#1Western Digital. Third Quarter of Fiscal 2019 Earnings Presentation April 29, 2019 ©2019 Western Digital Corporation or its affiliates. All rights reserved.#2Forward-Looking Statements Safe Harbor | Disclaimers This presentation contains forward-looking statements that involve risks and uncertainties, including, but not limited to, statements regarding our product and technology portfolio; market positioning; business strategies and growth opportunities; our expected future financial performance; cost saving initiatives; restructuring activities; and market and flash industry trends. Forward-looking statements should not be read as a guarantee of future performance or results, and will not necessarily be accurate indications of the times at, or by, which such performance or results will be achieved, if at all. Forward-looking statements are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in or suggested by the forward-looking statements. Key risks and uncertainties include volatility in global economic conditions; business conditions and growth in the storage ecosystem; impact of restructuring activities and cost saving initiatives; impact of competitive products and pricing; market acceptance and cost of commodity materials and specialized product components; actions by competitors; unexpected advances in competing technologies; our development and introduction of products based on new technologies and expansion into new data storage markets; risks associated with acquisitions, mergers and joint ventures; difficulties or delays in manufacturing; the outcome of legal proceedings; and other risks and uncertainties listed in the company's filings with the Securities and Exchange Commission (the "SEC") and available on the SEC's website at www.sec.gov, including our most recently filed periodic report, to which your attention is directed. We do not undertake any obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise, except as required by law. This presentation includes references to non-GAAP financial measures. Reconciliations of the differences between the non-GAAP measures provided in this presentation to the comparable GAAP financial measures are included in the appendix and in the Investor Relations section of our website. We have not fully reconciled our non-GAAP financial measure guidance to the most directly comparable GAAP measures because material items that impact these measures are not in our control and/or cannot be reasonably predicted. Accordingly, a full reconciliation of the non-GAAP financial measure guidance to the corresponding GAAP measures is not available without unreasonable effort. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 2#3Executive Summary S→ ° RESULTS GENERALLY CONSISTENT WITH OUR EXPECTATIONS . • . Incremental improvement in demand for capacity enterprise and client compute Flash industry dynamics remain challenging Expecting both flash and HDD demand to further improve for the balance of CY19 PRODUCT PORTFOLIO STRONGEST IN OUR HISTORY • • O FLASH Began shipments of internally developed BICS4 NVMe client SSDs and BiCS3 NVMe enterprise SSDs Leading the industry's transition to BiCS4 technology BiCS4 to become highest volume runner in terms of flash output in second half of CY19 HDD Capacity Enterprise-continue to lead in areal density and capacity points Leading the industry's transition to 14TB capacity • On track to launch 16TB and 18TB energy assisted recording drives in CY19 EXECUTING WELL TO COST AND EXPENSE REDUCTION PLANS • On track to achieve projected non-GAAP operating expense reductions by September 2019 quarter and non-GAAP cost reductions exiting the December 2019 quarter WELL POSITIONED TO EMERGE STRONGER . Significant expansion of product portfolio, deeper customer engagement and rightsized manufacturing footprint Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19#4Financial Results Non-GAAP Non-GAAP Operating Revenue Gross margin EPS cash flow $3.7B * 25.3% $0.17* $204M 325 55.01 *Includes the impact associated with lower of cost or market inventory reserves of a 300 basis point reduction to gross margin and $0.37 reduction to non-GAAP EPS. See Appendix for reconciliations of GAAP to Non-GAAP financial measures. