Free Writing Prospectus

Filed Pursuant to Rule 433 of the Securities Act of 1933

Issuer Free Writing Prospectus dated November 4, 2013

Registration No. 333-191552



Twitter, Inc.

Update and Supplement to Preliminary Prospectus

Dated October 24, 2013

This free writing prospectus relates to the initial public offering of common stock of Twitter, Inc. and should be read together with the preliminary prospectus dated October 24, 2013 (the “Preliminary Prospectus”) that was included in Amendment No. 3 to the Registration Statement on Form S-1 relating to this offering of our common stock. On November 4, 2013, Twitter filed Amendment No. 4 to the Registration Statement on Form S-1 relating to this offering of our common stock (“Amendment No. 4”), which may be accessed through the following link:

References to “Twitter,” “we,” “us” and “our” are used in the manner described in the Preliminary Prospectus. The following information is set forth in Amendment No. 4 and supplements and updates the information contained in the Preliminary Prospectus.

Increase to Estimated Initial Offering Price Range

The estimated initial public offering price per share of our common stock set forth in the Preliminary Prospectus was $17.00 to $20.00, and has been increased to $23.00 to $25.00 per share.

Update to Risk Factor

The disclosure set forth in the Preliminary Prospectus under “Risk Factors—We are currently, and expect to be in the future, party to intellectual property rights claims that are expensive and time consuming to defend, and, if resolved adversely, could have a significant impact on our business, financial condition or operating results” has been updated in its entirety to read as follows:

We are currently, and expect to be in the future, party to intellectual property rights claims that are expensive and time consuming to defend, and, if resolved adversely, could have a significant impact on our business, financial condition or operating results.

Companies in the Internet, technology and media industries own large numbers of patents, copyrights, trademarks and trade secrets, and frequently enter into litigation based on allegations of infringement, misappropriation or other violations of intellectual property or other rights. Many companies in these industries, including many of our competitors, have substantially larger patent and intellectual property portfolios than we do, which could make us a target for litigation as we may not be able to assert counterclaims against parties that sue us for patent, or other intellectual property infringement. In addition, various “non-practicing entities” that own patents and other intellectual property rights often attempt to aggressively assert claims in order to extract value from technology companies. From time to time we receive claims from third parties which allege that we have infringed upon their intellectual property rights. In this regard, we recently received a letter from International Business Machines Corporation, or IBM, alleging that we infringe on at least three U.S. patents held by IBM, and inviting us to negotiate a business resolution of the allegations. The three patents specifically identified by IBM in the letter were U.S. Patent No. 6,957,224: Efficient retrieval of uniform resource locators, U.S. Patent No. 7,072,849: Method for presenting advertising in an interactive service and U.S. Patent No. 7,099,862: Programmatic discovery of common contacts. Based upon our preliminary review of these patents, we believe we have meritorious defenses to IBM’s allegations, although there can be no assurance that we will be successful in defending against these allegations or reaching a business resolution that is satisfactory to us. Further, from time to time we may introduce new products and services, including in areas where we currently do not have an offering, which could increase our exposure to patent and other intellectual property claims from competitors and non-practicing entities. In addition, although our standard terms and conditions for our Promoted Products and public APIs do not provide advertisers and platform partners with indemnification for intellectual property claims against them, some of our agreements with advertisers, platform partners and data partners require us to indemnify them for certain intellectual property claims against them, which could require us to incur considerable costs in defending such claims, and may require us to pay significant damages in the event of an adverse ruling. Such advertisers, platform partners and data partners may also discontinue use of our products, services and technologies as a result of injunctions or otherwise, which could result in loss of revenue and adversely impact our business.

We presently are involved in a number of intellectual property lawsuits, and as we face increasing competition and gain an increasingly high profile, we expect the number of patent and other intellectual property claims against us to grow. There may be intellectual property or other rights held by others, including issued or pending patents, that cover significant aspects of our products and services, and we cannot be sure that we are not infringing or violating, and have not infringed or violated, any third



party intellectual property rights or that we will not be held to have done so or be accused of doing so in the future. Any claim or litigation alleging that we have infringed or otherwise violated intellectual property or other rights of third parties, with or without merit, and whether or not settled out of court or determined in our favor, could be time-consuming and costly to address and resolve, and could divert the time and attention of our management and technical personnel. Some of our competitors have substantially greater resources than we do and are able to sustain the costs of complex intellectual property litigation to a greater degree and for longer periods of time than we could. The outcome of any litigation is inherently uncertain, and there can be no assurances that favorable final outcomes will be obtained in all cases. In addition, plaintiffs may seek, and we may become subject to, preliminary or provisional rulings in the course of any such litigation, including potential preliminary injunctions requiring us to cease some or all of our operations. We may decide to settle such lawsuits and disputes on terms that are unfavorable to us. Similarly, if any litigation to which we are a party is resolved adversely, we may be subject to an unfavorable judgment that may not be reversed upon appeal. The terms of such a settlement or judgment may require us to cease some or all of our operations or pay substantial amounts to the other party. In addition, we may have to seek a license to continue practices found to be in violation of a third party’s rights. If we are required, or choose to enter into royalty or licensing arrangements, such arrangements may not be available on reasonable terms, or at all, and may significantly increase our operating costs and expenses. As a result, we may also be required to develop or procure alternative non-infringing technology or discontinue use of the technology. The development or procurement of alternative non-infringing technology could require significant effort and expense or may not be feasible. An unfavorable resolution of the disputes and litigation referred to above could adversely affect our business, financial condition and operating results.

Twitter has filed a registration statement (including the Preliminary Prospectus) with the Securities and Exchange Commission (the “SEC”) for the offering to which this communication relates. Before you invest, you should read the Preliminary Prospectus in that registration statement and other documents Twitter has filed with the SEC for more complete information about Twitter and this offering. You may get these documents for free by visiting EDGAR on the SEC web site at Alternatively, a copy of the Preliminary Prospectus may be obtained from Goldman, Sachs & Co. if you request it by calling toll-free +1 866 471 2526 or by emailing