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 4, 2026

PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED

APRIL 30, 2026 Meta Platforms, Inc.

% Senior Notes due 20 % Senior Notes due 20

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”), 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, the 20 notes, and the 20 notes, the “notes”).

We will pay interest on the notes on 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 100,000 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.” In addition, we may redeem any series of the notes in whole, but not in part, at any time at our option in the event of certain changes in the tax laws of the United States that would require us to pay additional amounts as described under “Description of Notes—Redemption for Tax Reasons.”

Investing in the notes involves risks. See “ Risk Factors ” beginning on page S-8 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.”

Currently, there are no public markets for the notes.

We intend to apply to list the notes on the Nasdaq Bond Exchange (“Nasdaq”). The listing application will be subject to approval by

Nasdaq. We currently expect trading in the notes on Nasdaq to begin within 30 days after the original issue date. If such a listing is obtained, we have no obligation to maintain such listing, and we may delist the notes at any time. Currently, there is no public market 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 a common depositary of Clearstream Banking S.A.

(“Clearstream”) and Euroclear Bank S.A./N.V. (“Euroclear” and, together with Clearstream, the “clearing systems”) on or about , 2026.

Joint Book-Running Managers

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.

Issuer Legal Entity Identifier BQ4BKCS1HXDV9HN80Z93

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 annually in arrears.

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

Currency of Payments All payments of interest on, principal of, and any redemption price for, or additional amounts as described under “Description of Notes—Payment of Additional Amounts,” if any, with respect to, the notes will be made in euros. If we are unable to obtain euros in amounts sufficient to make a required payment under the notes due to the imposition of exchange controls or other circumstances beyond our control (including the dissolution of the European Monetary Union) or if the euro is no longer being used by the then Member States of the European Monetary Union that have adopted the euro as their currency or for the settlement of transactions by public institutions of or within the international banking community, then all payments in respect of the notes will be made in U.S. dollars until the euro is again available to us or so used. See “Description of Notes—Issuance in Euro; Payment on the Notes.”

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), (v) with respect to the 20 notes, 20 , ( months prior to the maturity date of such notes), and (vi) 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.