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 11.08 4/29/19 4#5$(M) Revenue Mix $4,233 $1,074 $945 $2,214 $3,674 $1,245 $804 $1,625 DATA CENTER DEVICES & SOLUTIONS • • Demand for capacity enterprise drives better than expected Initial revenue shipments of enterprise NVMe SSD solutions and on track to accelerate ramp throughout CY19 CLIENT SOLUTIONS • Continue to expand our presence in external SSDs sold through retail Average capacity per unit for flash devices grew 44% year-over-year CLIENT DEVICES Q2 FY19 Q3 FY19 • Client Devices O Client Solutions ■Data Center Devices & Solutions Mobile embedded revenue declined due to weak handset demand Notebook and desktop revenue decreased due to seasonality and flash price declines Western Digital. © 2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 5#6Cash Flow Walk Cash Flow ($ Millions) $4,130 Cash & Marketable Securities $204 ($314) ($146) ($73) $3,801 Cash & Marketable Securities Q2 FY19 Operating Cash Flow Capex Dividend Other Q3 FY19 (1) CAPEX includes purchases of property, plant and equipment, net, and the activity related to Flash Ventures, net Other primarily consists of employee stock plans, net, repayment of debt and other investing activities Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 6#7Non-GAAP Financial Results $ Millions, except EPS Q3 FY19 Q2 FY19 Q3 FY18 Q/Q Y/Y Revenue Gross Margin %* $3,674 $4,233 $5,013 (13%) (27%) 25.3%* 31.3% 43.4% ~(600) BPS ~(1800) BPS Operating Expenses $742 $738 $850 ~ Flat (13%) Operating Income $186 $589 $1,324 (68%) (86%) Interest and Other Expense, net $88 $93 $137 (5%) (36%) EPS* $0.17* $1.45 $3.63 (88%) (95%) Operating Cash Flow $204 $469 $1,027 (57%) (80%) Free Cash Flow ($110) $24 $616 NM NM *Includes the impact associated with lower of cost or market inventory reserves of a 300 basis point reduction to gross margin and $0.37 reduction to non-GAAP EPS. For reconciliations of GAAP to Non-GAAP financial measures, see the Appendix and Quarterly Fact Sheet. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 7#8Quarterly Fact Sheet Amounts in millions, except Average Selling Price (ASP), percentages, and working capital-related metrics REVENUE EXABYTE METRICS TECHNOLOGY CASH CASH FLOWS (10%) 5% THREE MONTHS ENDED 9/28/2018 12/28/2018 3/29/2019 $ 2,650 932 1,446 $ 5,028 $ 2,214 945 1,074 $ 4,233 $ 1,625 804 1,245 $ 3,674 ៩ ៩ ៩ 6% (6%) 9% 28% 6% (3%) (17%) 5% (15%) 13% (5%) 11% $ 2,494 $ 2,060 $ 2,064 $ 2,173 $ 1,610 32% 44% 27% 29% 38.0% 21% 25.3% $ 2,754 $ 2,363 3/30/2018 6/29/2018 Client Devices¹ $ 2,311 $ 2,474 Client Solutions¹ 1,042 1,031 1,660 1,612 $ 5,013 $ 5,117 7% Data Center Devices & Solutions¹ Total Revenue Q/Q Change in HDD Exabytes Sold² Q/Q Change in Flash Exabytes Sold² Q/Q Change in Total Exabytes Sold² HDD Revenue Flash Revenue HDD Non-GAAP Gross Margin³ Flash Non-GAAP Gross Margin³ Total Non-GAAP Gross Margin³ Cash and Cash Equivalents Available-for-Sale (AFS) Securities Total Cash, Cash Equivalents, and AFS Securities Cash Flows provided by Operating Activities Purchases of Property, Plant and Equipment, net Activity Related to Flash Ventures, net Free Cash Flow4 $ 2,640 32% 51% 41.0% $ 5,005 116 $ 2,373 33% 55% 43.4% $ 4,963 113 $ 5,076 $ 1,027 (213) (198) (35) $ 616 $ 638 $ 5,121 $ 863 (190) $ 2,534 $ 4,646 116 $ 4,762 $ 705 (277) 35% 31.3% $ 4,013 117 $ 4,130 $ 3,682 119 $ 3,801 $ 204 (222) $ 469 (220) 29 (225) (92) $ 457 $ 24 $ (110) WORKING CAPITAL RELATED Days Sales Outstanding Days Inventory Outstanding Days Payables Outstanding 36 39 40 37 30 79 82 84 98 101 (71) (70) (64) (64) (55) Cash Conversion Cycle 44 51 60 71 76 FLASH METRICS Q/Q Change in ASP/Gigabytes² (2%) (8%) (16%) (18%) (23%) HDD METRICS Client Compute Units Non-Compute Units 5 17.6 17.8 16.3 14.0 12.9 11.2 13.7 11.2 11.1 9.3 Data Center Units 7.6 7.5 6.6 5.1 5.6 Total HDD Units 36.4 39.0 34.1 30.2 27.8 HDD ASP⁹ $ 72 $ 70 $ 72 $ 67 $73 Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 8#9Quarterly Fact Sheet Footnotes FORMULAS Days Sales Outstanding (DSO) = Accounts Receivable/ (Revenue / 91 days) Days Inventory Outstanding (DIO) = Inventories / (Cost of Revenue / 91 days) Days Payables Outstanding (DPO) = Accounts Payable (including Accounts Payable to Related Parties) / (Cost of Revenue / 91 days) Cash Conversion Cycle = DSO + DIO - DPO FOOTNOTES Client Devices is comprised of notebook and desktop HDD, consumer electronics HDD, client SSD, embedded, wafer sales and licensing and royalties. Client Solutions is comprised of branded HDD, branded flash, removables and licensing and royalties. Data Center Devices and Solutions is comprised of enterprise HDD, enterprise SSD, data center software, data center solutions and licensing and royalties. Excludes licensing, royalties, and non-memory products. ③ Refer to the GAAP to non-GAAP reconciliation slides within the Appendix for further details. 