Meta Platforms files 424B5: prospectus (424B)

The information in this prospectus supplement and accompanying prospectus is not complete and may be changed. This prospectus supplement and the accompanying prospectus are not an offer to sell these securities, and we are not soliciting offers to buy these securities, in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, NOVEMBER 3, 2026

PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED

We are offering $ of our % senior notes due 20 (the “20 notes”), $ of our % senior notes due 20 (the “20 notes”), $ of our % senior notes due 20 (the “20 notes”), $ of our % senior notes due 20 (the “20 notes”), and $ of our % senior notes due 20 (the “20 notes” and, together with the 20 notes, the 20 notes, the 20 notes, and the 20 notes, the “notes”).

We will pay interest on the notes on and of each year until maturity, beginning on , 2027. The notes will be our unsecured obligations and will rank equally with all of our other unsecured senior indebtedness from time to time outstanding. The notes of each series will be issued only in registered form in minimum denominations of

$2,000 and integral multiples of $1,000 in excess thereof.

We may redeem the notes of each series in whole or in part at any time prior to their maturity at the redemption prices described under “Description of Notes—Optional Redemption of the Notes.”

Investing in the notes involves risks. See “ Risk Factors ” beginning on page S-6 of this prospectus supplement and in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2026.

(1) Plus accrued interest from , 2026, if settlement occurs after that date.

(2) The underwriters have agreed to make a payment to us in an amount equal to approximately $ in connection with the offering, including expenses incurred by us in connection with the offering. See “Underwriting.”

The notes will not be listed on any securities exchange. Currently, there are no public markets for the notes.

This prospectus supplement and the accompanying prospectus are not intended to constitute an offer to, and the notes should not be purchased, held, or otherwise acquired by, a “specified foreign entity” as defined in Section 7701(a)(51)(B) of the Internal Revenue Code of 1986, as amended (“specified foreign entity”). Each purchaser of the notes, by accepting such notes, will be deemed to have represented, warranted, and agreed that it is not a “specified foreign entity.”

We expect that delivery of the notes will be made to investors in book-entry form only through the facilities of The Depository Trust Company on or about , 2026.

Joint Book-Running Managers

Citigroup Morgan Stanley

The following summary contains basic information about the notes and is not intended to be complete. It does not contain all the information that is important to you. For a more complete understanding of the notes, please refer to the section of this prospectus supplement entitled “Description of Notes.”

Issuer Meta Platforms, Inc.

Notes $ aggregate principal amount of % senior notes due 20 (the “20 notes”).

$ aggregate principal amount of % senior notes due 20 (the “20 notes”).

Interest Rate The 20 notes: % per annum, from , 2026, payable semi-annually in arrears.

Interest Payment Dates Interest on the notes will be paid semi-annually in arrears on and of each year, beginning on , 2027.

Optional Redemption of the Notes Prior to (i) with respect to the 20 notes, 20 ( months prior to the maturity date of such notes), (ii) with respect to the 20 notes, 20 ( months prior to the maturity date of such notes), (iii) with respect to the 20 notes, 20 ( months prior to the maturity date of such notes), (iv) with respect to the 20 notes, 20 ( months prior to the maturity date of such notes), and (v) with respect to the 20 notes, 20 , ( months prior to the maturity date of such notes) (each such date, a “Par Call Date”), a series of notes will be

redeemable as a whole or in part, at our option at any time and from time to time at the applicable “make whole” redemption price described under “Description of Notes—Optional Redemption of the Notes” plus, in each case, accrued and unpaid interest, if any, thereon to, but excluding, the applicable redemption date.

On or after the applicable Par Call Date, a series of notes will be redeemable as a whole or in part, at our option at any time and from time to time at a redemption price equal to 100% of the principal amount of the notes being redeemed, plus accrued and unpaid interest, if any, to, but excluding, the date of redemption.

Ranking The notes will be our unsecured and unsubordinated debt and will rank equally with our existing and future unsecured and unsubordinated debt. The notes will not be guaranteed by any of our subsidiaries and will rank structurally subordinate to all liabilities of our subsidiaries.

Use of Proceeds We intend to use the net proceeds from the offering for general corporate purposes. See “Use of Proceeds.”

Governing Law State of New York.

Risk Factors Investing in the notes involves risk. You should read the “Risk Factors” section of this prospectus supplement and in our latest Quarterly Report on Form 10-Q, and other periodic reports we have filed and may file with the SEC from time to time, for a discussion of factors to which you should refer and carefully consider prior to making an investment in the notes.

Trading The notes are new issues of securities with no established trading markets. We do not intend to apply for listing of the notes on any securities exchange or for quotation of the notes on any automated dealer quotation system. We have been advised by the underwriters that they presently intend to make markets in the notes after completion of the offering. However, they are under no obligation to do so and may discontinue any market-making activities at any time without any notice.

Trustee U.S. Bank Trust Company, National Association.