange Commission (the “SEC”) on August 19, 2026 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement. Capitalized terms used in this prospectus supplement and not otherwise defined herein have the meanings specified in the Prospectus.

This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extent that the information in this prospectus supplement updates or supersedes the information contained in the Prospectus. Please keep this prospectus supplement with your Prospectus for future reference.

Our common stock, par value $0.00001 per share (“common stock”), is currently listed on The Nasdaq Capital Market under the symbol “SWMR”. On August 18, 2026, the closing price of our common stock was $46.86 per share.

Investing in our securities involves risks that are described in the “Risk Factors” section of the Prospectus.

Neither the SEC nor any state securities commission has approved or disapproved of the securities to be issued under the Prospectus or this prospectus supplement or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is August 19, 2026.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Swarmer, Inc

(Exact name of Registrant as Specified in Its Charter)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01. Results of Operations and Financial Condition.

As of August 19, 2026, Swarmer, Inc had 15,936,981 shares of common stock outstanding after giving effect to the issuance of 3,997,762 shares of common stock upon the exercise of certain stock options.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.