4 Free cash flow is a non-GAAP financial measure defined as cash flows provided by operating activities less purchases of property, plant and equipment, net of proceeds from sales of property, plant and equipment, and the activity related to Flash Ventures, net. We consider free cash flow to be useful as an indicator of our overall liquidity, as the amount of free cash flow generated in any period is representative of cash that is available for strategic opportunities or other business purposes including, among others, investing in the company's business, making strategic acquisitions, strengthening the balance sheet, repaying debt, paying dividends and repurchasing stock. Free cash flow is not an alternative for measures prepared in accordance with GAAP and may be different from non-GAAP free cash flow measures used by other companies. 5 Client compute products consist primarily of desktop and notebook HDDs, excluding those sold through retail channels. 6 Non-compute products consist of retail channel and consumer electronics HDDs. Data center products consist of enterprise HDDs (high-capacity and performance) and enterprise systems. 8 HDD Unit volume excludes data storage systems and media. 9 HDD ASP is calculated by dividing HDD revenue by HDD units. Data storage systems are excluded from this calculation, as data storage systems ASP is measured on a per system basis rather than a per drive basis. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 9#10Debt Tranches and Interest Rates Debt Base Rate Maturity Principal Balance Outstanding as of 3/29/2019 (in millions) Applicable RatesA Convertible Debt Due 2020 B Revolver drawn C, D Term Loan A-1D Term Loan B-4D Convertible Debt Due 2024F Sr. Unsecured Notes Due 2026G TOTAL 0.500% October 15, 2020 35 0.500% L+150 February 27, 2023 0 3.999% L+150 February 27, 2023 4,896 3.879%E L+175 April 29, 2023 2,431 4.249% 1.500% February 1, 2024 1,100 1.500% 4.750% February 15, 2026 2,300 4.750% $ 10,762 3.895%H A. All-in applicable rates as of March 29, 2019. Applicable spread for Term Loan A-1 and Revolver over LIBOR based on credit ratings as of March 29, 2019. B. Debt assumed in connection with the acquisition of SanDisk Corporation in May 2016. C. Revolver capacity: $2.25 billion, none of which was drawn as of March 29, 2019. D. Term Loan A-1, Term Loan B-4, and Revolver have a LIBOR floor of Obps. E. Reflects impact of the interest rate swaps that effectively fix LIBOR on $2 billion of floating-rate debt at 2.21% through May 2020 and 2.60% through February 2023. F. Initial conversion price of $121.91 per share. Notes are callable beginning February 5, 2021. G. Notes are callable beginning November 15, 2025. H. Weighted average interest rate, including impact of interest rate swaps, based on principal balances outstanding as of March 29, 2019. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 10 10#11Western Digital. Appendix © 2018 Western Digital Corporation or its affiliates. All rights reserved. | WESTERN DIGITAL CONFIDENTIAL 4/29/19#12GAAP to Non-GAAP Reconciliation In millions; unaudited GAAP COST OF REVENUE Amortization of acquired intangible assets Stock-based compensation expense Charges related to cost saving initiatives Manufacturing underutilization charges NON-GAAP COST OF REVENUE 3/30/2018 $ 3,086 (235) (11) (1) GAAP GROSS PROFIT Amortization of acquired intangible assets Stock-based compensation expense Charges related to cost saving initiatives $ 2,839 $ 1,927 235 11 1 Manufacturing underutilization charges NON-GAAP GROSS PROFIT GAAP OPERATING EXPENSES Amortization of acquired intangible assets Stock-based compensation expense Employee termination, asset impairment and other charges Acquisition-related charges Charges related to cost saving initiatives Other NON-GAAP OPERATING EXPENSES GAAP OPERATING INCOME (LOSS) Cost of revenue adjustments Operating expense adjustments NON-GAAP OPERATING INCOME GAAP INTEREST AND OTHER EXPENSE, NET Convertible debt activity, net Debt extinguishment costs Other NON-GAAP INTEREST AND OTHER EXPENSE, NET THREE MONTHS ENDED 12/28/2018 3/29/2019 $ 3,189 (215) $ 3,095 (188) (13) (13) (6) (49) $ 2,906 $ 1,044 215 13 (148) $ 2,746 $ 579 188 13 6 - $ 2,174 $1,013 (41) 49 $ 1,327 148 $ 928 $ 868 $ 973 (41) (41) (91) (66) (71) (35) (20) (76) (2) 3 (2) (3) 3 (1) $ 850 $ 738 (40) $ 742 $ 914 $ 176 $ (394) 247 283 349 163 130 231 $ 1,324 $ 589 $ 186 $ (1,042) 3 $ (95) 6 $ (83) 7 894 8 $ (137) (4) $ (93) (12) $ (88) $ 104 (55) $ 49 4/29/19 GAAP INCOME TAX EXPENSE (BENEFIT) Income tax adjustments $(189) $ 568 259 (496) NON-GAAP INCOME TAX EXPENSE $ 70 $ 72 Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 12 12#13GAAP to Non-GAAP Reconciliation In millions, except EPS and percentages; unaudited THREE MONTHS ENDED 12/28/2018 $ (487) 3/29/2019 $ (581) GAAP NET INCOME (LOSS) Amortization of acquired intangible assets Stock-based compensation expense Employee termination, asset impairment and other charges Acquisition-related charges Charges related to cost saving