Document

We have acted as counsel to Butterfly Network, Inc., a Delaware corporation (the “Company”), in connection with the issuance and sale of shares of the Class A common stock, $0.0001 par value (the “Common Stock”) of the Company having an aggregate offering price of up to $150,000,000 (the “Shares”), which the Company may issue and sell from time to time on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”). The Shares are being offered pursuant to the Company’s shelf registration statement on Form S-3ASR filed with the Securities and Exchange Commission (the “Commission”) on October 29, 2026 (the “Registration Statement”) and the related prospectus supplement dated October 29, 2026 (the “Prospectus Supplement”). The offering and sale of the Shares are being made pursuant to the Sales Agreement, dated October 29, 2026, by and between the Company and TD Securities (USA) LLC (the “Sales Agreement”).

We have examined copies of the Sales Agreement, the Registration Statement, the base prospectus that forms a part thereof and the Prospectus Supplement and such matters of fact and questions of law as we have considered appropriate for purposes of this letter. We have relied upon the certificate of incorporation and by-laws of the Company in effect on the date hereof, as and in the forms certified to us by the Company. We have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. In our examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to authentic original documents of all documents submitted to us as copies and the due authorization, execution and delivery of all documents by all persons other than the Company where authorization, execution and delivery are prerequisites to the effectiveness of such documents.

Based upon and subject to the foregoing and the other matters set forth herein, it is our opinion that the Shares have been duly authorized by the Company and when issued and paid for in accordance with the terms and conditions of the Sales Agreement in the manner contemplated by the Registration Statement and the Prospectus Supplement, the Shares will be validly issued, fully paid and nonassessable.

This opinion is being delivered solely for the benefit of the Company and such other persons as are entitled to rely upon it pursuant to applicable provisions of the Securities Act. This opinion may not be used, quoted, relied upon or referred to for any other purpose, nor may this opinion be used, quoted, relied upon or referred to by any other person, for any purpose, in each case without our prior written consent.

This opinion is based upon currently existing statutes, rules and regulations and judicial decisions and is rendered as of the date hereof, and we disclaim any obligation to advise you of any change in any of the foregoing sources of law or subsequent developments in law or changes in facts or circumstances which might affect any matters or opinions set forth herein.

This opinion letter shall be interpreted in accordance with the Core Opinion Principles jointly issued by the Committee on Legal Opinions of the American Bar Association’s Business Law Section and the Working Group on Legal Opinions Foundation as published in 74 Business Lawyer 815 (2019).

We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference to our firm in the Prospectus Supplement under the heading “Legal Matters.” In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder.


			Very truly yours,

			FOLEY HOAG LLP


			By:			/s/ Ryan Rourke Reed
						A Partner


			Seaport West 155 Seaport Boulevard Boston, MA 02210-2600 617 832 1000 main 617 832 7000 fax


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Re:						At the Market Offering