initiatives Manufacturing underutilization charges Convertible debt activity, net Debt extinguishment costs Other Income tax adjustments NON-GAAP NET INCOME DILUTED INCOME (LOSS) PER COMMON SHARE GAAP Non-GAAP DILUTED WEIGHTED AVERAGE SHARES OUTSTANDING GAAP Non-GAAP GAAP GROSS MARGIN Amortization of acquired intangible assets Stock-based compensation expense Charges related to cost saving initiatives Manufacturing underutilization charges NON-GAAP GROSS MARGIN HDD non-GAAP gross margin Flash non-GAAP gross margin NON-GAAP GROSS MARGIN 3/30/2018 $ 61 276 102 35 2 (2) 3 894 5 (259) $ 1,117 $0.20 $ 3.63 308 308 256 79 20 229 84 76 3 8 49 148 6 7 (3) 496 $ 424 28 55 $ 49 $ (1.68) $ 1.45 290 293 THREE MONTHS ENDED* $ (1.99) $ 0.17 292 294 3/30/2018 6/29/2018 9/28/2018 12/28/2018 3/29/2019 38.4% 36.2% 33.1% 24.7% 15.8% 4.7% 4.6% 4.7% 5.1% 5.1% 0.2% 0.2% 0.2% 0.3% 0.4% 0.1% 0.0% 0.0% 0.1% 1.1% 4.0% 43.4% 41.0% 38.0% 31.3% 25.3% 33% 55% 43.4% 32% 51% 41.0% 32% 44% 38.0% 27% 35% 31.3% 29% 21% 25.3% *GAAP gross margin is calculated by dividing GAAP gross profit by revenue. Non-GAAP gross margin is calculated by dividing non-GAAP gross profit by revenue. HDD non-GAAP gross margin is calculated by dividing HDD non-GAAP gross profit by HDD revenue. Flash non-GAAP gross margin is calculated by dividing Flash non-GAAP gross profit by Flash revenue. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 13#14Footnotes for GAAP to Non-GAAP Reconciliation This presentation contains the following financial measures that are not in accordance with U.S. generally accepted accounting principles ("GAAP"): non-GAAP cost of revenue; non-GAAP gross profit; non-GAAP operating expenses; non-GAAP operating income; non-GAAP interest and other expense, net; non-GAAP income tax expense; non-GAAP net income; non-GAAP diluted income per common share; and non-GAAP gross margin ("Non-GAAP measures"). These Non-GAAP measures are not in accordance with, or an alternative for, measures prepared in accordance with GAAP and may be different from Non-GAAP measures used by other companies. The company believes the presentation of these Non-GAAP measures, when shown in conjunction with the corresponding GAAP measures, provides useful information to investors for measuring the company's earnings performance and comparing it against prior periods. Specifically, the company believes these Non-GAAP measures provide useful information to both management and investors as they exclude certain expenses, gains and losses that the company believes are not indicative of its core operating results or because they are consistent with the financial models and estimates published by many analysts who follow the company and its peers. As discussed further below, these Non-GAAP measures exclude the amortization of acquired intangible assets, stock- based compensation expense, employee termination, asset impairment and other charges, acquisition-related charges, charges related to cost saving initiatives, manufacturing underutilization charges, convertible debt activity, debt extinguishment costs, other adjustments, and income tax adjustments, and the company believes these measures along with the related reconciliations to the GAAP measures provide additional detail and comparability for assessing the company's results. These Non-GAAP measures are some of the primary indicators management uses for assessing the company's performance and planning and forecasting future periods. These measures should be considered in addition to results prepared in accordance with GAAP, but should not be considered a substitute for, or superior to, GAAP results. As described above, the company excludes the following items from its Non-GAAP measures: Amortization of acquired intangible assets. The company incurs expenses from the amortization of acquired intangible assets over their economic lives. Such charges are significantly impacted by the timing and magnitude of the company's acquisitions and any related impairment charges. Stock-based compensation expense. Because of the variety of equity awards used by companies, the varying methodologies for determining stock-based compensation expense, the subjective assumptions involved in those determinations, and the volatility in valuations that can be driven by market conditions outside the company's control, the company believes excluding stock-based compensation expense enhances the ability of management and investors to understand and assess the underlying performance of its business over time and compare it against the company's peers, a majority of whom also exclude stock-based compensation from their non-GAAP results. Employee termination, asset impairment and other charges. From time-to-time, in order to realign the company's operations with anticipated market demand or to achieve cost synergies from the integration of acquisitions, the company may terminate employees and/or restructure its operations. From time-to-time, the company may also incur charges from the impairment of intangible assets and other long-lived assets. These charges (including any reversals of charges recorded in prior periods) are inconsistent in amount and frequency, and the company believes are not indicative of the underlying performance of its business. Acquisition-related charges. In connection with the company's business combinations, the company incurs expenses which it would not have otherwise incurred as part of its business operations. These expenses include third-party professional service and legal fees, third-party integration services, severance costs, non-cash adjustments to the fair value of acquired inventory, contract termination costs, and retention bonuses. The company may also experience other accounting impacts in connection with these transactions. These charges and impacts are related to acquisitions, are inconsistent in amount and frequency, and the company believes are not indicative of the underlying performance of its business. Charges related to cost saving initiatives. In connection with the transformation of the company's business combinations, the company has incurred charges related to cost saving initiatives which do not qualify for special accounting treatment as exit or disposal activities. These charges, which the company believes are not indicative of the underlying performance of its business, primarily relate to costs associated with rationalizing the company's channel partners or vendors, transforming the company's information systems infrastructure, integrating the company's product roadmap, and accelerated depreciation of assets. Manufacturing underutilization charges. In response to the current flash business conditions, the company is reducing its wafer starts at its flash-based memory manufacturing facilities operated through its strategic partnership with Toshiba Memory Corporation (TMC). The temporary abnormal reduction in output has resulted in flash manufacturing underutilization charges which are expensed as incurred. These charges are inconsistent in amount and frequency, and the company believes these charges are not part of the ongoing operation of its business. Convertible debt activity, net. The company excludes non-cash economic interest expense associated with its convertible notes, the gains and losses on the conversion of its convertible senior notes and call option, and unrealized gains and losses related to the change in fair value of the exercise option and call option. These charges and gains and losses do not reflect the company's operating results, and the company believes are not indicative of the underlying performance of its business. Debt extinguishment costs. From time-to-time, the company replaces its existing debt with new financing at more favorable interest rates or utilizes available capital to settle debt early, both of which generate interest savings in future periods. The company incurs debt extinguishment charges consisting of the costs to call the existing debt and/or the write-off of any related unamortized debt issuance costs. These gains and losses do not reflect the company's operating results, and the company believes are not indicative of the underlying performance of its business. Other adjustments. From time-to-time, the company sells or impairs investments or other assets which are not considered necessary to its business operations, or incurs other charges or gains that the company believes are not a part of the ongoing operation of its business. The resulting expense or benefit is inconsistent in amount and frequency. Income tax adjustments. Income tax adjustments include the difference between income taxes based on a forecasted annual non-GAAP tax rate and a forecasted annual GAAP tax rate as a result of the timing of certain non-GAAP pre-tax adjustments. The income tax adjustments include the company's final adjustments for the tax effects of the Tax Cuts and Jobs Act allowed within the one-year measurement period that ended on December 22, 2018, as well as estimates related to the current status of the rules and regulations governing the transition to the Tax Cuts and Jobs Act. These adjustments are excluded because they are infrequent and the company believes that they are not indicative of the underlying performance of its business. Western Digital. ©2019 Western Digital Corporation or its affiliates. All rights reserved. 4/29/19 14